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Li Y, Ling P, Li Y, Wang Y, Li G, Qiu C, Wang J, Gong K. miR-138-5p ameliorates intestinal barrier disruption caused by acute superior mesenteric vein thrombosis injury by inhibiting the NLRP3/HMGB1 axis. PeerJ 2024; 12:e16692. [PMID: 38406274 PMCID: PMC10893868 DOI: 10.7717/peerj.16692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 11/28/2023] [Indexed: 02/27/2024] Open
Abstract
Background Acute superior mesenteric venous thrombosis (ASMVT) decreases junction-associated protein expression and intestinal epithelial cell numbers, leading to intestinal epithelial barrier disruption. Pyroptosis has also recently been found to be one of the important causes of mucosal barrier defects. However, the role and mechanism of pyroptosis in ASMVT are not fully understood. Methods Differentially expressed microRNAs (miRNAs) in the intestinal tissues of ASMVT mice were detected by transcriptome sequencing (RNA-Seq). Gene expression levels were determined by RNA extraction and reverse transcription-quantitative PCR (RT-qPCR). Western blot and immunofluorescence staining analysis were used to analyze protein expression. H&E staining was used to observe the intestinal tissue structure. Cell Counting Kit-8 (CCK-8) and fluorescein isothiocyanate/propidine iodide (FITC/PI) were used to detect cell viability and apoptosis, respectively. Dual-luciferase reporter assays prove that miR-138-5p targets NLRP3. Results miR-138-5p expression was downregulated in ASMVT-induced intestinal tissues. Inhibition of miR-138-5p promoted NLRP3-related pyroptosis and destroyed tight junctions between IEC-6 cells, ameliorating ASMVT injury. miR-138-5p targeted to downregulate NLRP3. Knockdown of NLRP3 reversed the inhibition of proliferation, apoptosis, and pyroptosis and the decrease in tight junction proteins caused by suppression of miR-138-5p; however, this effect was later inhibited by overexpressing HMGB1. miR-138-5p inhibited pyroptosis, promoted intestinal epithelial tight junctions and alleviated ASMVT injury-induced intestinal barrier disruption via the NLRP3/HMGB1 axis.
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Affiliation(s)
- Yuejin Li
- The First People’s Hospital of Yunnan Province, The Affiliated Hospital of Kunming University of Science and Technology, Kunming, China
| | - Ping Ling
- The First People’s Hospital of Yunnan Province, The Affiliated Hospital of Kunming University of Science and Technology, Kunming, China
| | - Yu Li
- The First People’s Hospital of Yunnan Province, The Affiliated Hospital of Kunming University of Science and Technology, Kunming, China
| | - Yongzhi Wang
- The First People’s Hospital of Yunnan Province, The Affiliated Hospital of Kunming University of Science and Technology, Kunming, China
| | - Guosan Li
- The First People’s Hospital of Yunnan Province, The Affiliated Hospital of Kunming University of Science and Technology, Kunming, China
| | - Changtao Qiu
- The First People’s Hospital of Yunnan Province, The Affiliated Hospital of Kunming University of Science and Technology, Kunming, China
| | - Jianghui Wang
- The First People’s Hospital of Yunnan Province, The Affiliated Hospital of Kunming University of Science and Technology, Kunming, China
| | - Kunmei Gong
- The First People’s Hospital of Yunnan Province, The Affiliated Hospital of Kunming University of Science and Technology, Kunming, China
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Chen YL, Baker TM, Lee F, Shui B, Lee JC, Tvrdik P, Kotlikoff MI, Sonkusare SK. Calcium Signal Profiles in Vascular Endothelium from Cdh5-GCaMP8 and Cx40-GCaMP2 Mice. J Vasc Res 2021; 58:159-171. [PMID: 33706307 PMCID: PMC8102377 DOI: 10.1159/000514210] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 12/23/2020] [Indexed: 01/04/2023] Open
Abstract
INTRODUCTION Studies in Cx40-GCaMP2 mice, which express calcium biosensor GCaMP2 in the endothelium under connexin 40 promoter, have identified the unique properties of endothelial calcium signals. However, Cx40-GCaMP2 mouse is associated with a narrow dynamic range and lack of signal in the venous endothelium. Recent studies have proposed many GCaMPs (GCaMP5/6/7/8) with improved properties although their performance in endothelium-specific calcium studies is not known. METHODS We characterized a newly developed mouse line that constitutively expresses GCaMP8 in the endothelium under the VE-cadherin (Cdh5-GCaMP8) promoter. Calcium signals through endothelial IP3 receptors and TRP vanilloid 4 (TRPV4) ion channels were recorded in mesenteric arteries (MAs) and veins from Cdh5-GCaMP8 and Cx40-GCaMP2 mice. RESULTS Cdh5-GCaMP8 mice showed lower baseline fluorescence intensity, higher dynamic range, and higher amplitudes of individual calcium signals than Cx40-GCaMP2 mice. Importantly, Cdh5-GCaMP8 mice enabled the first recordings of discrete calcium signals in the intact venous endothelium and revealed striking differences in IP3 receptor and TRPV4 channel calcium signals between MAs and mesenteric veins. CONCLUSION Our findings suggest that Cdh5-GCaMP8 mice represent significant improvements in dynamic range, sensitivity for low-intensity signals, and the ability to record calcium signals in venous endothelium.
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Affiliation(s)
- Yen Lin Chen
- Robert M. Berne Cardiovascular Research Center, University of Virginia, Charlottesville, Virginia, USA
| | - Thomas M Baker
- Robert M. Berne Cardiovascular Research Center, University of Virginia, Charlottesville, Virginia, USA
| | - Frank Lee
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
| | - Bo Shui
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
| | - Jane C Lee
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
| | - Petr Tvrdik
- Departments of Neurosurgery and Neuroscience and Bioengineering, University of Virginia, Charlottesville, Virginia, USA
| | - Michael I Kotlikoff
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
| | - Swapnil K Sonkusare
- Robert M. Berne Cardiovascular Research Center, University of Virginia, Charlottesville, Virginia, USA,
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA,
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Hira T, Sekishita M, Hara H. Blood Sampling From Rat Ileal Mesenteric Vein Revealed a Major Role of Dietary Protein in Meal-Induced GLP-1 Response. Front Endocrinol (Lausanne) 2021; 12:689685. [PMID: 34149624 PMCID: PMC8206781 DOI: 10.3389/fendo.2021.689685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 05/17/2021] [Indexed: 11/29/2022] Open
Abstract
The present study was conducted to examine region-dependent glucagon-like peptide-1 (GLP-1) responses to "meal ingestion" under physiological (conscious and unrestrained) conditions using rats with a catheter inserted into either the portal vein (PV) or the ileal mesenteric vein (ILMV). After recovery from the cannulation surgery, blood samples were collected from either PV or ILMV catheter before and after the voluntary ingestion of test diets. After an AIN-93G standard diet ingestion, GLP-1 concentration was higher in ILMV than in PV, and postprandial responses of peptide-YY (PYY) had similar trend, while that of glucose dependent-insulinotropic polypeptide showed an opposite trend to GLP-1/PYY responses. In a separated experiment, a protein-enriched diet containing casein at 25% wt/wt transiently increased GLP-1 concentration only in ILMV; however, a protein-free diet did not increase GLP-1 concentrations in PV or ILMV. These results indicate that postprandial GLP-1 is immediately released from the distal intestine under physiological conditions, and that dietary protein has a critical role in the enhancement of postprandial GLP-1 response.
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Affiliation(s)
- Tohru Hira
- Research Faculty of Agriculture, Hokkaido University, Sapporo, Japan
- Graduate School of Agriculture, Hokkaido University, Sapporo, Japan
- *Correspondence: Tohru Hira,
| | - Madoka Sekishita
- Graduate School of Agriculture, Hokkaido University, Sapporo, Japan
| | - Hiroshi Hara
- Faculty of Human Life Science, Fuji Women’s University, Ishikari, Japan
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Chies AB, de Oliveira PB, Rossignoli PDS, Baptista RDFF, de Lábio RW, Payão SLM. Prostanoids counterbalance the synergism between endothelin-1 and angiotensin II in mesenteric veins of trained rats. Peptides 2017; 88:67-73. [PMID: 28012855 DOI: 10.1016/j.peptides.2016.12.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Revised: 12/15/2016] [Accepted: 12/20/2016] [Indexed: 11/30/2022]
Abstract
Exercise-induced adaptations of the modulating mechanisms that influence the angiotensin (Ang II) responses assume different features depending on the venous bed. In femoral veins, exercise mobilizes vasodilator prostanoids to cooperate with NO in order to maintain reduced Ang II responses. On the other hand, exercise's influence on the Ang II responses in veins that drain blood from the mesenteric region has been poorly described. Therefore, the present study aimed to identify the effects of a single bout of exercise, as well as exercise training, on the Ang II responses in mesenteric veins. The present study also aimed to investigate the involvement of prostanoids, NO and ET-1 in eventual exercise-induced modifications in these veins. To this end, mesenteric veins taken from resting-sedentary, exercised-sedentary, resting-trained and exercised-trained animals were studied in organ baths. In addition, the mRNA expression of prepro-endothelin-1 (ppET-1), as well as that of the ETA and ETB receptors, were quantified by real-time PCR in these veins. The results show that, either in absence or in presence of L-NAME, the Ang II responses were not different between groups. In the presence of indomethacin, higher Ang II responses were observed in the resting-trained animals than in the resting-sedentary animals. This difference, however, disappeared when L-NAME, BQ-123 or BQ-788 were added during incubation. In addition, no differences in ppET-1, ETA or ETB mRNA expression were observed between groups. Furthermore, in the presence of PD123,319, the Ang II responses in the exercised-sedentary animals were higher than those in the resting-sedentary animals. In conclusion, exercise training mobilizes endothelin-1 (ET-1) to reinforce the Ang II-induced responses mainly through ETA activation. On the other hand, vasodilator prostanoids are mobilized to act in parallel with NO in order to counterbalance the Ang II responses that have been potentiated by ET-1 in these trained animals.
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Pan CS, Liu YH, Liu YY, Zhang Y, He K, Yang XY, Hu BH, Chang X, Wang MX, Wei XH, Fan JY, Wu XM, Han JY. Salvianolic Acid B Ameliorates Lipopolysaccharide-Induced Albumin Leakage from Rat Mesenteric Venules through Src-Regulated Transcelluar Pathway and Paracellular Pathway. PLoS One 2015; 10:e0126640. [PMID: 25992563 PMCID: PMC4438061 DOI: 10.1371/journal.pone.0126640] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Accepted: 04/05/2015] [Indexed: 12/15/2022] Open
Abstract
Lipopolysaccharide (LPS) causes microvascular barrier disruption, leading to albumin leakage from microvessels resulting in a range of disastrous sequels. Salvianolic acid B (SalB) is a major water-soluble component derived from Salvia miltiorrhiza. Previous studies showed its potential to attenuate microvascular barrier dysfunction, but the underlying mechanism is not fully understood. The present study was intended to investigate the impact of SalB on endothelial cell barrier in vivo in rat mesenteric venules as well as in vitro in human umbilical vein endothelial cells (HUVECs), aiming at disclosing the mechanism thereof, particularly the role of Src in its action. Male Wistar rats were challenged by infusion of LPS (2 mg/kg/h) through left femoral vein for 90 min. SalB (5 mg/kg/h) was administrated either simultaneously with LPS or 30 min after LPS infusion through the left jugular vein. Vesicles in venular walls were observed by electron microscopy. HUVECs were incubated with LPS with or without SalB. The expression of Zonula occluden-1 (ZO-1), VE-cadherin, caveolin-1 and Src in HUVECs was assessed by Western blot and confocal microscopy, binding of SalB to Src was measured using Surface Plasmon Resonance and BioLayer Interferometry. Treatment with SalB inhibited albumin leakage from rat mesenteric venules and inhibited the increase of vesicle number in venular endothelial cells induced by LPS. In addition, SalB inhibited the degradation of ZO-1, the phosphorylation and redistribution of VE-cadherin, the expression and phosphorylation of caveolin-1, and phosphoirylation of Src in HUVECs exposed to LPS. Furthermore, SalB was found able to bind to Src. This study demonstrates that protection of SalB against microvascular barrier disruption is a process involving both para- and trans-endothelial cell pathway, and highly suggests Src as the key enzyme for SalB to work.
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Affiliation(s)
- Chun-Shui Pan
- Tasly Microcirculation Research Center, Peking University Health Science Center, Beijing, China
- Key Laboratory of Microcirculation, State Administration of Traditional Chinese Medicine of the People's Republic of China, Beijing, China
- Key Laboratory of Stasis and Phlegm, State Administration of Traditional Chinese Medicine of the People's Republic of China, Beijing, China
| | - Ying-Hua Liu
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Peking University Cancer Hospital& Institute, Beijing, China
| | - Yu-Ying Liu
- Tasly Microcirculation Research Center, Peking University Health Science Center, Beijing, China
- Key Laboratory of Microcirculation, State Administration of Traditional Chinese Medicine of the People's Republic of China, Beijing, China
- Key Laboratory of Stasis and Phlegm, State Administration of Traditional Chinese Medicine of the People's Republic of China, Beijing, China
| | - Yu Zhang
- Department of Integration of Traditional Chinese and Western Medicine, School of Basic Medical Sciences, Peking University, Beijing, China
- Key Laboratory of Microcirculation, State Administration of Traditional Chinese Medicine of the People's Republic of China, Beijing, China
- Key Laboratory of Stasis and Phlegm, State Administration of Traditional Chinese Medicine of the People's Republic of China, Beijing, China
| | - Ke He
- Department of Integration of Traditional Chinese and Western Medicine, School of Basic Medical Sciences, Peking University, Beijing, China
- Key Laboratory of Microcirculation, State Administration of Traditional Chinese Medicine of the People's Republic of China, Beijing, China
- Key Laboratory of Stasis and Phlegm, State Administration of Traditional Chinese Medicine of the People's Republic of China, Beijing, China
| | - Xiao-Yuan Yang
- Department of Integration of Traditional Chinese and Western Medicine, School of Basic Medical Sciences, Peking University, Beijing, China
- Key Laboratory of Microcirculation, State Administration of Traditional Chinese Medicine of the People's Republic of China, Beijing, China
- Key Laboratory of Stasis and Phlegm, State Administration of Traditional Chinese Medicine of the People's Republic of China, Beijing, China
| | - Bai-He Hu
- Tasly Microcirculation Research Center, Peking University Health Science Center, Beijing, China
- Key Laboratory of Microcirculation, State Administration of Traditional Chinese Medicine of the People's Republic of China, Beijing, China
- Key Laboratory of Stasis and Phlegm, State Administration of Traditional Chinese Medicine of the People's Republic of China, Beijing, China
| | - Xin Chang
- Tasly Microcirculation Research Center, Peking University Health Science Center, Beijing, China
- Key Laboratory of Microcirculation, State Administration of Traditional Chinese Medicine of the People's Republic of China, Beijing, China
- Key Laboratory of Stasis and Phlegm, State Administration of Traditional Chinese Medicine of the People's Republic of China, Beijing, China
| | - Ming-Xia Wang
- Tasly Microcirculation Research Center, Peking University Health Science Center, Beijing, China
- Key Laboratory of Microcirculation, State Administration of Traditional Chinese Medicine of the People's Republic of China, Beijing, China
- Key Laboratory of Stasis and Phlegm, State Administration of Traditional Chinese Medicine of the People's Republic of China, Beijing, China
| | - Xiao-Hong Wei
- Tasly Microcirculation Research Center, Peking University Health Science Center, Beijing, China
| | - Jing-Yu Fan
- Tasly Microcirculation Research Center, Peking University Health Science Center, Beijing, China
| | - Xin-Min Wu
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Peking University Cancer Hospital& Institute, Beijing, China
| | - Jing-Yan Han
- Tasly Microcirculation Research Center, Peking University Health Science Center, Beijing, China
- Department of Integration of Traditional Chinese and Western Medicine, School of Basic Medical Sciences, Peking University, Beijing, China
- Key Laboratory of Microcirculation, State Administration of Traditional Chinese Medicine of the People's Republic of China, Beijing, China
- Key Laboratory of Stasis and Phlegm, State Administration of Traditional Chinese Medicine of the People's Republic of China, Beijing, China
- * E-mail:
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Sheng L, Tan W, Hu JP, Chen H, Li Y. [Effect of CYP3A and P-glycoprotein on the absorption of buagafuran in rat intestinal lumen]. Yao Xue Xue Bao 2010; 45:43-48. [PMID: 21351448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The rat single-pass intestinal perfusion model was applied to study the effect of CYP3A and P-glycoprotein on the absorption of buagafuran in lumen of rats. Buagafuran concentrations in intestinal perfusate and blood in vena mesenterica collected at different time points after perfusion were determined by GC-MS. Permeability coefficient of buagafuran was calculated by the equation [P(lumen) = -(Q/2pirl)Ln(C(out)/C(in)) and P(blood) = (deltaM(B)/deltat)/(2pirl<C>)]. The effects of troleandomycin (TAO, CYP3A inhibitor), cyclosporin A (CYP3A/p-glycoprotein inhibitor) on the absorption of buagafuran in lumen were observed. After rat single-pass intestinal perfusion, the cumulative amount of buagafuran in mesenteric vein of rat was 73.4, 82.9, and 98.3 pmol x cm(-2) and were increased 3.9, 4.6, and 5.6 fold by addition of inhibitor of P-gp (LSN335984), CYP3A (TAO) or P-gp and CYP3A (CsA), respectively. Moreover, the metabolized fraction of buagafuran was decreased by 12%, 11% and 21% with inhibitors. The results suggested that the poor bioavailability of buagafuran was mostly due to the interplay of P-gp and CYP3A on the absorption, transport and metabolism of buagafuran in intestine of rats.
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Affiliation(s)
- Li Sheng
- Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
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Scheibe R, Schade M, Grundling M, Pavlovic D, Starke K, Wendt M, Retter S, Murphy M, Suchner U, Spassov A, Gedrange T, Lehmann C. Glutamine and alanyl-glutamine dipeptide reduce mesenteric plasma extravasation, leukocyte adhesion and tumor necrosis factor-α (TNF-α) release during experimental endotoxemia. J Physiol Pharmacol 2009; 60 Suppl 8:19-24. [PMID: 20400787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 10/22/2009] [Accepted: 12/18/2009] [Indexed: 05/29/2023]
Abstract
Glutamine (GLN) appears to be an essential nutrient during organism development and critical illness. The aim of our study was to evaluate the effects of GLN and its generic preparation alanyl-glutamine-dipeptide (DIP) on the microcirculation in endotoxemia in rats and its effects on tonus or aortal rings in vitro. Male Lewis rats (n=40) were separated in 4 groups. Group 1 (CON) served as healthy control group while the other groups received an endotoxin bolus i.v. (5 mg/kg lipopolysaccharide, LPS i.v.). In group 3 (LPS+GLN) 0.75 g/kg-1 GLN i.v. before LPS challenge was administered. In group 4 (LPS+DIP) DIP containing 0.75 g/kg GLN was given. Leukocyte-endothelial interactions and mesenteric plasma extravasation were determined at 0, 1 and 2 hours during the experiment by intravital fluorescence microscopy (IVM). Cytokine release (TNF-alpha, IL-1 beta, IL-6, IL-10) was measured by ELISA. GLN treatment reduced leukocyte adherence (-49.7% vs. LPS group, p<0.05) and plasma extravasation (-12.3% vs. LPS group, p<0.05) significantly during endotoxemia compared to untreated LPS animals. In group 4 (DIP+LPS), a decrease of leukocyte adherence (-56.0%) and mesenteric plasma extravasation (-18.8% vs. LPS group, p<0.05) was also found. TNF-alpha levels were reduced in both GLN and DIP (p<0.05). In vitro experiments demonstrated that glutamine agents could attenuate the response to contracting agents in presence of the vascular endothelium, implying nitric oxide pathway. In vivo, GLN as well as DIP pre-treatment diminish the detrimental impact of endotoxemia on the mesenteric microcirculation and the TNF-alpha release, the effects whose clinical importance should be further examined.
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Affiliation(s)
- R Scheibe
- Department of Anesthesia and Intensive Care Medicine, Ernst Moritz Arndt University, Greifswald, Germany
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Walshe TE, Dole VS, Maharaj AS, Patten IS, Wagner DD, D’Amore PA. Inhibition of VEGF or TGF-{beta} signaling activates endothelium and increases leukocyte rolling. Arterioscler Thromb Vasc Biol 2009; 29:1185-92. [PMID: 19461051 PMCID: PMC2775449 DOI: 10.1161/atvbaha.109.186742] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
OBJECTIVE Motivated by the central roles that vascular endothelial growth factor (VEGF) and transforming growth factor (TGF)-beta play in the assembly and maintenance of the vasculature, we examined the impact of systemic VEGF or TGF-beta signal inhibition on endothelial activation as detected by leukocyte-endothelial interactions. METHODS AND RESULTS VEGF or TGF-beta inhibition, accomplished using adenovirus expression of soluble Flt1 (Ad-sFlt1) or soluble endoglin (Ad-sEng), resulted in a significant increase in the number of leukocytes rolling along the mesenteric venous endothelium and a significant decrease in rolling velocity in Ad-sEng mice. Neutralization of VEGF or TGF-beta resulted in endothelial surface expression of P-selectin and impaired peripheral vasodilatation. Neither inhibition of VEGF nor TGF-beta was associated with platelet or leukocyte activation, as detected by the activation markers platelet P-selectin and the active integrin alphaIIbbetaIII, or by leukocyte expression of L-selectin. Soluble vascular cell adhesion molecule (VCAM)-1 and E-selectin were increased in sEng-expressing mice, indicating higher levels of these adhesion receptors. CONCLUSIONS VEGF or TGF-beta neutralization leads to impaired endothelium-mediated vasodilatation and elevated expression of surface adhesion molecules, resulting in increased leukocyte adhesion. These results indicate an essential role for both VEGF and TGF-beta in maintaining the endothelium in a nonactivated state and have implications for therapeutic approaches that neutralize VEGF or TGF-beta.
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Affiliation(s)
- Tony E. Walshe
- Schepens Eye Research Institute and Harvard Medical School, 20 Staniford Street, Boston, MA 02114
| | - Vandana S. Dole
- Immune Disease Institute, Boston, MA 02115
- Department of Pathology, Harvard Medical School, Boston, MA 02115
| | - Arindel S.R. Maharaj
- Schepens Eye Research Institute and Harvard Medical School, 20 Staniford Street, Boston, MA 02114
| | | | - Denisa D. Wagner
- Immune Disease Institute, Boston, MA 02115
- Department of Pathology, Harvard Medical School, Boston, MA 02115
| | - Patricia A. D’Amore
- Schepens Eye Research Institute and Harvard Medical School, 20 Staniford Street, Boston, MA 02114
- Department of Pathology, Harvard Medical School, Boston, MA 02115
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Zhou L, Yang J, Zhang XY, Liu XQ, Wang GJ. [Effect of phospholipid on absorption of diammonium glycyrrhizinate]. Yao Xue Xue Bao 2008; 43:71-75. [PMID: 18357736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
To investigate the absorption mechanism of diammonium glycyrrhizinate (GL) for oral use in rat intestine as well as the effect of phospholipids on GL and its metabolite glycyrrhetic acid (GA), in situ single pass intestinal perfusion model and the rat single-pass intestinal perfusion with mesenteric cannulation model were used and the concentrations of GL and GA in perfusate and blood were determined by HPLC. The apparent permeability values (Papp) of GA with or without phospholipids are 7.98 and 5.73 cm x min(-1), respectively, whereas the permeability of GL had no significant statistical difference. The results showed that phospholipids can increase the absorption extent and speed of GA. This action can be used in the research and development of the new drugs of the glycyrrhiza.
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Affiliation(s)
- Liang Zhou
- Key Lab of Drug Metabolism and Pharmacokinetics, China Pharmaceutical University, Nanjing 210009, China
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Sanz MJ, Cortijo J, Taha MA, Cerdá-Nicolás M, Schatton E, Burgbacher B, Klar J, Tenor H, Schudt C, Issekutz AC, Hatzelmann A, Morcillo EJ. Roflumilast inhibits leukocyte-endothelial cell interactions, expression of adhesion molecules and microvascular permeability. Br J Pharmacol 2007; 152:481-92. [PMID: 17704822 PMCID: PMC2050829 DOI: 10.1038/sj.bjp.0707428] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND AND PURPOSE The present study addressed the effects of the investigational PDE4 inhibitor roflumilast on leukocyte-endothelial cell interactions and endothelial permeability in vivo and in vitro. EXPERIMENTAL APPROACH In vivo, intravital video-microscopy was used to determine effects of roflumilast p.o. on leukocyte-endothelial cell interactions and microvascular permeability in rat mesenteric venules. In vitro, the effects of roflumilast N-oxide, the active metabolite of roflumilast in humans, and other PDE4 inhibitors on neutrophil adhesion to tumour necrosis factor alpha (TNFalpha)-activated human umbilical vein endothelial cells (HUVEC), E-selectin expression and thrombin-induced endothelial permeability was evaluated. Flow cytometry was used to determine the effect of roflumilast on N-formyl-methionyl-leucyl-phenylalanine (fMLP)-induced CD11b upregulation on human neutrophils. KEY RESULTS In vivo, roflumilast, given 1 h before lipopolysaccharide (LPS), dose-dependently reduced leukocyte-endothelial cell interactions in rat mesenteric postcapillary venules. It also diminished histamine-induced microvascular permeability. Immunohistochemical analyses revealed that roflumilast prevented LPS-induced endothelial P- and E-selectin expression. In vitro, roflumilast N-oxide concentration-dependently suppressed neutrophil adhesion to TNFalpha-activated HUVEC and CD11b expression on fMLP-stimulated neutrophils. It also reduced TNFalpha-induced E-selectin expression on HUVEC, when PDE3 activity was blocked. HUVEC permeability elicited by thrombin was concentration-dependently suppressed by roflumilast N-oxide. While roflumilast N-oxide was as potent as roflumilast at inhibiting stimulated endothelial cell and neutrophil functions, both compounds were significantly more potent than the structurally unrelated PDE4 inhibitors, rolipram or cilomilast. CONCLUSIONS AND IMPLICATIONS These findings further support earlier observations on the inhibition of inflammatory cell influx and protein extravasation by roflumilast in vivo.
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Affiliation(s)
- M-J Sanz
- Department of Pharmacology, University of Valencia Valencia, Spain
- Ciber CB06/06/0027 ‘Respiratory Diseases', Carlos III Health Institute, Spanish Ministry of Health Madrid, Spain
| | - J Cortijo
- Department of Pharmacology, University of Valencia Valencia, Spain
- Ciber CB06/06/0027 ‘Respiratory Diseases', Carlos III Health Institute, Spanish Ministry of Health Madrid, Spain
- Research Foundation, University General Hospital Consortium, University of Valencia Valencia, Spain
| | - M A Taha
- Department of Pharmacology, University of Valencia Valencia, Spain
| | - M Cerdá-Nicolás
- Ciber CB06/06/0027 ‘Respiratory Diseases', Carlos III Health Institute, Spanish Ministry of Health Madrid, Spain
- Department of Pathology, University of Valencia Valencia, Spain
| | - E Schatton
- Department of Biochemistry, Nycomed GmbH Konstanz, Germany
| | - B Burgbacher
- Department of Biochemistry, Nycomed GmbH Konstanz, Germany
| | - J Klar
- Department of Biochemistry, Nycomed GmbH Konstanz, Germany
| | - H Tenor
- Department of Biochemistry, Nycomed GmbH Konstanz, Germany
| | - C Schudt
- Department of Biochemistry, Nycomed GmbH Konstanz, Germany
| | - A C Issekutz
- Division of Immunology, Department of Pediatrics, Dalhousie University Halifax, Nova Scotia, Canada
| | - A Hatzelmann
- Department of Biochemistry, Nycomed GmbH Konstanz, Germany
| | - E J Morcillo
- Department of Pharmacology, University of Valencia Valencia, Spain
- Ciber CB06/06/0027 ‘Respiratory Diseases', Carlos III Health Institute, Spanish Ministry of Health Madrid, Spain
- Clinical Pharmacology Unit, University Clinical Hospital, University of Valencia Valencia, Spain
- Author for correspondence:
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11
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Abstract
1. Although leptin increases sympathetic nerve activity and blood pressure, its direct action on large arterial rings is to cause relaxation. However, it is the small resistance arteries and veins that are important in blood pressure control. The effects of leptin on these small vessels has not been reported previously in the canine and the effect of leptin on the capacitance vessels is not known. 2. In the present study, third- or fourth-order canine mesenteric arteries and veins were isolated and placed in a perfusion myograph and preconstricted with noradrenaline. The responses to graded concentrations of leptin were determined and the role of nitric oxide was assessed by administration of N(G)-nitro-l-arginine methyl ester (l-NAME), a blocker of nitric oxide synthase. 3. Leptin induced dose-related dilatations in both arterial and venous segments. The mean (+/-SEM) maximum increases in the diameter of the arteries and veins were 25.0 +/- 4.8 and 29.9 +/- 2.0% of the initial preconstriction, respectively. Relaxations of both arteries and veins were abolished by l-NAME or by endothelium denudation, although dilatations were still obtained to sodium nitroprusside, a nitric oxide donor. 4. These results indicate that leptin dilates canine small mesenteric arteries and veins by a mechanism involving endothelial release of nitric oxide. This observation may result in a decrease of peripheral resistance and venous return and, hence, counteract the leptin-induced neurally mediated vasoconstriction that has been reported previously.
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Affiliation(s)
- M M J Mohammed
- Department of Physiology, Faculty of Medicine, Jordan University of Science and Technology, Irbid, Jordan
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12
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Zhang H, Zhi L, Moochhala SM, Moore PK, Bhatia M. Endogenous hydrogen sulfide regulates leukocyte trafficking in cecal ligation and puncture-induced sepsis. J Leukoc Biol 2007; 82:894-905. [PMID: 17599903 DOI: 10.1189/jlb.0407237] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Hydrogen sulfide (H(2)S) is recognized increasingly as a proinflammatory mediator in various inflammatory conditions. Here, we have investigated the role of H(2)S in regulating expression of some endothelial adhesion molecules and recruitment of leukocytes to inflamed sites in sepsis. Male Swiss mice were subjected to cecal ligation and puncture (CLP)-induced sepsis and treated with saline (i.p.), DL-propargylglycine (PAG; 50 mg/kg, i.p.), an inhibitor of H(2)S formation or NaHS (10 mg/kg, i.p.), an H(2)S donor. PAG was administered 1 h before or after the induction of sepsis, and NaHS was given at the same time of CLP. Using intravital microcopy, we found that in sepsis, prophylactic and therapeutic administration of PAG reduced leukocyte rolling and adherence significantly in mesenteric venules coupled with decreased mRNA and protein levels of adhesion molecules (ICAM-1, P-selectin, and E-selectin) in lung and liver. In contrast, injection of NaHS up-regulated leukocyte rolling and attachment significantly, as well as tissue levels of adhesion molecules in sepsis. Conversely, normal mice were given NaHS (10 mg/kg, i.p.) to induce lung inflammation, with or without NF-kappaB inhibitor BAY 11-7082 pretreatment. NaHS treatment enhanced the level of adhesion molecules and neutrophil infiltration in lung. These alterations were reversed by pretreatment with BAY 11-7082. Moreover, expression of CXCR2 in neutrophils obtained from H(2)S-treated mice was up-regulated significantly, leading to an obvious elevation in MIP-2-directed migration of neutrophils. Therefore, H(2)S acts as an important endogenous regulator of leukocyte activation and trafficking during an inflammatory response.
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Affiliation(s)
- Huili Zhang
- Department of Pharmacology, Centre for Life Sciences, National University of Singapore, 28 Medical Drive, Singapore 117456
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13
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Ueda K, Kajikawa A, Suzuki Y, Okazaki M, Nakagawa M, Iida S. Blood gas analysis of the jejunum in the supercharge technique: to what degree does circulation improve? Plast Reconstr Surg 2007; 119:1745-1750. [PMID: 17440349 DOI: 10.1097/01.prs.0000246598.99115.47] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND The supercharge technique has become widely prevalent in the field of esophageal reconstruction. Despite the logical advantages with this technique, the actual degree of its effect on the blood circulation is not clear. There may be cases in which the supercharge technique is not necessary for survival of the jejunum. To decide whether or not the supercharge technique is indicated, it is crucial to know how effective it is in improving blood flow to the jejunum. METHODS The effect of the additional vessel anastomosis in the pedicled jejunal transfer was evaluated by blood gas analysis of the venous blood in the mesenteric vein. In 27 patients undergoing pedicled jejunal transfer with additional vessel anastomosis using the internal mammary vessels for reconstruction of the thoracic esophagus, intraoperative blood sampling was performed three times: before anastomosis, after venous anastomosis, and after venous and arterial anastomosis. RESULTS The venous partial pressure of oxygen showed little increase after the venous anastomosis (mean, 115.7 percent; p = 0.0022). In contrast, venous partial pressure of oxygen increased markedly after the arterial and venous anastomosis in most of the patients (mean, 177.8 percent; p < 0.0001). Similarly, venous partial pressure of carbon dioxide, after both anastomoses, decreased to a lower level than before the additional anastomosis in most patients (mean, 93.1 percent; p = 0.035). CONCLUSION The authors conclude that the additional anastomosis of both the artery and the vein is recommended if it is possible.
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Affiliation(s)
- Kazuki Ueda
- Fukushima, Tokyo, and Shizuoka, Japan From the Departments of Plastic and Reconstructive Surgery, Fukushima Medical University and University of Tokyo, and Department of Plastic Surgery, Shizuoka Cancer Center
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14
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Pérez-Rivera AA, Hlavacova A, Rosario-Colón LA, Fink GD, Galligan JJ. Differential contributions of alpha-1 and alpha-2 adrenoceptors to vasoconstriction in mesenteric arteries and veins of normal and hypertensive mice. Vascul Pharmacol 2007; 46:373-82. [PMID: 17329171 PMCID: PMC3549429 DOI: 10.1016/j.vph.2007.01.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2006] [Revised: 10/21/2006] [Accepted: 01/18/2007] [Indexed: 11/19/2022]
Abstract
Mesenteric veins are more sensitive than arteries to the constrictor effects of sympathetic nerve stimulation and alpha-adrenergic receptor agonists. In the present study, we tested the hypothesis that alpha(2)-adrenergic receptors (alpha(2)-ARs) contribute to in vitro agonist-induced constriction in veins but not arteries and that alpha(2)-AR function is down-regulated in mesenteric arteries and veins in deoxycorticosterone acetate-salt (DOCA-salt) hypertension. Norepinephrine (NE) concentration-response curves were similar in SHAM and DOCA-salt arteries and veins indicating that adrenergic reactivity of mesenteric blood vessels is not altered in murine DOCA-salt hypertension in vitro. Veins were 30-fold more sensitive to NE than arteries. The alpha(1)-AR antagonist, prazosin (0.003-0.3 microM), produced concentration-dependent rightward shifts of the NE concentration-response curves in arteries but not veins. The alpha(2)-AR agonists, clonidine and UK-14,304, did not constrict arteries or veins in the absence or presence of indomethacin (10 microM) and nitro-L-arginine (NLA; 100 microM). The alpha(2)-AR antagonists, yohimbine (0.003-0.3 microM) and rauwolscine (0.1 microM) did not affect NE responses in SHAM or DOCA-salt arteries but antagonized NE responses in veins. These data indicate that there are different alpha-AR contractile mechanisms in murine mesenteric arteries and veins. Alpha(1)-ARs, but not alpha(2)-ARs, mediate direct contractile responses in arteries and veins while alpha(2)-ARs contribute indirectly to NE-induced constrictions in veins but not arteries in vitro. There may be direct protein-protein interactions between alpha(1)- and alpha(2)-ARs or between their signaling pathways in veins. This contribution of alpha(2)-ARs may account for the greater sensitivity of veins compared to arteries to the contractile effects of NE.
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MESH Headings
- Adrenergic Antagonists/pharmacology
- Adrenergic alpha-Agonists/pharmacology
- Animals
- Desoxycorticosterone
- Disease Models, Animal
- Dose-Response Relationship, Drug
- Hypertension/chemically induced
- Hypertension/metabolism
- Hypertension/physiopathology
- Male
- Mesenteric Arteries/drug effects
- Mesenteric Arteries/metabolism
- Mesenteric Arteries/physiopathology
- Mesenteric Veins/drug effects
- Mesenteric Veins/metabolism
- Mesenteric Veins/physiopathology
- Mice
- Mice, Inbred C57BL
- Norepinephrine/pharmacology
- Receptors, Adrenergic, alpha-1/drug effects
- Receptors, Adrenergic, alpha-1/metabolism
- Receptors, Adrenergic, alpha-2/drug effects
- Receptors, Adrenergic, alpha-2/metabolism
- Sodium Chloride
- Vasoconstriction/drug effects
- Vasoconstrictor Agents/pharmacology
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Affiliation(s)
- Alex A Pérez-Rivera
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI 48824, USA
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15
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Taback B, Saha S, Hoon DSB. Comparative analysis of mesenteric and peripheral blood circulating tumor DNA in colorectal cancer patients. Ann N Y Acad Sci 2007; 1075:197-203. [PMID: 17108212 DOI: 10.1196/annals.1368.027] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
An increasing number of reports have demonstrated the presence of tumor-specific DNA in cancer patients' plasma/serum. These findings offer the prospective of serologic tumor markers that may aide in early disease detection, predict subclinical disease progression, and monitor treatment responses. However, for patients with colorectal cancer (CRC), there are few reports using this approach, with most revealing poor sensitivity. In contrast to tumors of other organ systems, CRCs drain predominantly via the mesenteric/portal veins (MV) to the liver. We hypothesize that because of this unique relation, tumor DNA may be less abundant in CRC patients' systemic circulation as compared to the mesenteric/portal system. At the time of surgery, paired blood was collected from both the peripheral vein (PV) and MV from 33 CRC patients. DNA was isolated from serum, quantified and assessed for loss of heterozygosity (LOH) using a panel of 11 microsatellite markers corresponding to regions on six chromosomes frequent for LOH in CRC. In addition, 16 samples were assessed for the presence of hypermethylated DNA for tumor suppressor genes: MGMT, P16, RAR-beta2, RASSF1A, and APC. Circulating tumor DNA associated with LOH or methylation was more frequently detected in the MV of patients, 11 (33%) and 6 (38%), as compared to PV, 9 (27%) and 1 (6%), respectively. This study is the first to identify the presence of increased tumor DNA in the direct efferent venous drainage system of CRC and its variation as compared to systemic circulation. The findings provide important evidence supporting the origin of tumor-associated DNA in circulation, which merits consideration when devising blood-based nucleic acid assays for the assessment of CRC.
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Affiliation(s)
- Bret Taback
- Department of Molecular Oncology, John Wayne Cancer Institute, 2200 Santa Monica Blvd, Santa Monica, CA 90404, USA
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16
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Peredo HA, Mayer MA, Rodríguez Fermepín M, Grinspon D, Puyó AM. Oral treatment and in vitro incubation with fructose modify vascular prostanoid production in the rat. ACTA ACUST UNITED AC 2006; 26:15-20. [PMID: 16371062 DOI: 10.1111/j.1474-8673.2005.00354.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
1.-- In the rat, a fructose-enriched diet induces hyperglycaemia, hypertriglyceridaemia, insulin resistance and hypertension; a model which resembles the human metabolic syndrome. 2.-- Prostanoids, metabolites of arachidonic acid, include vasoactive substances synthesized and released from the vascular wall that have been implicated in the increase of peripheral resistance, one of the mechanisms involved in the fructose-induced hypertension. 3.-- The aim of the present study was to: (i) analyse the effects of the in vitro incubation with fructose on the production and release of prostanoids in rat thoracic aorta and in rat mesenteric bed and (ii) compare the effects of incubation with those of the in vivo acute and chronic treatment of rats with fructose and with the combination of both in vivo and in vitro procedures. 4.-- Blood pressure, glycaemia and triglyceridaemia were significantly elevated in both 4- and 22-week fructose-treated groups. Meanwhile, body and heart weight as well as insulinaemia were similar between experimental animals and controls. 5.-- In aortae, 4 weeks of Fructose treatment did not modify the prostanoid pattern release, but in vitro incubation decreased prostacyclin (PGI(2)) production. However, after 22 weeks, fructose treatment and incubation exerted the same effect. 6.-- In mesenteric bed, after 4 weeks, the incubation and the combination of both procedures reduced the release of the vasodilators PGI(2) and PGE(2), while fructose treatment only diminished the PGE(2) release. On the contrary, the production of the vasoconstrictor thromboxane A(2) (TXA(2)) was enhanced by incubation and both the procedures. After 22 weeks, fructose treatment increased PGI(2) release, while it was reduced by incubation. The combination of both did not modify this peripheral resistance when compared with controls. Finally, incubation of tissues from treated rats increased the release of the vasoconstrictors, PGF(2alpha) and TXA(2). 7.-- In conclusion, the mesenteric bed, a resistance vascular bed, seems to be more sensitive than the aorta, a conductance vessel, to the effects of fructose on prostanoid production. This difference could be related to a more relevant role of resistance vessels in the regulation of peripheral resistance and consequently of blood pressure. The observed effects should contribute to a shift in the balance of the release of prostanoid in favour of vasoconstrictor metabolites. This phenomenon could be related to an increase in the peripheral resistance and the mild hypertension observed in the fructose-treated rats.
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Affiliation(s)
- H A Peredo
- Cátedras de Farmacotecnia I, Universidad de Buenos Aires, Junín 956, 1113 Buenos Aires and CONICET, República Argentina
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17
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Morato M, Pinho D, Sousa T, Guimarães S, Moura D, Albino-Teixeira A. Pre- and postjunctional effects of angiotensin II in hypertension due to adenosine receptor blockade. Eur J Pharmacol 2006; 531:209-16. [PMID: 16438958 DOI: 10.1016/j.ejphar.2005.12.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2005] [Revised: 12/02/2005] [Accepted: 12/12/2005] [Indexed: 11/17/2022]
Abstract
Prejunctional facilitation of [3H]noradrenaline release induced by sympathetic nerve stimulation and postjunctional contractile effects of angiotensin II were studied in the mesenteric artery and vein of 1,3-dipropyl-8-sulfophenylxanthine (DPSPX)-hypertensive rats. Male Wistar rats received infusions of saline or DPSPX (90 microg/kg/h) i.p.. Blood pressure was determined by tail-cuff. The prejunctional effect of angiotensin II was similar in artery and vein preparations of control rats and was increased in DPSPX-hypertensive rats. In contrast, the contractile effect of angiotensin II was much more pronounced in the mesenteric vein than in the mesenteric artery of control rats and was markedly reduced in DPSPX-hypertensive rats. We conclude that (1) the increased prejunctional effect of angiotensin II may contribute to, while (2) the decreased contractile effect of angiotensin II may attenuate DPSPX-induced hypertension. This study also supports the hypothesis that pre- and postjunctional angiotensin II receptors are different.
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Affiliation(s)
- Manuela Morato
- Institute of Pharmacology and Therapeutics, Faculty of Medicine and IBMC, University of Porto, Alameda Prof. Hernâni Monteiro, 4200-319 Porto, Portugal
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18
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Galligan JJ, Miller SB, Katki K, Supowit S, DiPette D, Fink GD. Increased substance P content in nerve fibers associated with mesenteric veins from deoxycorticosterone acetate (DOCA)-salt hypertensive rats. ACTA ACUST UNITED AC 2005; 133:97-104. [PMID: 16297989 DOI: 10.1016/j.regpep.2005.09.030] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2005] [Revised: 09/19/2005] [Accepted: 09/20/2005] [Indexed: 11/26/2022]
Abstract
This study examined sensory nerves associated with mesenteric arteries and veins in sham and deoxycorticosterone acetate (DOCA)-salt hypertensive rats. Reactivity of arteries and veins to substances released from sensory nerves was also studied in vitro using computer-assisted video microscopy. Co-localization of substance P (SP) and calcitonin gene-related peptide (CGRP) immunoreactivity (ir) was used to evaluate perivascular sensory nerves. Radioimmunoassay was used to quantify SP- and CGRP-ir content. Immunohistochemical studies revealed a plexus of SP/CGRP-ir nerves associated with arteries and veins. The intensity of SP-ir, but not CGRP-ir labeling was greater in arteries and veins from DOCA-salt compared to sham rats. RIA measurements revealed that the CGRP-ir content of arteries and veins was higher than the SP-ir content but there was a significant increase in SP-ir, but not CGRP-ir, content in arteries and veins from DOCA-salt rats. SP (0.03-1 microM) contracted veins and the NK-3 receptor agonist, senktide, mimicked this effect. There were no differences in SP or senktide reactivity of veins from sham or DOCA-salt rats. SP, but not senktide, relaxed KCl (40 mM) preconstricted arteries. CGRP (0.3 microM), acetylcholine (10 microM) and capsaicin (1 microM) relaxed KCl-preconstricted arteries and veins. The NK-1 receptor agonist, substance P methyl ester relaxed arteries but not veins. These data indicate that DOCA-salt hypertension is associated with upregulation of SP content in perivascular nerves. NK-3 receptors mediate venoconstriction which is unchanged in DOCA-salt hypertension. Increased release of SP from perivenous nerves might contribute to the increased venomotor tone in DOCA-salt hypertension.
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Affiliation(s)
- James J Galligan
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI 48824, USA.
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19
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De Hertogh G, Van Eyken P, Stessens L, Caenepeel P, Geoboes K. Myointimal hyperplasia of mesenteric veins secondary to heterozygous factor V Leiden mutation. Histopathology 2005; 47:322-4. [PMID: 16115236 DOI: 10.1111/j.1365-2559.2005.02095.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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20
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Ghorab MM, Abdel-Salam HM, Abdel-Moate MM. Effects of Glycerides on the Intestinal Absorption of Cyclosporine A Using the In-Situ Mesenteric Vein Cannulated Rat Model. Curr Drug Deliv 2005; 2:289-94. [PMID: 16305431 DOI: 10.2174/1567201054368011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The purpose of this study was to evaluate and compare the effect of glycerides with different fatty acid distributions (e.g. Arlacel 186, Capmul GMO and Captex 350) on Cyclosporine absorption in rat ileum segment using the modified single-pass intestinal perfusion with mesenteric vein cannulation. Drug concentration in the perfusate and blood plasma was analyzed by HPLC; and permeability coefficients were calculated from drug appearance in blood (P(blood)) and disappearance from perfusate (P(lumen)). Particle size was measured using Malvern Zetasaizer 1000HSA. Rheologic properties were measured using Brookfield viscometer. The results show that the average particle sizes after dilution (100 folds) of formulae containing Arlacel 186, Capmul GMO and Captex 350 and containing 0.8 mM CsA were 260+/-35.8, 130+/-11.4 and 37.5+/-6.0 nm, respectively. The polydispersity index was 0.6, 0.7 and 0.108 for formulations with Arlacel 186, Capmul GMO and Captex 350, respectively. CsA permeability coefficients (P(blood)) calculated from drug appearance in the blood in presence of Arlacel 186, Capmul GMO and Captex 350 were 0.3x10(-6), 1.0x10(-6) and 1.7x10(-6) cm2/sec, respectively. Phenol red was used as a water marker to determine net water absorption and secretion. Its constant concentration suggested that formulation did not alter intestinal water flux. From the results we can conclude that degree of glyceride esterification has a potential impact on the average particle size distribution and polydispersity of the formed micelles on dilution, which on turn contribute to the interaction between membrane and drug.
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Affiliation(s)
- Mamdouh M Ghorab
- Department of Pharmaceutics, College of Pharmacy, Suez Canal University, Ismailia, P.O. 41522, Egypt.
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21
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Abstract
Vascular capacitance is reduced by endothelin-1 (ET-1) in deoxycorticosterone (DOCA)-salt hypertensive rats. This may contribute to hypertension development. Because the splanchnic blood vessels (especially veins) are important in determining vascular capacitance, we tested the hypothesis that ET-1 levels in the splanchnic vasculature are elevated in hypertensive DOCA-salt compared with normotensive rats. Tissue ET-1 content was measured by ELISA in aorta, vena cava, superior mesenteric artery and vein, and small mesenteric arteries and veins from normotensive sham-operated (sham) and 4-wk DOCA-salt rats. We also determined ET-1 concentration in aortic and portal venous blood (draining the nonhepatic splanchnic organs) in anesthetized and conscious sham and DOCA-salt rats before and after acute blockade of ETB receptor-mediated plasma clearance of ET-1. Results showed a higher ET-1 content in veins than in arteries of similar size. However, ET-1 content was similar in vessels from sham and DOCA-salt rats, except in aorta and superior mesenteric artery, where ET-1 content was greater in DOCA-salt rats. ET-1 concentration was significantly higher in portal venous than in aortic blood, indicating net nonhepatic splanchnic release (nNHSR) of ET-1. However, nNHSR of ET-1 was similar in sham and DOCA-salt rats. Although nNHSR of ET-1 increased significantly after ETB receptor blockade in sham rats, it was completely unchanged in DOCA-salt rats. These data suggest that, despite the absence of ETB receptor-mediated plasma clearance of ET-1, neither the venous peptide content nor the net release of ET-1 is increased in the splanchnic vasculature of DOCA-salt rats. These results argue against the hypothesis that increased venomotor tone in DOCA-salt hypertension is caused by increased ET-1 concentration around splanchnic venous smooth muscle cells.
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Affiliation(s)
- Hong Wang
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Michigan 48824, USA
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22
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Abstract
cAMP enhances endothelial barrier properties and is protective against various inflammatory mediators both in vivo and in vitro. However, the mechanisms whereby cAMP stabilizes the endothelial barrier are largely unknown. Recently we demonstrated that the Rho family GTPase Rac-1 is required for maintenance of endothelial barrier functions in vivo and in vitro. Therefore, in the present study we investigated the effect of forskolin (5 microM)- and rolipram (10 microM)-induced cAMP increase on reduction of barrier functions in response to Rac-1 inhibition by Clostridium sordellii lethal toxin (LT). Forskolin and rolipram treatment blocked LT (200 ng/ml)-induced hydraulic conductivity (Lp) increase in mesenteric microvessels in vivo. Likewise, LT-induced intercellular gap formation in monolayers of cultured microvascular myocardial endothelial (MyEnd) cells and LT-induced loss of adhesion of vascular endothelial cadherin-coated microbeads were abolished. Inhibition of PKA by myristoylated inhibitor peptide (14-22) of PKA (100 microM) reduced the protective effect of cAMP on LT-induced Lp increase in vivo and gap formation in vitro, indicating that the effect of cAMP on Rac-1 inhibition was PKA dependent. Glucosylation assays demonstrated that cAMP prevents inhibitory Rac-1 glucosylation by LT, indicating that one way that cAMP enhances endothelial barrier functions may be by regulating Rac-1 signaling. Our study suggests that cAMP may provide its well-established protective effects at least in part by regulation of Rho proteins.
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Affiliation(s)
- J Waschke
- Dept. of Physiology and Membrane Biology, School of Medicine, Univ. of California, 1 Shields Ave., Davis, CA 95616, USA
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Zhang X, Wen Y, Xu X, Dong F, Ren J. Agonist-stimulated Ca2+ transport in mesenteric vascular smooth muscle cells of vitamin D3-induced calcium overload rats. Vascul Pharmacol 2003; 40:189-95. [PMID: 14746825 DOI: 10.1016/j.vph.2003.06.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Altered intracellular Ca(2+) homeostasis and accumulated Ca(2+) deposition in arterial walls contribute to the natural arterial aging and aging-related vascular pathologies. To gain further insight into internal relationship between these two factors, a vitamin D(3)-induced vascular Ca(2+) overload rat model was employed. Mesenteric vascular smooth muscle cells (VSMCs) were isolated from both vitamin D(3) and Wistar control rats and were maintained in primary culture for 24 h. Cytosolic and nuclear Ca(2+) ([Ca(2+)](i), [Ca(2+)](n)) in VSMCs were compared between vitamin D(3) and Wistar groups using laser scanning confocal microscopy and Ca(2+)-sensitive-dye Fluo-3. Cytosolic and nuclear Ca(2+) were evaluated under both resting and agonist-stimulated conditions including the voltage-dependent Ca(2+) channel openers BayK8644 and KCl, the inositol-1,4,5-trisphosphate (IP(3))-sensitive Ca(2+) release channel activator IP(3), the ryanodine-sensitive Ca(2+) release channel activator trichloromethane, the sarcoplasmic reticulum Ca(2+) -ATPase inhibitor cyclopiazonic acid, and angiotensin II. Although the levels of [Ca(2+)](n) and [Ca(2+)](i) were comparable between vitamin D(3) and Wistar groups under the resting condition, the increase of [Ca(2+)](n) and [Ca(2+)](i) elicited by various agonists was significantly enhanced in VSMCs from the vitamin D(3) group compared with those from the Wistar group, suggesting abnormality of membrane Ca(2+) gating and intracellular Ca(2+) release under Ca(2+) overload condition. In conclusion, our study indicated that vitamin D(3)-induced vascular Ca(2+) overload may directly interrupt cytosolic and nuclear Ca(2+) homeostasis.
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Affiliation(s)
- Xiaochun Zhang
- Department of Physiology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100005, China
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24
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Pérez-Rivera AA, Fink GD, Galligan JJ. Increased Reactivity of Murine Mesenteric Veins to Adrenergic Agonists: Functional Evidence Supporting Increased α1-Adrenoceptor Reserve in Veins Compared with Arteries. J Pharmacol Exp Ther 2003; 308:350-7. [PMID: 14593081 DOI: 10.1124/jpet.103.056184] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
These studies examined adrenergic reactivity of mesenteric arteries and veins from deoxycorticosterone acetate-salt (DOCA-salt) hypertensive and sham control mice. We measured constrictions in unpressurized arteries and veins by monitoring vessel diameter using computer-assisted video micros-copy in vitro. Veins were more sensitive than arteries to the constricting effects of norepinephrine (NE) and phenylephrine (PE), but the alpha2-agonists clonidine and UK 14,304 [5-bromo-6-(2-imidazolin-2-yl-amino)-quinoxaline] did not constrict arteries or veins. Reactivity was not altered in arteries or veins from DOCA-salt mice. We next investigated the mechanism of increased venous reactivity to NE and PE by studying desensitization to maximum concentrations of NE and PE. Sham arteries desensitized to NE and PE more than DOCA-salt arteries, whereas DOCA-salt and sham veins maintained 80% of the initial NE and PE constriction. To determine whether the increased reactivity and resistance to desensitization in veins was due to a greater alpha-adrenoceptor reserve, vessels were incubated with the alkylating agent phenoxybenzamine (PBZ; 0.3, 3, 10, and 30 nM). The NE-elicited initial constriction was reduced by PBZ (3, 10, and 30 nM) in sham but only by PBZ (30 nM) in DOCA-salt veins. All doses of PBZ blocked NE responses in sham and DOCA-salt arteries. These data suggest that mesenteric veins express more alpha1-adrenoceptors than arteries, accounting for greater reactivity and resistance to desensitization compared with arteries.
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Affiliation(s)
- Alex A Pérez-Rivera
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Michigan 48824, USA.
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Abstract
1. At least two enzymatic activities are proposed to degrade the extracellular ATP: (i) ubiquitously expressed membrane-bound enzymes (ecto-nucleotidases); and (ii) soluble (releasable) nucleotidases that are released during stimulation of sympathetic nerves and break down neuronal ATP. No quantitative data have placed the magnitude of these nucleotidase activities into a physiological perspective of neurovascular control. 2. We studied comparatively the membrane-bound and releasable nucleotidase activities in canine isolated inferior mesenteric arteries and veins using 1,N6-etheno(epsilon)-nucleotides (i.e. epsilon-ATP, epsilon-ADP, epsilon-AMP and epsilon-adenosine) as exogenous substrates. The enzymatic activities were estimated by measuring the disappearance of the epsilon-substrate and appearance of epsilon-products by means of HPLC-fluorescence detection during either stimulation of sympathetic perivascular nerves (releasable activity) or in the absence of nerve stimulation (ecto-nucleotidase activity). 3. Incubation of vascular segments with 50 nmol/L epsilon-ATP for 60 min resulted in a decrease of the epsilon-ATP substrate by 63.5 +/- 4.6 and 91.2 +/- 6.2% in the artery and vein, respectively. In contrast, the decrease of the epsilon-ATP during electrical field stimulation (EFS; 16 Hz, 0.3 msec, 2 min) was 39.8 +/- 4.2% in the artery and 13.1 +/- 7.3% in the vein. Therefore, the mesenteric arteries demonstrate a greater releasable ATPase activity and a weaker ecto-ATPase activity than mesenteric veins. 4. The degradation of epsilon-ADP and epsilon-AMP was similar in both blood vessels under either experimental protocol. The epsilon-adenosine was not significantly degraded in the absence or presence of EFS. 5. These data implicate a differential removal of extracellular ATP as a potential mechanism of serving resistance and capacitance in the splanchnic circulation.
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Affiliation(s)
- Janette Bobalova
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, Nevada, USA
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Tsutsumi K, Li SK, Ghanem AH, Ho NFH, Higuchi WI. A systematic examination of the in vitro Ussing chamber and the in situ single-pass perfusion model systems in rat ileum permeation of model solutes. J Pharm Sci 2003; 92:344-59. [PMID: 12532384 DOI: 10.1002/jps.10278] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
In situ and in vitro intestinal absorption in the rat ileum was systematically studied and mechanistically quantified in terms of permeability coefficients (P) of a series of [(3)H]steroids as model transcellular permeants, [(3)H]taurocholate utilizing the active membrane transport systems to define the aqueous boundary layer (ABL), and [(14)C]urea and [(14)C]mannitol as pore-hindered paracellular diffusants. In situ single-pass perfusion experiments were performed in isolated ileal segments and blood samples were collected from the cannulated mesenteric vein. For the in vitro experiments, an excised, serosal and muscular layer-removed, ileal tissue was mounted in the Ussing chamber diffusion cells. In situ and in vitro P values versus logarithm of the partition coefficient in n-octanol/water (log K) of the steroids were characterized by a sigmoidal-shaped curve in which plateau values were attained for the highly lipophilic steroids with log K greater, similar 2.5. The in situ and in vitro transport barriers in series were viewed as ABL/mucosal epithelium and ABL/mucosal epithelium/submucosal tissue, respectively. Within this framework and the use of experimental strategies and theoretical reasoning, the transport barriers of the steroids were quantitatively delineated and the rate-determining barriers identified. In the plateau region, the analyses indicate that the in situ absorption of the lipophilic steroids was essentially ABL controlled, whereas the in vitro absorption was about equally controlled by diffusion across the ABL and submucosal tissue. The in situ and in vitro pore radii of the paracellular route were 7.2 and 9.2 A, respectively, and the difference was likely the result of perturbation of the tight junctions during the in vitro preparation of the ileal tissue.
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Affiliation(s)
- Keiko Tsutsumi
- Department of Pharmaceutics and Pharmaceutical Chemistry, University of Utah, 30 South 2000 East, Salt Lake City, Utah 84112, USA
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Gunsilius E, Tschmelitsch J, Eberwein M, Schwelberger H, Spizzo G, Kähler CM, Stockhammer G, Lang A, Petzer AL, Gastl G. In vivo release of vascular endothelial growth factor from colorectal carcinomas. Oncology 2002; 62:313-7. [PMID: 12138238 DOI: 10.1159/000065062] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The formation of new blood vessels is essential for the growth of malignant tumors and their hematogenic spread. Tumor-induced neoangiogenesis occurs through sprouting of preexisting vessels. An alternative mechanism might be the recruitment of bone marrow-derived endothelial cells, or their precursors, to the tumor site by the release of vascular endothelial growth factor (VEGF) from cancer cells, i.e., tumor-induced postnatal vasculogenesis. To investigate if a significant amount of VEGF is released from malignant tumors in vivo, thus potentially mobilizing endothelial precursor cells (EPC) from the bone marrow, we measured plasma levels of soluble VEGF obtained from tumor-draining mesenteric veins (VEGF-M) during surgery and, simultaneously, in venous blood obtained distant from the tumor (VEGF-P). This analysis was performed in 29 patients with colorectal carcinoma. VEGF-M levels were substantially higher in patients with distant metastases (208 +/- 61 pg/ml) compared to patients with nonmetastatic disease (99 +/- 72 pg/ml, p = 0.003). Also, in patients with aggressive disease, i.e., histologically undifferentiated (G3) tumors, higher levels of VEGF-M were measured than in patients with tumors of lower histologic grading (196 +/- 46 vs. 107 +/- 80 pg/ml, p = 0.01). In conclusion, the release of significant amounts of soluble VEGF in vivo from clinically and/or histologically aggressive tumors might reflect their high angiogenic or vasculogenic potential, probably leading to the recruitment of EPC from the bone marrow.
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Abstract
Acute systemic hypoxia produces rapid leukocyte adherence in the rat mesenteric microcirculation, although the underlying mechanisms are not fully known. Hypoxia is known to increase reactive oxygen species (ROS) generation, which could result in formation of the lipid inflammatory mediator leukotriene B(4) (LTB(4)). The goal of this study was to examine the role of LTB(4) in hypoxia-induced microvascular alterations. Using intravital microscopy, we determined the effect of the LTB(4) antagonist, LTB(4)-dimethyl amide (LTB(4)-DMA), on ROS generation and leukocyte adherence in mesenteric venules during hypoxia. Exogenous LTB(4) increased ROS generation to 144 +/- 8% compared with control values and also promoted leukocyte adherence. These responses to LTB(4) were blocked by pretreating the mesentery with LTB(4)-DMA. Leukopenia did not significantly attenuate the LTB(4)-induced increase in ROS generation (142 +/- 12.1%). LTB(4)-DMA substantially, though not completely, reduced hypoxia-induced ROS generation from 66 +/- 18% to 11 +/- 4% above control values. Hypoxia-induced leukocyte adherence was significantly attenuated by LTB(4)-DMA. Our results support a role for LTB(4) in the mechanism of hypoxia-induced ROS generation and leukocyte adherence in the rat mesenteric microcirculation.
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Affiliation(s)
- D R Steiner
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, Kansas 66160, USA
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Osanai T, Akutsu N, Fujita N, Nakano T, Takahashi K, Guan W, Okumura K. Cross talk between prostacyclin and nitric oxide under shear in smooth muscle cell: role in monocyte adhesion. Am J Physiol Heart Circ Physiol 2001; 281:H177-82. [PMID: 11406483 DOI: 10.1152/ajpheart.2001.281.1.h177] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We tested the hypothesis that at sites of vascular damage, vessel homeostasis is maintained through the cross talk of shear-induced production of prostacyclin and nitric oxide (NO) in vascular smooth muscle cells (VSMC). Confluent A7r5 cells derived from rat aortic VSMC and mesenteric VSMC were exposed to shear stress at 15 dyn/cm(2) for 90 min with the use of a cone-plate device, and productions of prostacyclin and NO were examined. Shear stress increased cumulative production of prostacyclin by 3- to 3.5-fold and that of NO by 6- to 7.5-fold. Western blot analysis showed that inducible NO synthase protein was expressed after shear stress in both types of VSMC. Inhibition of NO synthase enhanced the shear-induced production of prostacyclin from 40 to 60%. Shear-induced production of NO was suppressed by 70% after treatment with 10(-4) M of indomethacin. A7r5 cells adhesiveness for monocytes was suppressed by 50% after shear stress. This suppression was abolished by pretreatment with 10(-4) M of indomethacin, whereas inhibition of NO synthase only minimally inhibited it. We conclude that there is a cross talk of shear-induced production of prostacyclin and NO in VSMC. At sites of vascular damage, prostacyclin synthesis may prevent monocyte adhesiveness for VSMC through the concomitant enhancement of NO production.
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Affiliation(s)
- T Osanai
- Second Department of Internal Medicine, Hirosaki University School of Medicine, Hirosaki, 036-8562 Japan.
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Peredo HA. Prostanoid release and constrictor responses to noradrenaline in the rat mesenteric vascular bed in non-insulin-dependent diabetes mellitus. J Auton Pharmacol 2001; 21:131-7. [PMID: 11844020 DOI: 10.1046/j.1365-2680.2001.00216.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
1. The administration of streptozotocin (STZ) to 2-day old rats induced a non-insulin-dependent diabetes mellitus (NIDDM)-like state, with mild hyperglycaemia and no alterations in body weight at the adult age. 2. In the isolated and perfused mesenteric vascular bed of NIDDM animals, the constrictor responses to either noradrenaline (NA) or potassium chloride (KCl) were not modified as compared with age-matched non-diabetic controls. 3. The reduction in NA contractions induced by the cyclooxygenase inhibitor, 10 microM indomethacin in the control group was absent in the NIDDM rats. 4. The increase in the NA-induced contractions caused by endothelium removal was suppressed by indomethacin in the controls but not in the NIDDM group. 5. The prostanoid release from the mesenteric vascular beds of NIDDM rats was markedly reduced as compared with non-diabetic controls. Noradrenaline increased production of the constrictor prostaglandin (PG) F2alpha in control but not in NIDDM rats. 6. In summary, these results show that in STZ-induced NIDDM rats, there is an impairment of the prostanoid production, as well as a suppression of the role of prostanoids in the contractile effects of NA in the mesenteric vascular bed. These alterations are more severe than those previously observed in a model of insulin-dependent diabetes mellitus (IDDM), in which hyperglycaemia and reduction of body weight were more marked. The conclusion is that, in these models of diabetes and in the preparation studied, vascular alterations and modifications of glycaemia and body weight are not closely related.
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Affiliation(s)
- H A Peredo
- Instituto de Investigaciones Farmacológicas, CONICET, Buenos Aires, Argentina
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Bobalova J, Mutafova-Yambolieva VN. Co-release of endogenous ATP and noradrenaline from guinea-pig mesenteric veins exceeds co-release from mesenteric arteries. Clin Exp Pharmacol Physiol 2001; 28:397-401. [PMID: 11380513 DOI: 10.1046/j.1440-1681.2001.03460.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
1. The present study was designed to compare the overflow of sympathetic neurotransmitters of guinea-pig inferior mesenteric artery and mesenteric vein evoked by electrical field stimulation (EFS) with special emphasis on the simultaneous release of ATP and noradrenaline (NA). The stimulation-evoked overflow of ADP, AMP and adenosine was also evaluated. 2. Endothelium-denuded segments of inferior mesenteric arteries or veins were superfused in a small volume (200 microL)-chamber for EFS and subsequent detection of NA (HPLC- electrochemical detection) and adenine nucleotides and adenosine (HPLC-fluorescence detection) in samples of the superfusate. 3. Both arteries and veins responded to EFS (15 V, 4-16 Hz, 0.3 msec for 60 s) with overflow of ATP and NA in a tetrodotoxin (1 micromol/L)- and guanethidine (10 micromol/L)-sensitive manner. The EFS-evoked overflow of NA in veins exceeded the overflow of NA in arteries at all frequencies of stimulation, whereas the EFS-evoked overflow of ATP, ADP and AMP in veins exceeded the overflow of adenine nucleotides in arteries at 4 and 8 Hz but not at 16 Hz stimulation. The EFS-evoked overflow of adenosine was similar in arteries and veins. 4. Activation of alpha1-adrenoceptors with methoxamine (10 micromol/L) did not produce overflow of ATP. 5. Blockade of alpha1/alpha2-adrenoceptors with phentolamine (1 micromol/L) did not affect EFS-evoked overflow of ATP, ADP, AMP and adenosine. 6. It is concluded that overflow of ATP and NA from sympathetic nerves may constitute an effective mechanism in the complex balance between capacitance and resistance in splanchnic circulation.
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Affiliation(s)
- J Bobalova
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, Nevada, USA
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Bobalova J, Mutafova-Yambolieva VN. Presynaptic alpha2-adrenoceptor-mediated modulation of adenosine 5' triphosphate and noradrenaline corelease: differences in canine mesenteric artery and vein. J Auton Pharmacol 2001; 21:47-55. [PMID: 11422578 DOI: 10.1046/j.1365-2680.2001.00207.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
1. The modulatory effects of agonists and antagonists of prejunctional alpha2-adrenoceptors on the electrical field stimulation (EFS, 0.3 ms, 12 V)-induced release of endogenous noradrenaline (NA) and the cotransmitter adenosine 5' triphosphate (ATP) were measured in endothelium-denuded segments of canine inferior mesenteric artery and compared with effects in mesenteric vein. The overflow of NA and ATP was evoked by long-duration (2 min) EFS at low frequency (4 Hz) and high frequency (16 Hz) of stimulation and was analysed using HPLC techniques with electrochemical detection and fluorescence detection, respectively. 2. The EFS-evoked overflow of both NA and ATP was significantly reduced by tetrodotoxin (1 microM) and guanethidine (10 microM) in the artery and vein. Desipramine (10 microM), a blocker of neuronal uptake of NA, increased the EFS (4 and 16 Hz)-evoked overflow of NA in both artery and vein. EFS-evoked overflow of NA in vein exceeded the NA overflow in artery at both 4 and 16 Hz in control preparations as well as in the presence of desipramine. However, the EFS-evoked overflow of ATP was equal in the artery and vein. 3. Stimulation of alpha2-adrenoceptors with clonidine (0.1 microM) and oxymethazoline (0.3 microM) reduced the EFS evoked overflow of NA in both artery and vein at 4 Hz, whereas the NA overflow at 16 Hz remained unchanged in both blood vessels. The overflow of ATP as well as of ADP (and hence ATP:ADP ratio) was unaffected by the alpha2-adrenoceptor agonists in the artery and vein. 4. In artery, blockade of alpha2-adrenoceptors with yohimbine at a concentration of 0.1 microM caused no effect on the NA overflow neither at 4 Hz nor at 16 Hz of EFS. Yohimbine at a concentration of 1 microM increased the overflow of NA at 4 Hz but not 16 Hz of EFS. In vein, however, yohimbine (0.1 and 1 microM) increased NA overflow at both 4 and 16 Hz of stimulation. Idazoxan (1 microM) increased the NA overflow in artery only at 4 Hz, whereas in vein idazoxan increased the NA overflow at both 4 and 16 Hz. No changes of EFS-evoked ATP overflow were observed in the presence of 0.1 microM yohimbine in both artery and vein. Greater concentration of yohimbine (i.e. 1 microM) increased the overflow of ATP in both the artery and vein only at 4 Hz EFS. Idazoxan (1 microM) enhanced the ATP overflow only at 16 Hz in vein. The overflow of ADP was affected by both yohimbine and idazoxan in a similar manner to the ATP overflow so that the ATP:ADP ratios were not changed. 5. In conclusion, sympathetic nerves in both mesenteric arteries and veins appear to release ATP along with NA. Release of NA in veins exceeds release of NA in arteries, whereas both the canine artery and vein release equal amount of ATP. At long-duration nerve stimulation (as might occur during stress) the alpha2-adrenoceptors appear to rather modulate release of NA than release of the cotransmitter ATP. The prejunctional autoinhibition of NA release is more effective at lower frequencies of nerve stimulation. The alpha2-adrenoceptor-mediated neuromodulation plays a greater role in veins than arteries. Quantitative differences in alpha2-adrenoceptor-mediated neuromodulation in the arteries and veins may participate to differing contributions of mesenteric blood vessels to the control of blood flow and volume distribution in splanchnic circulation.
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Affiliation(s)
- J Bobalova
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, NV 89557-0046, USA
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Galligan JJ, Hess MC, Miller SB, Fink GD. Differential localization of P2 receptor subtypes in mesenteric arteries and veins of normotensive and hypertensive rats. J Pharmacol Exp Ther 2001; 296:478-85. [PMID: 11160634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023] Open
Abstract
ATP acts at P2 receptors to contract blood vessels and reactivity to vasoconstrictor agents is often altered in hypertension. This study was designed to identify P2 receptors in mesenteric arteries and veins and to determine whether ATP reactivity is altered in deoxycorticosterone acetate (DOCA)-salt hypertensive rats. Computer-assisted video microscopy was used to measure vessel diameter in vitro. ATP was a more potent constrictor of veins (EC(50) = 2.7 microM) than arteries (EC(50) = 196 microM) from normotensive rats; there was no change in ATP reactivity in vessels from DOCA-salt rats. The P2X1 receptor agonist alpha,beta-methylene ATP (alpha,beta-MeATP, 0.03-3 microM) contracted arteries but not veins. ATP-induced contractions in arteries were blocked by alpha,beta-MeATP (3 microM) desensitization. 2-Methylthio-ATP (0.1-10 microM), an agonist that can act at P2Y1 receptors, did not contract arteries or veins, whereas UTP, an agonist at rat P2Y2/P2Y4 receptors, contracted veins (EC(50) = 15 microM) and arteries (EC(50) = 24 microM). UTP-induced contractions of veins cross-desensitized with ATP, whereas UTP-induced contractions in arteries were unaffected by alpha,beta-MeATP-desensitization. The P2X/P2Y1 receptor antagonist pyridoxal-phosphate-6-azophenyl-2',4-disulfonic acid blocked ATP-induced contractions of arteries (IC(50) = 4.8 microM) but not veins. Suramin, an antagonist that blocks P2Y2 receptors, partly inhibited ATP- and UTP-induced contractions of veins. Immunohistochemical studies revealed P2X1 receptor immunoreactivity in arteries but not veins. These data indicate that mesenteric vascular reactivity to ATP is not altered in DOCA-salt hypertension. ATP acts at P2X1 and P2Y2 receptors to contract mesenteric arteries and veins, respectively, whereas in arteries UTP acts at an unidentified P2 receptor.
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Affiliation(s)
- J J Galligan
- Department of Pharmacology and Toxicology and the Neuroscience Program, Michigan State University, East Lansing, Michigan 48824, USA.
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Okudaira N, Tatebayashi T, Speirs GC, Komiya I, Sugiyama Y. A study of the intestinal absorption of an ester-type prodrug, ME3229, in rats: active efflux transport as a cause of poor bioavailability of the active drug. J Pharmacol Exp Ther 2000; 294:580-7. [PMID: 10900235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023] Open
Abstract
The intestinal absorption of a prodrug is affected by a number of factors, such as its membrane permeability, stability in the gut lumen, and conversion to the parent drug in enterocytes. We evaluated the absorption of ME3229, an ester-type prodrug of a hydrophilic glycoprotein IIb/IIIa antagonist. Although the octanol/water distribution coefficient and permeability across a Caco-2 cell monolayer of ME3229 was high enough for us to expect good oral absorption, less than 10% of the dose was absorbed in rats. To clarify this unexpected outcome, we evaluated the rate of its disappearance from the gut lumen (V1), its degradation in the gut lumen (V(deg)), uptake into enterocytes (V(uptake)), and appearance in the mesenteric vein (V2) by using a single-pass perfusion technique in combination with an in vitro metabolism study. Our data suggested that ME3229 crossed the apical membrane and was taken up into enterocytes at a rate compatible with its lipophilicity, but that only a small fraction of the metabolites formed in enterocytes reached the mesenteric vein, primarily attributable to efflux into the intestinal lumen. Transport of the main metabolite across rat intestinal tissue mounted on an Ussing chamber suggested that an active efflux system pumped out any ionic metabolite(s) present.
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Affiliation(s)
- N Okudaira
- Pharmaceutical Research Center, Meiji Seika Kaisha, Ltd., Yokohama, Japan.
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Hagiwara T, Lee CI, Okabe E. Differential sensitivity to hydroxyl radicals of pre- and postjunctional neurovascular transmission in the isolated canine mesenteric vein. Neuropharmacology 2000; 39:1662-72. [PMID: 10854911 DOI: 10.1016/s0028-3908(99)00240-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
In some pathophysiological conditions, the first target of reactive oxygen intermediates is the vascular system. Superoxide anions, when generated in the vascular circulation, may then escape into the extracellular space via an anion channel and, following dismutation to hydrogen peroxide (H(2)O(2)), form hydroxyl radicals (HO(*)). In an attempt to understand the role of HO(*) in the regulation of transmission at the sympathetic neurovascular junction, the effect of HO(*) at nerve terminals was examined by measuring the amount of noradrenaline (NA) released from isolated, spirally cut, superfused canine mesenteric vein during basal and electrical stimulation (ES; 5Hz, 2ms, 9V); tension development evoked by ES was also recorded simultaneously. HO(*) was generated from Fenton's reagent (1. 5x10(-4)M H(2)O(2) plus 10(-4)M FeSO(4)); generation of HO(*) from H(2)O(2)/FeSO(4) in the superfusate was monitored by electron spin resonance spectroscopy using the spin-trap 5, 5-dimethyl-1-pyrroline-N-oxide throughout the experimental time course. Exposure to HO(*) of the helical strips produced an irreversible decrease in tension development evoked by ES with no effect on NA release, suggesting that the observed effect is elicited postjunctionally. The susceptibility of the processes of NA-mediated contraction to HO(*) may differ greatly from that of the NA release mechanism at the prejunctional site. Exposure of the strip preparation to HO(*) leads to a substantial stimulation of basal release of NA without affecting ES-evoked NA release, possibly due to enhanced non-exocytotic Ca(2+)-independent release elicited by HO(*). A direct demonstration of this concept was obtained by showing a significant increase in the basal response of NA release in Ca(2+)-free solution. The major conclusion of the present study is that HO(*) can damage NA-mediated contraction of the vascular preparations at the postjunctional site, and may selectively induce a non-exocytotic release of NA from the prejunctional site of sympathetic neurotransmission.
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Affiliation(s)
- T Hagiwara
- Department of Pharmacology and ESR Laboratory, Kanagawa Dental College, Yokosuka, 283-0003, Kanagawa, Japan
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Abstract
1. We have investigated the effects of varying flow velocity (U) upon permeability to potassium ions (PK) of single perfused mesenteric venules in anaesthetised rats. PK was estimated using a development of the single bolus microperfusion technique at chosen flow velocities in the range of 300 to 6000 microm s-1. 2. In an initial study on 12 vessels, there was a strong positive correlation between PK and U. This was described by the relation: PK = 0.0053U + 8.86, where PK and U are both expressed in micrometres per second (microm s-1). 3. The addition of the nitric oxide (NO) synthase inhibitors (20 micromol l-1) N G-monomethyl-L-arginine (L-NMMA) and N G-nitro L-arginine (L-NNA) to the superfusate abolished the positive correlation between PK and U. The addition of D-NNA (20 micromol l-1) did not change the relation between PK and U where the median value for the slope of the relation was 57.7 (+/- 58.7 interquartile (IQR)) x 10-4 (n = 4). The addition of L-arginine (200 micromol l-1) restored the relation between PK and U where the slope of the relation was increased from 3.9 (+/- 16.3 IQR) x 10-4 to 69.2 (+/- 13.5 IQR) x 10-4 (n = 7). 4. The addition of the guanylate cyclase inhibitor LY83583 (10 micromol l-1) abolished the positive correlation between PK and U (n = 6). 5. Our data suggest that the flow modulates the potassium permeability through the walls of single perfused rat mesenteric venules via a NO-cGMP-dependent process.
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Affiliation(s)
- M Kajimura
- Section of Cellular & Integrative Biology, Division of Biomedical Sciences, Imperial College School of Medicine, South Kensington, London, UK
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Abstract
To investigate relationships between the distribution of endothelin (ET) receptor expression and histopathology of heart and blood vessels, we developed a method of nonradioactive in situ hybridization in paraffin sections. Rat mesenteric bed, rat heart, and human uterine artery were fixed in formalin and embedded in paraffin ETA and ETB receptor cDNAs were subcloned into plasmid vectors for synthesis of sense and anti-sense probes. Digoxigenin (DIG)-UTP was incorporated into every twentieth to twenty-fifth nucleotide of the newly transcribed cRNA. mRNA was detected in situ using an anti-DIG alkaline phosphatase antibody and an alkaline phosphatase substrate. In blood vessels, ETA receptor mRNA was localized to the medial smooth muscle layer and ETB receptor mRNA to the endothelial and adventitial layers. Hearts from rats that had undergone coronary artery ligation for induction of CHF showed intense staining for ETB receptor mRNA in the scarred and infarcted zone of the left ventricle. This method provides a suitable alternative to radioisotope-labeled probes for detection of ET receptor mRNA. It allows better preservation of tissues, shorter detection time, and improved morphology for microscopic analysis.
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Affiliation(s)
- P E McEwan
- Department of Pharmacology, University of Edinburgh, Scotland
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Abstract
The alpha-adrenergic receptors (alpha-ARs) in canine mesenteric vein (DMV) were studied by using nonselective agonists and selective antagonists in functional studies and in ligand binding to classify the subtypes present. Based on functional studies of phenylephrine (PE)-induced contractions and ligand-binding interactions of [3H]-prazosin with prazosin (PR), WB 4101 (WB), 5-methylurapidil (5-MU), BMY 7378, and SK&F 105854, and pretreatment with chloroethylclonidine (CEC), DMV alpha1-ARs resembled the alpha1D subtype. However, the affinity of PR assessed in functional and ligand-binding studies was less (pK(B,D,i) < or = 9) than expected from previous characterization of cloned rat or human alpha1-AR (pKi > or = 10). Interactions with 5-MU, BMY 7378, or SK&F 105854 suggested the presence of some alpha1-ARs that were not typical of alpha1D-AR and that binding and functional interactions did not yield corresponding results. PR binding was abolished by treatment with CEC, contractile responses to PE were reduced in Emax, and the concentration-effect curve shifted to the left, as previously reported. DMVs contracted in response to alpha2-AR agonists and were studied when contractions were potentiated by increasing extracellular KCl to 20 mM. Rauwolscine (RAU) had K(B) values at these sites consistent with K(D) values in binding studies. CEC had no effect on RAU binding in DMV. Ligand-binding studies to [3H]-RAU sites did not reveal a clear identification of subtype, but these alpha2-ARs were clearly not alpha2B-ARs. We conclude that canine mesenteric vein contains alpha1D-like ARs, but with significant differences, and an unclassifiable alpha2-AR. There may also be a smaller population of other, not alpha1D-like ARs, receptors, mediating responses to PE and binding of prazosin.
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MESH Headings
- Adrenergic alpha-Agonists/pharmacology
- Adrenergic alpha-Antagonists/pharmacology
- Animals
- Binding, Competitive
- Clonidine/administration & dosage
- Clonidine/analogs & derivatives
- Dogs
- Female
- Male
- Mesenteric Veins/drug effects
- Mesenteric Veins/metabolism
- Muscle Contraction/drug effects
- Muscle, Smooth, Vascular/drug effects
- Phenylephrine/administration & dosage
- Piperazines/metabolism
- Piperazines/pharmacology
- Prazosin/metabolism
- Receptors, Adrenergic, alpha/drug effects
- Receptors, Adrenergic, alpha/metabolism
- Receptors, Adrenergic, alpha-1/drug effects
- Receptors, Adrenergic, alpha-1/metabolism
- Receptors, Adrenergic, alpha-2/drug effects
- Receptors, Adrenergic, alpha-2/metabolism
- Yohimbine/metabolism
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Affiliation(s)
- E E Daniel
- Department of Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
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39
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Peredo HA, Feleder EC, Adler-Graschinsky E. Differential effects of acetylcholine and bradykinin on prostanoid release from the rat mesenteric bed: role of endothelium and of nitric oxide. Prostaglandins Leukot Essent Fatty Acids 1997; 56:253-8. [PMID: 9150369 DOI: 10.1016/s0952-3278(97)90567-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The roles of nitric oxide and of endothelium in the effects of the vasorelaxing agents acetylcholine and bradykinin on the production of prostanoids was studied in the isolated and perfused mesenteric vascular bed of the rat. Prostanoids were measured in the perfusate by high-performance liquid chromatography (HPLC). In the intact vascular bed, 1 microM bradykinin increased the release of 6-keto-prostaglandinF(1alpha) (stable metabolite of prostacyclin) and of prostaglandin E2 and 10 microM acetylcholine stimulated the efflux of prostacyclin only. In the de-endothelialized vascular bed, bradykinin increased the release of prostacyclin whereas acetylcholine increased the efflux of thromboxane. The inhibition of nitric oxide synthesis with 100 microM N(G)-nitro-L-arginine methyl ester prevented the effect of bradykinin but did not modify the effects of acetylcholine on prostanoid release. In addition, 100 microM L-arginine reversed the inhibitory effect of N(G)-nitro L-arginine methyl ester on bradykinin-stimulated prostaglandin production. It is concluded that acetylcholine and bradykinin stimulate prostanoid release in the rat mesenteric vascular bed with different patterns and through different mechanisms.
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Affiliation(s)
- H A Peredo
- Instituto de Investigaciones Farmacológicas (ININFA, CONICET), Buenos Aires, Argentina
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40
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Cirino G, Calignano A, Andriuoli G, Sorrentino L, Pinto A. Fluoroaluminate induces rapid release of endothelin-1 in the isolated perfused arterial and venous vessels of the rat mesentery. Gen Pharmacol 1997; 28:459-62. [PMID: 9068991 DOI: 10.1016/s0306-3623(96)00153-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
1. Endothelin-1 (ET-1) production from endothelial cells is generally believed to be a process that happens over the course of hours. 2. When fluoroaluminate (AIF-4) was infused in the isolated perfused arterial and venous vessels of the rat mesentery there was an increase in perfusion pressure on both sides. 3. Treatment of mesentery with the endothelin receptor antagonists FR 139317 (ETA receptor selective) or PD 145065 (ETA-ETB receptor nonselective) caused inhibition on both the arterial and venous sides, suggesting that response is mediated predominantly by endothelin-1 through ETA receptors. 4. Endothelial denudation attenuated changes in perfusion pressure of mesenteric circulation generated by fluoroaluminate, but not those caused by exogenously added PGF2 alpha. 5. Our data demonstrate that there is an immediate release of endothelin-1 following fluoroaluminate infusion which could be partially mediated by activation of phospholipase C.
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Daniel EE, Low AM, Gaspar V, Lu-Chao H, Green J, Akrong J, Duerksen S, Soyka C, Chen CK, Boyd J, Kwan CY. Unusual alpha-adrenoceptor subtype in canine saphenous vein: comparison to mesenteric vein. Br J Pharmacol 1996; 117:1535-43. [PMID: 8730751 PMCID: PMC1909456 DOI: 10.1111/j.1476-5381.1996.tb15318.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
1. We investigated the nature of the adrenoceptors in the dog saphenous vein (DSV) and dog mesenteric vein (DMV) to determine the nature of the unexpected interactions of phenylephrine and methoxamine with rauwolscine in the DSV, i.e. the ability of the putative alpha 2-adrenoceptor antagonist to inhibit competitively contractions to these alpha 1-agonists. Radioligand binding studies were performed in parallel with contractility studies. 2. Functionally, in the DSV, phenylephrine and methoxamine-induced, contractions were antagonized by rauwolscine with Schild slopes of -0.52 and -0.46, respectively and apparent pA2 values of 8.5 and 9.2, respectively. Such antagonism was not observed in the DMV. In the DSV, prazosin competes for [3H]-rauwolscine binding sites with a high and a low affinity binding site (Ki of 1.49 +/- 0.65 and 94.7 +/- 51 microM, n = 6, respectively). 3. Pretreatment with 100 microM chloroethylclonidine (CEC) for 15 min abolished [3H]-prazosin binding in microsomes from both veins and reduced binding (Bmax) of [3H]-rauwolscine in microsomes by 55.1 +/- 0.8% (n = 3) in the DSV but did not affect the Bmax in the DMV. CEC pretreatment in the venular rings denuded of endothelium caused persistent contraction in the DSV but not in the DMV. In the DSV, CEC appeared to interact with a single [3H]-rauwolscine binding site. In both the DSV and the DMV, CEC (100 microM) caused a significant shift in the EC50 values for phenylephrine and methoxamine. Maximum responses in the DMV were significantly attenuated while those in the DSV were unaffected when total tension was considered. 4. Studies of the functional interactions of the DSV and the DMV with WB 4101 or 5-methylurapidil (5-MU) suggested the presence of alpha 1D-adrenoceptors in the DSV and alpha 1A-adrenoceptors in the DMV. The receptors inactivated by CEC in the DMV and DSV may represent some or all of the receptors with properties of alpha 1D and alpha 1A-receptors present in the two veins. Studies of radioligand binding interactions of these two antagonists with [3H]-prazosin, were consistent with the presence of some alpha 1D-receptors in DSV and alpha 1A-receptors in DMV. These findings raise questions about the selectivity of CEC in differentiating alpha 1-adrenoceptor subtypes. 5. B-HT 920 caused contractions in the DSV smaller than those to the alpha 1-agonists but the maximum was not affected by CEC pretreatment. The EC50 values were shifted to the left after CEC. In radioligand binding studies, B-HT 920 competition for [3H]-rauwolscine binding was not significantly affected by CEC pretreatment. 6. These results suggest the presence of unusual alpha-adrenoceptors in the DSV. In addition to alpha 2-adrenoceptors, receptors recognizing rauwolscine as well as prazosin, WB 4101, phenylephrine and methoxamine and susceptible to inactivation by CEC are present. They appear to be, in part, unusual alpha 1D-adrenoceptors.
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Affiliation(s)
- E E Daniel
- Department of Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
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42
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Scalia R, Gauthier TW, Murohara T, Lefer AM. Oligotide attenuates leukocyte-endothelial cell interaction via P-selectin in the rat mesenteric vascular bed. Eur J Pharmacol 1996; 296:181-7. [PMID: 8838455 DOI: 10.1016/0014-2999(95)00695-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
A novel single stranded polydeoxyribonucleotide (oligotide) was studied for its ability to modulate leukocyte-endothelial cell interaction, by means of intravital microscopy in the rat mesenteric microvasculature. Superfusion of the rat mesentery with 50 microM NG-nitro-L-arginine methyl ester (L-NAME), caused a significant, time-dependent increase in leukocyte rolling and adherence compared to control rats superfused with Krebs-Henseleit solution. However, oligotide (15 mg/kg i.v.) consistently reduced the L-NAME-induced leukocyte rolling (62 +/- 14 vs. 23 +/- 3 cells/min; P < 0.02) and adherence (11 +/- 2 vs. 4 +/- 1 cells/100 microns length of venule P < 0.01), without altering systemic blood pressure or mesenteric venular shear rate. Moreover, immunohistochemical localization of P-selectin expression on mesenteric venules was significantly increased (P < 0.01) after exposure to L-NAME, which was significantly attenuated by oligotide (P < 0.05). Similar results were also obtained by flow cytometric analysis performed on rat platelets. Stimulation of rat platelets with L-NAME significantly (P < 0.05) increased the fluorescence intensity of P-selectin, while the concomitant treatment of isolated rat platelets with L-NAME plus oligotide significantly (P < 0.005) attenuated P-selectin fluorescence intensity. Our data demonstrate that in vivo administration of oligotide can reduce leukocyte rolling and adherence in the mesenteric rat microvasculature by attenuating P-selectin expression, and confirming the key role of nitric oxide as an important regulator of leukocyte-endothelial cell interaction.
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Affiliation(s)
- R Scalia
- Department of Physiology, Thomas Jefferson University, Philadelphia, PA 19107-6799, USA
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43
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Schleiffer R, Galluser M, Raul F. Intestinal absorption of calcium in vivo is dependent on endogenous nitric oxide. J Pharmacol Exp Ther 1995; 275:1427-32. [PMID: 8531112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
This study examines the role of nitric oxide (NO) in the regulation of calcium absorption in the small intestine. Calcium absorption was quantified by measuring 45Ca++ transport from lumen to blood in an intestinal segment (duodenum and 20 cm of the proximal jejunum) perfused by both intraluminal and vascular routes in anesthetized rats. When administered i.v. as bolus injections, NG-nitro-L-arginine methyl ester (L-NAME, 10 mg.kg-1), an inhibitor of NO biosynthesis, decreased calcium absorption with a concomitant increase in blood pressure and a decrease in mesenteric blood flow. Conversely, the nitrovasodilators 3-morpholinosydnonimine (2 mg.kg-1) and S-nitroso-N-acetylpenicillamine (10 micrograms.kg-1), which generate NO spontaneously, both increased calcium absorption with no change in mesenteric blood flow. When infused i.v., L-NAME (3 mg.hr-1.kg-1 for 40 min) induced a decrease in calcium absorption that was reversed by the NO donor sodium nitroprusside (1.5 mg.hr-1.kg-1 when infused for the last 20 min of the 40-min L-NAME infusion). Sodium nitroprusside infusion (1.5 mg.hr-1.kg-1) caused an increase in calcium absorption that was not reversed by L-NAME (3 and 30 mg.hr-1.kg-1). The present findings suggest that NO is involved in basal calcium absorption in rat small intestine in vivo.
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Affiliation(s)
- R Schleiffer
- Institut de Recherche contre les Cancers de l'Appareil Digestif, IRCAD, Hôpitaux Universitaires, Strasbourg, France
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Zimmermann B, Somlyo AV, Ellis-Davies GC, Kaplan JH, Somlyo AP. Kinetics of prephosphorylation reactions and myosin light chain phosphorylation in smooth muscle. Flash photolysis studies with caged calcium and caged ATP. J Biol Chem 1995; 270:23966-74. [PMID: 7592592 DOI: 10.1074/jbc.270.41.23966] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The pre-myosin light chain (MLC20) phosphorylation components of the lag phase (td) of contractile activation were determined in permeabilized smooth muscles activated by photolytic release of ATP from caged ATP and/or Ca2+ from 4-(2-nitrophenyl)-EGTA (NP-EGTA). Calmodulin (CaM) shortened the td (470 ms at 0 added CaM) that followed Ca2+ release, but its effect (td = approximately 200 ms) saturated at 40 microM. Photolysis of caged ATP following preequilibration with identical [Ca4CaM] shortened td to 41 ms. The rate of phosphorylation was very fast (3.5 s-1 at 22 degrees C in the presence of 5 microM exogenous CaM) following photolysis of caged ATP, and, following Ca2+ release, phosphorylation was accelerated by CaM. Simultaneous photolysis of caged ATP and NP-EGTA was followed by a td of 194 ms at 5 microM CaM and a rate of MLC20 phosphorylation intermediate between these parameters following photolysis of, respectively, NP-EGTA and caged ATP. In the presence of the normal, total endogenous CaM content (37 +/- 4 microM) of protal vein smooth muscles td was 565 ms. Steady state maximum force at pCa 5.5 was increased by much lower (100 nM) exogenous [CaM] than was required (> 2.5 microM) to shorten the td. We estimate the endogenous CaM available under steady state conditions in vivo to be approximately 0.25 microM and probably less during a rapid Ca2+ transient. We conclude that the [CaM] dependence of the kinetics of MLC20 phosphorylation and force development (t1/2 and td) initiated by Ca2+ reflects the recruitment of a slowly diffusible component of total CaM. The relatively long duration of td (197 ms) at saturating [CaM] suggests the contribution to td of an additional component, possibly a prephosphorylation activation/isomerization of the Ca4CaM myosin light chain kinase complex (Török, K., and Trentham, D. R. (1994) Biochemistry 33, 12807-12820). The relatively short delay (108 ms in the presence of 40 microM CaM) following simultaneous photolysis of NP-EGTA and caged ATP suggests that preincubation with ATP (prior to photolysis of NP-EGTA) may inhibit the formation of a preactive Ca2CaM myosin light chain kinase complex.
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Affiliation(s)
- B Zimmermann
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville 22908, USA
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45
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Berthiaume N, Claing A, Regoli D, Warner TD, D'Orléans-Juste P. Characterization of receptors for kinins and neurokinins in the arterial and venous mesenteric vasculatures of the guinea-pig. Br J Pharmacol 1995; 115:1319-25. [PMID: 7582563 PMCID: PMC1908793 DOI: 10.1111/j.1476-5381.1995.tb15043.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
1. In the present work, we have studied the microvascular reactivity of the arterial and venous mesenteric beds of the guinea-pig to bradykinin, neurokinins and other agents. 2. The vasoactive properties of three selective agonists for neurokinin receptors, namely [Sar9, Met (O2)11]SP (NK1), [beta-Ala8]NKA(4-10) (NK2) and [MePhe7]NKB (NK3), were evaluated on precontracted arterial and venous mesenteric vasculatures of the guinea-pig. The NK1-selective agonist, [Sar9,Met(O2)11]SP (1 to 1000 pmol), induced an endothelium-dependent and N omega-nitro-L-arginine methyl ester (L-NAME)-sensitive relaxation of the arterial vasculature precontracted with methoxamine, whereas the NK2 and NK3-selective agonists were virtually inactive at high doses (1000 pmol). 3. The three selective neurokinin receptor agonists were inactive in the non-precontracted arterial and venous mesenteric vasculatures as well as in the precontracted venous mesenteric vasculature. 4. Bradykinin (0.1 to 100 pmol) induced a marked dose- and endothelium-dependent vasodilatation of the precontracted arterial and venous vasculatures. ED50 values were 5.5 pmol on the arterial side and 1.9 pmol on the venous side. In contrast, desArg9-bradykinin was inactive at doses up to 1000 pmol. Furthermore, on the arterial and venous sides, a higher dose of bradykinin (1000 pmol), induced a biphasic effect, a transient constriction followed by a marked and sustained vasodilatation. The vasodilator effects of bradykinin were abolished by Hoe 140 (0.1 microM) and CHAPS, markedly reduced by L-NAME and were unaffected by [Leu8]desArg9-bradykinin (0.1 microM) on both sides of the mesenteric vasculature. Hoe 140 also abolished the arterial vasoconstrictions induced by high doses of bradykinin. 5. Noradrenaline, angiotensin II and endothelin-1 produced contractions on both sides of the mesenteric circulation, while acetylcholine (arterial side) and sodium nitroprusside (arterial and venous sides) caused vasodilatation.6. Our study supports the view that NK1 receptors responsible for vasodilatation are present solely in the endothelium of the arterial mesenteric vasculature of the guinea-pig. On the other hand, bradykinin(0.1 to 100 pmol) exerts predominantly vasodilator effects on both sides of the mesenteric vasculature via selective activation of B2 receptors located on the endothelium. The same receptor type located on the smooth muscle appears to be responsible for the arterial and venous constriction with high doses of bradykinin.
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Affiliation(s)
- N Berthiaume
- Department of Pharmacology, Medical School, Université de Sherbrooke, Québec, Canada
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Seiffge D, Bissinger T, Kremer E, Laux V, Schleyerbach R. Inhibitory effects of pentoxifylline on LPS-induced leukocyte adhesion and macromolecular extravasation in the microcirculation. Inflamm Res 1995; 44:281-6. [PMID: 8564524 DOI: 10.1007/bf02032569] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Pentoxifylline (PTX) has been shown to combat effectively endotoxin induced symptoms of shock or inflammation by reducing both leukocyte activation and endogenous cytokine formation. With regard to blood perfusion, inflammation is defined as a local reaction to injury of the living microvasculature and its content. Leukocyte margination, rolling, adhesion, and emigration is mediated by adhesion molecules along the endothelium of postcapillary venules and is considered to be an important step in the inflammatory response. Changes in the vascular integrity can be estimated in terms of increased extravasation of macromolecules. Using intravital microscopy with the help of an analogous video image processing system we measured the effect of PTX on lipopolysaccharide (LPS, 15 mg/kg i.v.) induced leukocyte adhesion and extravasation of FITC-rat serum albumin (FITC-RSA) in rat mesenteric venules. The changes in vascular permeability correlates significantly (r = 0.75) with a locally increased number of adherent leukocytes. PTX significantly inhibits both leukocyte adhesion and extravasation of FITC-RSA dose dependently. Our results indicate that PTX effectively preserves vascular integrity in the microcirculation by acting primarily on LPS-induced leukocyte adhesion.
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Affiliation(s)
- D Seiffge
- Hoechst AG Werk Kalle-Albert, Wiesbaden, Germany
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47
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Abstract
Organs of the digestive tract, including pancreas, small intestine, and colon, have mechanisms to modulate plasma thiol-disulfide balance. Because plasma glutathione disulfide (GSSG) concentration may be elevated from < 1 microM in control rats to over 25 microM during oxidative stress, we examined whether GSSG was cleared from rat mesenteric vasculature. When 100 microM GSSG was perfused through the gut via the superior mesenteric artery, an average of 45% was lost in a single pass. Results showed that gamma-glutamyltransferase (gamma-GT)-dependent and -independent mechanisms were involved in GSSG loss. Acivicin (AT125) treatment inhibited gamma-GT activity in the mesenteric vasculature by 94% and attenuated the loss of GSSG equivalents by 44%. These results supported a role for gamma-GT in GSSG loss from the mesenteric vasculature but indicated that still other mechanisms were involved in GSSG clearance. Elevations of portal levels of glutathione (GSH) and the mixed disulfide of cysteine and GSH (CySSG) also occurred with vascular GSSG perfusion and could account for about 40% of GSSG equivalents lost. Because portal elevations of GSH and CySSG were not inhibited by AT125, they were formed by a gamma-GT-independent mechanism(s). Given that cysteine was present in the mesenteric vasculature, the most likely mechanism to explain GSH and CySSG formation was via nonenzymatic thiol-disulfide exchange between GSSG and cysteine. Uptake of vascular GSSG by pancreas, small intestine (jejunum and ileum), or colon apparently did not occur as tissue contents of GSSG or GSH were not elevated, except for a small elevation of GSH in pancreas when mesenteric gamma-GT was inhibited with AT125. Additionally, GSSG was not transported from mesenteric vasculature into the small intestinal lumen because luminal levels of GSSG or GSH were not elevated. Further, total cysteine equivalents in lumen were unchanged indicating that GSSG was not transported to lumen and degraded to cystine by gamma-GT and dipeptidases localized to the intestinal brush-border. These results indicate that GSSG present in mesenteric vasculature is metabolized in the vascular compartment by gamma-GT-dependent and -independent reactions; together, these account for over 80% of lost GSSG equivalents. They also suggest that organs of the mesentery may play a quantitatively important role in plasma GSSG clearance and modulation of vascular thiol-disulfide balance.
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Affiliation(s)
- L J Dahm
- Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia 30322
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48
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Abstract
Caffeine significantly (p < 0.05) increased the output of prostacyclin (PGI2) from the perfused rat mesenteric vascular bed. The outputs of PGE2 and PGF2 alpha were also increased by caffeine. This stimulatory response to caffeine did not show rapid desensitization. Ryanodine also increased PG output, suggesting that caffeine may be acting via the stimulation of a ryanodine receptor. The increased production of a vasodilator such as PGI2 from blood vessels following exposure to caffeine may explain why caffeine has a beneficial effect in angina.
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Affiliation(s)
- E K Naderali
- Department of Pharmacology, University of Edinburgh Medical School, UK
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49
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Abstract
The ability of putative selective irreversible ligands SZL-49 (1-(4-amino-6,7-dimethoxy-2,5-diene-2-carbonyl)) and CEC (chlorethylclonidine), for alpha 1A and alpha 1B adrenoceptor subtypes, respectively, to affect alpha 1-adrenoceptors of canine aorta microsomal membranes was investigated. These membranes contain an apparently homogeneous population of [3H]prazosin binding sites. SZL-49, like phenoxybenzamine, abolished all binding of [3H]prazosin. CEC abolished 75% of the prazosin binding sites under the most stringent conditions we applied. However, the remaining 25% of binding sites was identical in affinity for prazosin with control membranes, and competition studies of other subtype-selective ligands revealed unchanged ability to complete against CEC-sensitive and -insensitive sites. We concluded that SZL-49 and CEC are not alpha 1A- and alpha 1B-adrenoceptor selective under in vitro conditions. Our data led to the hypothesis that canine aortic membranes contain exclusively alpha 1B-adrenoceptors but that current tools for identifying alpha 1-adrenoceptor subtypes proved inadequate in vitro in this study.
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Affiliation(s)
- K H Hoo
- Department of Biomedical Sciences, McMaster University, Hamilton, ON, Canada
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50
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Kim DC, Burton PS, Borchardt RT. A correlation between the permeability characteristics of a series of peptides using an in vitro cell culture model (Caco-2) and those using an in situ perfused rat ileum model of the intestinal mucosa. Pharm Res 1993; 10:1710-4. [PMID: 8302755 DOI: 10.1023/a:1018961828510] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
In an attempt to establish an in vitro/in situ correlation of intestinal permeability data, the permeability coefficients (Papp) for a series of model peptides, which were determined using an in situ perfused rat ileum model, were compared to the permeability coefficients (Pmono) determined using an in vitro cell culture model (Caco-2). The model peptides, which were all blocked on the N-terminal (acetyl, Ac) and the C-terminal (amide, NH2) ends, consisted of D-phenylalanine (F) residues (e.g., AcFNH2, AcFFNH2, AcFFFNH2). To alter the degree of hydrogen bonding potential, the nitrogens of the amide bonds were sequentially methylated [e.g., AcFF(Me)FNH2, AcF(Me)F(Me)FNH2, Ac(Me)F(Me)FNH2, Ac(Me)F(Me)F(Me)]. These peptides were shown not to be metabolized in the in situ perfused rat ileum system. The results of the transport experiments showed that there were poor correlations between the apparent permeability coefficients (Papp) determined in an in situ perfused rat ileum model and the octanol-water partition coefficients (r = 0.60) or the hydrogen bonding numbers (r = 0.63) of these peptides. However, good correlations were observed between the in situ Papp values for these peptides and their partition coefficients in heptane-ethylene glycol (r = 0.96) and the differences in their partition coefficients between octanol-water and isooctane-water (r = 0.86). These results suggest that lipophilicity may not be the major factor in determining the intestinal permeability of these peptides and that hydrogen bonding potential may be a major contributing factor. These results suggest that lipophilicity may not be the major factor in determining the intestinal permeability of these peptides and that hydrogen bonding potential may be a major contributing factor.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- D C Kim
- Department of Pharmaceutical Chemistry, University of Kansas, Lawrence 66045
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