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Gouaref I, Otmane A, Makrelouf M, Abderrhmane SA, Haddam AEM, Koceir EA. Crucial Interactions between Altered Plasma Trace Elements and Fatty Acids Unbalance Ratio to Management of Systemic Arterial Hypertension in Diabetic Patients: Focus on Endothelial Dysfunction. Int J Mol Sci 2024; 25:9288. [PMID: 39273236 PMCID: PMC11395650 DOI: 10.3390/ijms25179288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2024] [Revised: 08/20/2024] [Accepted: 08/22/2024] [Indexed: 09/15/2024] Open
Abstract
The coexistence of SAH with T2DM is a common comorbidity. In this study, we investigated the link between altered plasma antioxidant trace elements (ATE: manganese, selenium, zinc, and copper) and fatty acids ratio (FAR: polyunsaturated/saturated) imbalance as transition biomarkers between vascular pathology (SAH) to metabolic pathology (T2DM). Our data revealed strong correlation between plasma ATE and FAR profile, which is modified during SAH-T2DM association compared to the healthy group. This relationship is mediated by lipotoxicity (simultaneously prominent visceral adipose tissue lipolysis, significant flow of non-esterified free fatty acids release, TG-Chol-dyslipidemia, high association of total SFA, palmitic acid, arachidonic acid, and PUFA ω6/PUFA ω3; drop in tandem of PUFA/SFA and EPA + DHA); oxidative stress (lipid peroxidation confirmed by TAS depletion and MDA rise, concurrent drop of Zn/Cu-SOD, GPx, GSH, Se, Zn, Se/Mn, Zn/Cu; concomitant enhancement of Cu, Mn, and Fe); endothelial dysfunction (endotheline-1 increase); athero-thrombogenesis risk (concomitant rise of ApoB100/ApoA1, Ox-LDL, tHcy, and Lp(a)), and inflammation (higher of Hs-CRP, fibrinogen and ferritin). Our study opens to new therapeutic targets and to better dietary management, such as to establishing dietary ATE and PUFA ω6/PUFA ω3 or PUFA/SFA reference values for atherosclerotic risk prevention in hypertensive/diabetic patients.
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Affiliation(s)
- Ines Gouaref
- Bioenergetics and Intermediary Metabolism Team, Laboratory of Biology and Organism Physiology, Biological Sciences Faculty, Nutrition and Pathologies Post Graduate School, Houari Boumediene University of Sciences and Technology (USTHB), Bab Ezzouar, Algiers 16123, Algeria
- Tamayouz Laboratory, Centre de Recherche en Biotechnologie (CRBT), Ali Mendjli Nouvelle Ville UV 03 BP E73, Constantine 25000, Algeria
| | - Amel Otmane
- Biochemistry and Genetics Laboratory, University Hospital Center, Mohamed Lamine Debaghine, Bab El Oued, Algiers 16000, Algeria
| | - Mohamed Makrelouf
- Biochemistry and Genetics Laboratory, University Hospital Center, Mohamed Lamine Debaghine, Bab El Oued, Algiers 16000, Algeria
| | - Samir Ait Abderrhmane
- Diabetology Unit, University Hospital Center, Mohamed Seghir Nekkache (ex. HCA de Aïn Naâdja), Algiers 16208, Algeria
| | - Ali El Mahdi Haddam
- Diabetology Unit, University Hospital Center, Mohamed Lamine Debaghine, Algiers I-University, Bab El Oued, Algiers 16000, Algeria
| | - Elhadj-Ahmed Koceir
- Bioenergetics and Intermediary Metabolism Team, Laboratory of Biology and Organism Physiology, Biological Sciences Faculty, Nutrition and Pathologies Post Graduate School, Houari Boumediene University of Sciences and Technology (USTHB), Bab Ezzouar, Algiers 16123, Algeria
- Tamayouz Laboratory, Centre de Recherche en Biotechnologie (CRBT), Ali Mendjli Nouvelle Ville UV 03 BP E73, Constantine 25000, Algeria
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Patel S, Fedinec AL, Liu J, Weiss MA, Pourcyrous M, Harsono M, Parfenova H, Leffler CW. H 2S mediates the vasodilator effect of endothelin-1 in the cerebral circulation. Am J Physiol Heart Circ Physiol 2018; 315:H1759-H1764. [PMID: 30265150 DOI: 10.1152/ajpheart.00451.2018] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
H2S is an endogenous gasotransmitter that increases cerebral blood flow. In the cerebral vascular endothelium, H2S is produced by cystathionine δ-lyase (CSE). Endothelin-1 (ET-1) has constrictor and dilator influences on the cerebral circulation. The mechanism of the vasodilation caused by ET-1 may involve endothelium-derived factors. We hypothesize that ET-1-elicited dilation of pial arterioles requires an elevation of H2S production in the cerebral vascular endothelium. We investigated the effects of ET-1 on CSE-catalyzed brain H2S production and pial arteriolar diameter using cranial windows in newborn pigs in vivo. H2S was measured in periarachnoid cerebrospinal fluid. ET-1 (10-12-10-8 M) caused an elevation of H2S that was reduced by the CSE inhibitors propargylglycine (PPG) and β-cyano-l-alanine (BCA). Low doses of ET-1 (10-12-10-11 M) produced vasodilation of pial arterioles that was blocked PPG and BCA, suggesting the importance of H2S influences. The vasodilator effects of H2S may require activation of smooth muscle cell membrane ATP-sensitive K+ (KATP) channels and large-conductance Ca2+-activated K+ (BK) channels. The KATP inhibitor glibenclamide and the BK inhibitor paxilline blocked CSE/H2S-dependent dilation of pial arterioles to ET-1. In contrast, the vasoconstrictor response of pial arterioles to 10-8 M ET-1 was not modulated by PPG, BCA, glibenclamide, or paxilline and, therefore, was independent of CSE/H2S influences. Pial arteriolar constriction response to higher levels of ET-1 was independent of CSE/H2S and KATP/BKCa channel activation. These data suggest that H2S is an endothelium-derived factor that mediates the vasodilator effects of ET-1 in the cerebral circulation via a mechanism that involves activation of KATP and BK channels in vascular smooth muscle. NEW & NOTEWORTHY Disorders of the cerebral circulation in newborn infants may lead to lifelong neurological disabilities. We report that vasoactive peptide endothelin-1 exhibits vasodilator properties in the neonatal cerebral circulation by stimulating production of H2S, an endothelium-derived messenger with vasodilator properties. The ability of endothelin-1 to stimulate brain production of H2S may counteract the reduction in cerebral blood flow and prevent the cerebral vascular dysfunction caused by stroke, asphyxia, cerebral hypoxia, ischemia, and vasospasm.
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Affiliation(s)
- Shalinkumar Patel
- Division of Neonatology, Department of Pediatrics, University of Tennessee Health Science Center , Memphis, Tennessee
| | - Alexander L Fedinec
- Laboratory for Research in Neonatal Physiology, Departments of Physiology and Pediatrics, University of Tennessee Health Science Center , Memphis, Tennessee
| | - Jiangxiong Liu
- Laboratory for Research in Neonatal Physiology, Departments of Physiology and Pediatrics, University of Tennessee Health Science Center , Memphis, Tennessee
| | - Max A Weiss
- Laboratory for Research in Neonatal Physiology, Departments of Physiology and Pediatrics, University of Tennessee Health Science Center , Memphis, Tennessee
| | - Massroor Pourcyrous
- Division of Neonatology, Department of Pediatrics, University of Tennessee Health Science Center , Memphis, Tennessee.,Laboratory for Research in Neonatal Physiology, Departments of Physiology and Pediatrics, University of Tennessee Health Science Center , Memphis, Tennessee
| | - Mimily Harsono
- Division of Neonatology, Department of Pediatrics, University of Tennessee Health Science Center , Memphis, Tennessee
| | - Helena Parfenova
- Laboratory for Research in Neonatal Physiology, Departments of Physiology and Pediatrics, University of Tennessee Health Science Center , Memphis, Tennessee
| | - Charles W Leffler
- Division of Neonatology, Department of Pediatrics, University of Tennessee Health Science Center , Memphis, Tennessee.,Laboratory for Research in Neonatal Physiology, Departments of Physiology and Pediatrics, University of Tennessee Health Science Center , Memphis, Tennessee
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Calpain 1 cleaves and inactivates prostacyclin synthase in mesenteric arteries from diabetic mice. Basic Res Cardiol 2016; 112:10. [DOI: 10.1007/s00395-016-0596-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Accepted: 12/12/2016] [Indexed: 12/18/2022]
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Nuclear factor-κB is involved in oxyhemoglobin-induced endothelin-1 expression in cerebrovascular muscle cells of the rabbit basilar artery. Neuroreport 2016; 27:875-82. [PMID: 27391329 DOI: 10.1097/wnr.0000000000000615] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The present research was designed to investigate whether endothelin-1 (ET-1) secretion can be induced by oxyhemoglobin and whether nuclear factor κB (NF-κB) is involved in the regulation of ET-1 transcription in cerebrovascular muscle cells. Cerebrovascular muscle cells isolated from a rabbit basilar artery were stimulated by oxyhemoglobin (OxyHb) and ET-1 production was increased significantly in the supernatant. Inhibition of NF-κB with pyrrolidine dithiocarbamate and small interfering RNA decreased the expression of ET-1. Nuclear translocation of NF-κB and the degradation of IkB-α was observed with the stimulation of OxyHb. The supernatant obtained from cerebrovascular muscle cells stimulated by OxyHb produced contractions in arterial rings and was blocked by the ET-1 receptor antagonist (BQ-123). The time course of the OxyHb-induced contractions of the basilar artery rings correlated with the time course of the OxyHb-induced ET-1 secretion. The contraction of the basilar artery rings induced by OxyHb was attenuated when the artery rings were preincubated with pyrrolidine dithiocarbamate and SN50 (20 and 10 µM, respectively). These results indicate that cerebrovascular muscle cells may be an important source of ET-1 production after subarachnoid hemorrhage. NF-κB was involved in the expression of ET-1 and the inhibition of the NF-κB pathway may be beneficial for the treatment of cerebral vasospasm.
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Yu QJ, Tao H, Wang X, Li MC. Targeting brain microvascular endothelial cells: a therapeutic approach to neuroprotection against stroke. Neural Regen Res 2016; 10:1882-91. [PMID: 26807131 PMCID: PMC4705808 DOI: 10.4103/1673-5374.170324] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Brain microvascular endothelial cells form the interface between nervous tissue and circulating blood, and regulate central nervous system homeostasis. Brain microvascular endothelial cells differ from peripheral endothelial cells with regards expression of specific ion transporters and receptors, and contain fewer fenestrations and pinocytotic vesicles. Brain microvascular endothelial cells also synthesize several factors that influence blood vessel function. This review describes the morphological characteristics and functions of brain microvascular endothelial cells, and summarizes current knowledge regarding changes in brain microvascular endothelial cells during stroke progression and therapies. Future studies should focus on identifying mechanisms underlying such changes and developing possible neuroprotective therapeutic interventions.
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Affiliation(s)
- Qi-Jin Yu
- Department of Anesthesiology, Renmin Hospital of Wuhan University, Wuhan, Hubei Province, China
| | - Hong Tao
- Department of Anesthesiology, Renmin Hospital of Wuhan University, Wuhan, Hubei Province, China
| | - Xin Wang
- Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Ming-Chang Li
- Department of Neurosurgery, Renmin Hospital of Wuhan University, Wuhan, Hubei Province, China
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Participation of nitric oxide pathway in the relaxation response induced by E-cinnamaldehyde oxime in superior mesenteric artery isolated from rats. J Cardiovasc Pharmacol 2013; 62:58-66. [PMID: 23842292 DOI: 10.1097/fjc.0b013e31829013ff] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
For many years, nitric oxide (NO) has been studied as an important mediator in the control of vascular tone. Endothelial deficiencies that diminish NO production can result in the development of several future cardiovascular diseases, such as hypertension and arteriosclerosis. In this context, new drugs with potential ability to donate NO have been studied. In this study, 3 aromatic oximes [benzophenone oxime, 4-Cl-benzophenone oxime, and E-cinnamaldehyde oxime (E-CAOx)] induced vasorelaxation in endothelium-denuded and intact superior mesenteric rings precontracted with phenylephrine. E-CAOx demonstrated the most potent effect, and its mechanism of action was evaluated. Vascular reactivity experiments demonstrated that the effect of E-CAOx was reduced by the presence of 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, 1H[1,2,4,]oxadiazolo[4,3-a]quinoxalin-1-one, and (Rp)-8-(para-chlorophenylthio)guanosine-3',5'-cyclic monophosphorothioate, suggesting the participation of NO/sGC/PKG pathway. NO donation seems to be mediated through nicatinamide adenine dinucleotide phosphate-dependent reductases because 7-ethoxyresorufin decreased the effect of E-CAOx on vascular reactivity and reduced NO formation as detected by flow cytometry using the NO indicator diaminofluorescein 4,5-diacetate. Further downstream of NO donation, K+ subtype channels were also shown to be involved in the E-CAOx vasorelaxant effect. The present study showed that E-CAOx acts like an NO donor, activating NO/sGC/PKG pathway and thus K+ channels.
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Pulina MV, Zulian A, Baryshnikov SG, Linde CI, Karashima E, Hamlyn JM, Ferrari P, Blaustein MP, Golovina VA. Cross talk between plasma membrane Na(+)/Ca (2+) exchanger-1 and TRPC/Orai-containing channels: key players in arterial hypertension. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 961:365-74. [PMID: 23224895 DOI: 10.1007/978-1-4614-4756-6_31] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Arterial smooth muscle (ASM) Na(+)/Ca(2+) exchanger type 1 (NCX1) and TRPC/Orai-containing receptor/store-operated cation channels (ROC/SOC) are clustered with α2 Na(+) pumps in plasma membrane microdomains adjacent to the underlying junctional sarcoplasmic reticulum. This arrangement enables these transport proteins to function as integrated units to help regulate local Na(+) metabolism, Ca(2+) signaling, and arterial tone. They thus influence vascular resistance and blood pressure (BP). For instance, upregulation of NCX1 and TRPC6 has been implicated in the pathogenesis of high BP in several models of essential hypertension. The models include ouabain-induced hypertensive rats, Milan hypertensive rats, and Dahl salt-sensitive hypertensive rats, all of which exhibit elevated plasma ouabain levels. We suggest that these molecular mechanisms are key contributors to the increased vascular resistance ("whole body autoregulation") that elevates BP in essential hypertension. Enhanced expression and function of ASM NCX1 and TRPC/Orai1-containing channels in hypertension implies that these proteins are potential targets for pharmacological intervention.
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Affiliation(s)
- Maria V Pulina
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
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Dore-Duffy P, Wang S, Mehedi A, Katyshev V, Cleary K, Tapper A, Reynolds C, Ding Y, Zhan P, Rafols J, Kreipke CW. Pericyte-mediated vasoconstriction underlies TBI-induced hypoperfusion. Neurol Res 2012; 33:176-86. [PMID: 21801592 DOI: 10.1179/016164111x12881719352372] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
OBJECTIVES Endothelin-1 is a 21-amino acid peptide that together with specific receptors, A (ETrA) and B (ETrB) is induced following traumatic brain injury (TBI) and has been closely linked to regulation of cerebral vasospasm, oxidative stress, and hypoperfusion. Specific endothelin receptor antagonists have been shown to ameliorate early evidence of neuronal cell injury, activation of microglial cells, and hypoperfusion following TBI. The exact mechanism involved in TBI-induced hypoperfusion is still unclear; however, it is thought that endothelin-1 engagement of ETrA is primarily responsible for changes in blood flow. In this study we question the role of the microvascular pericyte in endothelin-1-mediated pathophysiology in TBI. METHODS Pericyte expression of endothelin-1, ETrA, and ETrB was examined in primary culture and in sham and impacted rat brain. Adult male rats were also given intracerebroventricular injections of ETrA (BQ-123) before being subjected to TBI using a closed head acceleration impact model. RESULTS Primary pericytes express both endothelin-1 and its receptors ETrA and ETrB. Following TBI, the number of alpha-smooth muscle actin (SMA) positive pericytes located in microvessels is significantly increased by 4 hours post-traumatic impact. Increases in pericyte expression of alpha-SMA correlated with evidence of a reduction in both arteriolar and capillary diameter. Capillary endothelin-1, ETrA, and ETrB transcript and protein was also increased. Increased endothelin-1 expression was seen by 2-4 hours post-impact. Upregulation of receptors was observed by 4-8 hours and maximum by 24 hours. ETrA antagonists decreased the number of alpha-SMA(+) pericytes as well as changes in microvascular diameter. CONCLUSION These results suggest that decreased vasoconstriction following TBI may be due to an endothelin-1-induced pericyte-mediated regulation of microvessel blood flow following TBI. Furthermore, results suggest that ETrA antagonists ameliorate trauma induced hypoperfusion, in part, by inhibiting endothelin-1-mediated upregulation of alpha-SMA in pericytes.
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Affiliation(s)
- Paula Dore-Duffy
- Department of Neurology, Wayne State University School of Medicine, Detroit, MI 48201, USA.
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Rafols JA, Kreipke CW. Current brain endothelin research: a pathway to novel approaches impacting clinical trials. Neurol Res 2011; 33:115-8. [DOI: 10.1179/016164111x12881719352057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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Tigyi G. Aiming drug discovery at lysophosphatidic acid targets. Br J Pharmacol 2010; 161:241-70. [PMID: 20735414 PMCID: PMC2989581 DOI: 10.1111/j.1476-5381.2010.00815.x] [Citation(s) in RCA: 140] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2009] [Revised: 02/12/2010] [Accepted: 03/20/2010] [Indexed: 12/22/2022] Open
Abstract
Lysophosphatidic acid (LPA, 1-radyl-2-hydroxy-sn-glycero-3-phosphate) is the prototype member of a family of lipid mediators and second messengers. LPA and its naturally occurring analogues interact with G protein-coupled receptors on the cell surface and a nuclear hormone receptor within the cell. In addition, there are several enzymes that utilize LPA as a substrate or generate it as a product and are under its regulatory control. LPA is present in biological fluids, and attempts have been made to link changes in its concentration and molecular composition to specific disease conditions. Through their many targets, members of the LPA family regulate cell survival, apoptosis, motility, shape, differentiation, gene transcription, malignant transformation and more. The present review depicts arbitrary aspects of the physiological and pathophysiological actions of LPA and attempts to link them with select targets. Many of us are now convinced that therapies targeting LPA biosynthesis and signalling are feasible for the treatment of devastating human diseases such as cancer, fibrosis and degenerative conditions. However, successful targeting of the pathways associated with this pleiotropic lipid will depend on the future development of as yet undeveloped pharmacons.
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Affiliation(s)
- Gabor Tigyi
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN, USA.
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Mostefai HA, Meziani F, Mastronardi ML, Agouni A, Heymes C, Sargentini C, Asfar P, Martinez MC, Andriantsitohaina R. Circulating Microparticles from Patients with Septic Shock Exert Protective Role in Vascular Function. Am J Respir Crit Care Med 2008; 178:1148-55. [DOI: 10.1164/rccm.200712-1835oc] [Citation(s) in RCA: 131] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
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Hemolysate-induced expression of intercellular adhesion molecule-1 and monocyte chemoattractant protein-1 expression in cultured brain microvascular endothelial cells via through ROS-dependent NF-kappaB pathways. Cell Mol Neurobiol 2008; 29:87-95. [PMID: 18726687 DOI: 10.1007/s10571-008-9300-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2008] [Accepted: 07/31/2008] [Indexed: 01/04/2023]
Abstract
In order to determine the possible effects of hemolysate on brain microvascular endothelial cells (BMECs), we examined the effects of hemolysate on the expression of intercellular adhesion molecule-1 (ICAM-1) and monocyte chemoattractant protein-1 (MCP-1), generation of reactive oxygen species (ROS), and NF-kappaB activation in rat BMECs. Hemolysate induced the expression of ICAM-1 and MCP-1 in endothelial cells. In addition, hemolysate stimulated nuclear translocation of the p65 subunit of NF-kappaB, and NF-kappaB DNA-binding activity in BMECs. Furthermore, hemolysate increased ROS generation, and hemolysate-induced ICAM-1and MCP-1 expression and NF-kappaB activation were abrogated in the presence of the direct scavenger of ROS. Taken together, our results indicate that hemolysate can induce inflammatory responses that increase expression of ICAM-1 and MCP-1, through ROS-dependent NF-kappaB activation in BMECs.
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Signal transduction underlying the control of urinary bladder smooth muscle tone by muscarinic receptors and beta-adrenoceptors. Naunyn Schmiedebergs Arch Pharmacol 2007; 377:449-62. [PMID: 18060543 PMCID: PMC2480512 DOI: 10.1007/s00210-007-0208-0] [Citation(s) in RCA: 117] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2007] [Accepted: 10/21/2007] [Indexed: 12/17/2022]
Abstract
The normal physiological contraction of the urinary bladder, which is required for voiding, is predominantly mediated by muscarinic receptors, primarily the M3 subtype, with the M2 subtype providing a secondary backup role. Bladder relaxation, which is required for urine storage, is mediated by β-adrenoceptors, in most species involving a strong β3-component. An excessive stimulation of contraction or a reduced relaxation of the detrusor smooth muscle during the storage phase of the micturition cycle may contribute to bladder dysfunction known as the overactive bladder. Therefore, interference with the signal transduction of these receptors may be a viable approach to develop drugs for the treatment of overactive bladder. The prototypical signaling pathway of M3 receptors is activation of phospholipase C (PLC), and this pathway is also activated in the bladder. Nevertheless, PLC apparently contributes only in a very minor way to bladder contraction. Rather, muscarinic-receptor-mediated bladder contraction involves voltage-operated Ca2+ channels and Rho kinase. The prototypical signaling pathway of β-adrenoceptors is an activation of adenylyl cyclase with the subsequent formation of cAMP. Nevertheless, cAMP apparently contributes in a minor way only to β-adrenoceptor-mediated bladder relaxation. BKCa channels may play a greater role in β-adrenoceptor-mediated bladder relaxation. We conclude that apart from muscarinic receptor antagonists and β-adrenoceptor agonists, inhibitors of Rho kinase and activators of BKCa channels may have potential to treat an overactive bladder.
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Lin WY, Rehfuss A, Whitbeck C, Juan YS, Chichester P, Mannikarottu A, Levin RM. Effect of letrozole on urinary bladder function in the female rabbit. BJU Int 2007; 100:1391-5. [PMID: 17850373 DOI: 10.1111/j.1464-410x.2007.07149.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To investigate the effect of letrozole (a potent aromatase inhibitor that effectively inhibit the synthesis of oestrogen) on bladder contraction with changes in morphology and biochemistry. MATERIALS AND METHODS Sixteen female New Zealand white rabbits were separated into four equal groups; groups 1-3 were given oral letrozole for 1, 2 and 3 weeks, and group 4 was given saline and served as the control group. At the end of the medication period each rabbit was anaesthetized and the bladder muscle strips were used for contractile, histological and biochemical studies. RESULTS The concentration of serum oestrogen was significantly lower and testosterone was significantly higher in letrozole-treated rabbits than in the control group. The rabbits treated for 1 week with letrozole showed significant decreases in the contractile responses to electrical field stimulation, ATP and carbachol, but not to KCl. Contractility returned to normal in the rabbits treated for 2 and 3 weeks. Letrozole resulted in an increased volume percentage of collagens and decreased bladder compliance. The volume percentage of the smooth muscle component also changed, with a significant decrease at 1 week and then a gradual increase at 2 and 3 weeks. Contractile dysfunction was absent at 2 and 3 weeks, which was consistent with no change in sarcoplasmic reticulum Ca(2+)-ATPase content or mitochondrial function. CONCLUSIONS The bladder contractility decline in the first week and was restored at 2 and 3 weeks. The present study unexpectedly showed the possibility that testosterone might be as important as oestrogen in the contractile function of the female bladder.
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Affiliation(s)
- Wei-Yu Lin
- Division of Urology, Department of Surgery, Chang Gung Memorial Hospital, Chia-Yi, Taiwan, ROC, and Albany College of Pharmacy, Albany, NY, USA
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Paulis L, Lísková S, Pintérová M, Dobesová Z, Kunes J, Zicha J. Nifedipine-sensitive noradrenergic vasoconstriction is enhanced in spontaneously hypertensive rats: the influence of chronic captopril treatment. Acta Physiol (Oxf) 2007; 191:255-66. [PMID: 17680837 DOI: 10.1111/j.1748-1716.2007.01737.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AIM The relationship between increased sympathetic tone and enhanced activity of L-type voltage-dependent Ca2+ channels (L-VDCC) in spontaneously hypertensive rats (SHR) was studied using in vivo and in vitro approaches. METHODS The effects of acute L-VDCC blockade on sympathetic vasoconstriction or blood pressure (BP) and the contribution of calcium influx to norepinephrine (NE)-induced arterial contraction were investigated in 10-week-old SHR and in age-matched SHR made normotensive by chronic captopril treatment from weaning. RESULTS Blood pressure fall occurring after acute ganglionic or L-VDCC blockade was enhanced in SHR. Ganglionic blockade eliminated strain differences in BP response to acute L-VDCC blockade and vice versa, suggesting that enhanced contribution of L-VDCC is responsible for augmented sympathetic vasoconstriction in SHR. Both phasic (dependent on internal calcium stores) and tonic (dependent on calcium influx) contractions to NE were augmented in SHR femoral arteries in vitro. Nifedipine attenuated only tonic contractions but to a larger extent in SHR than in WKY arteries. Nifedipine effect was greater after endothelium removal, which augmented tonic but not phasic contractions after NE. Chronic captopril treatment of SHR prevented hypertension development by suppression of their sympathetic vasoconstriction including its nifedipine-sensitive component, but failed to influence enhanced NE-induced arterial contractions or increased relaxation to nifedipine in vitro. CONCLUSION The contribution of nifedipine-sensitive component to noradrenergic vasoconstriction is enhanced during excessive NE stimulation (increased sympathetic tone of SHR in vivo or supramaximal NE stimulation in vitro). It seems that captopril-induced reduction of central sympathetic tone is able to normalize augmented nifedipine-sensitive vasoconstriction in SHR.
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Affiliation(s)
- L' Paulis
- Cardiovascular Research Center, Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
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Priviero FBM, Teixeira CE, Toque HAF, Claudino MA, Webb RC, De Nucci G, Zanesco A, Antunes E. Vasorelaxing effects of propranolol in rat aorta and mesenteric artery: a role for nitric oxide and calcium entry blockade. Clin Exp Pharmacol Physiol 2007; 33:448-55. [PMID: 16700877 DOI: 10.1111/j.1440-1681.2006.04386.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
1. Propranolol has been prescribed successfully to patients with cardiovascular diseases, but the exact mechanisms by which it reduces peripheral vascular resistance have been poorly investigated. 2. The present study was designed to investigate the relaxing effects of propranolol in the rat isolated aorta and mesenteric artery, focusing on the contribution of the nitric oxide (NO)-cGMP pathway and calcium entry blockade. Relaxation responses to propranolol were obtained in precontracted rat aortic and mesenteric artery rings. 3. DL-Propranolol (10-100 micromol/L) produced concentration-dependent relaxations in the aorta and mesenteric artery rings with intact endothelium. The isomers D- and L-propranolol produced relaxation responses that were equipotent to the racemic mixture. 4. Metoprolol (10-100 micromol/L) produced slight relaxations, whereas atenolol (10-100 micromol/L) had no relaxant activity. 5. The NO inhibitor N(G)-nitro-L-arginine methyl ester (100 micromol/L) and the soluble guanylate cyclase inhibitor 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (1 micromol/L), as well as removal of the endothelium, significantly reduced the relaxation responses induced by the lower concentrations of propranolol without affecting maximal responses. In addition, DL-propranolol markedly increased cGMP levels in endothelium-intact preparations. 6. In Ca(2+)-free Krebs' solution, DL-propranolol (10-100 micromol/L) caused marked rightward shift in the concentration-response curves to CaCl(2), with a decrease of maximal responses in tissues with either intact or denuded endothelium. Nifedipine (1 micromol/L) in combination with DL-propranolol virtually abolished the CaCl(2)-induced contractile responses. 7. The relaxation responses induced by DL-propranolol were significantly reduced in aortic and mesenteric rings precontracted with phorbol-12,13-dibutyrate (1 micromol/L). 8. In conclusion, DL-propranolol relaxes arterial smooth muscle by mechanisms involving activation of the NO-cGMP pathway and calcium influx blockade, independent of beta-adrenoceptor blockade.
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Affiliation(s)
- Fernanda B M Priviero
- Department of Pharmacology, Faculty of Medical Sciences, State University of Campinas, Campinas, SP, Brazil
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Henze D, Menzel M, Soukup J, Scharf A, Holz C, Németh N, Hanisch F, Clausen T. Endothelin-1 and cerebral blood flow in a porcine model. J Clin Neurosci 2007; 14:650-7. [PMID: 17532501 DOI: 10.1016/j.jocn.2006.05.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2006] [Accepted: 05/30/2006] [Indexed: 11/28/2022]
Abstract
The purpose of the study was to investigate whether provoked changes of cerebral perfusion pressure and arterial carbon dioxide tension are able to influence the cerebral metabolism of endothelin-1 (ET-1) in a porcine model. Brain tissue oxygen tension, regional cerebral blood flow and mean arterial blood pressure were monitored in 10 healthy pigs during induced hyperventilation (HV), hypertension (HrT) and hypotension (HoT). ET-1 was determined in the arterial and cerebrovenous blood. Microdialysis samples (lactate, glucose and pyruvate) were taken from brain and subcutaneous tissue. A significant decrease (p<0.05) of the arterial ET-1 (1.46+/-0.33 fmol/mL) compared to the baseline (2.18+/-0.36 fmol/mL) was observed after the HoT-period. We detected a positive correlation between cerebrovenous ET-1 and extracellular cerebral glucose (0.68; p<0.05) after the baseline as well as a negative correlation of -0.81 (p<0.005) between the cerebrovenous ET-1 level and the extracellular cerebral lactate after the HoT-period. These data imply that with increasingly pathological changes of the cerebral metabolism endothelin becomes progressively more important in the regulation of cerebral vascular tone.
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Affiliation(s)
- Dirk Henze
- Department of Anaesthesiology and Intensive Care Medicine, Martin-Luther-University Halle-Wittenberg, Dryanderstr. 4-7, 06108 Halle (Saale), Germany.
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18
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Yakubu MA, Nsaif RH, Oyekan AO. peroxisome proliferator-activated receptor alpha activation-mediated regulation of endothelin-1 production via nitric oxide and protein kinase C signaling pathways in piglet cerebral microvascular endothelial cell culture. J Pharmacol Exp Ther 2006; 320:774-81. [PMID: 17105827 PMCID: PMC4502983 DOI: 10.1124/jpet.106.104992] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Elevated endothelin (ET)-1 has been implicated in cerebrovascular complications following brain trauma characterized by dysregulation of endothelial nitric oxide synthase (eNOS), protein kinase C (PKC), and cerebral function. Recently, vascular expression of PPARalpha has been observed and suggested to improve vascular dysfunction. We speculate that activation of PPARalpha in cerebral microvessels can improve cerebral dysfunction following trauma, and we tested the hypothesis that activation of cerebral endothelial peroxisome proliferator-activated receptor (PPAR)alpha will attenuate ET-1 production via a mechanism involving nitric oxide (NO) and PKC. Phorbol 12-myristate 13-acetate (PMA) (1 microM), bradykinin (BK, 1 microM), angiotensin II (AII, 1 microM), or hemoglobin (Hem, 10 microM) increased ET-1 levels by 24-, 11.4-, 3.6-, or 1.3-fold increasing ET-1 levels from 0.36 +/- 0.08 to 8.6 +/- 0.8, 4.1 +/- 0.7, 1.30 +/- 0.1, or 0.47 +/- 0.03 fmol/microg protein (p < 0.05), respectively. Clofibrate (10 microM) reduced basal ET-1 from 0.36 +/- 0.08 (control) to 0.03 +/- 0.01 and blunted vasoactive agent-induced increase to 0.12 +/- 0.07 (PMA), 0.6 +/- 0.04 (BK), 0.25 +/- 0.03 (AII), or 0.12 +/- 0.03 (Hem) fM/microg protein (p < 0.05). L-arginine methyl ester (100 microM) inhibited clofibrate-induced reduction in basal ET-1 production. Clofibrate increased PPARalpha expression, accompanied by increased NO production and eNOS expression. PKC inhibition by calphostin C (10 microM) blocked these effects, whereas activation by PMA reduced basal PPARalpha expression. Thus, PPARalpha activation attenuated ET-1 production by agents that mediate brain injury through mechanisms that probably result from PPARalpha-induced increase in eNOS expression/NO production and complex PKC signaling pathways. Therefore, PPARalpha activators can be appropriate therapeutic agents to alleviate cerebrovascular dysfunction following cerebral vasospasm.
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Affiliation(s)
- Momoh A Yakubu
- Vascular Biology Unit, Center for Cardiovascular Diseases, College of Pharmacy and Health Sciences, Texas Southern University, Houston, TX 77004, USA.
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19
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Yakubu MA, Leffler CW. Regulation of cerebral microvascular endothelial cell cyclooxygenase-2 message and activity by blood derived vasoactive agents. Brain Res Bull 2005; 68:150-6. [PMID: 16325014 DOI: 10.1016/j.brainresbull.2005.07.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2005] [Revised: 07/01/2005] [Accepted: 07/04/2005] [Indexed: 12/01/2022]
Abstract
We have investigated the effects of prolonged treatment of cerebral microvascular endothelial cells with vasoconstrictor products of blood clot hemolysis on prostanoid production and cyclooxygenase (COX)/prostacyclin synthase activity and message. Confluent primary cultures of endothelial cells derived from piglet cerebral microvessels were incubated with endothelin-1 (ET-1; 10 nM) or thromboxane A(2) analog U-46619 (1 microM), alone or combined, and COX/prostacyclin synthase activity determined following exposure of treated cells to arachidonic acid (10 microM) for 30 min. 6-KetoPGF(1)alpha and PGE(2) levels in the medium were determined using radioimmunoassay. Effect of treatments on COX-2 message was determined by RNAse Protection Assay. Combined treatment with ET-1 (10 nM) and U-46619 (1 microM) for 24h significantly reduced 6-ketoPGF(1)alpha and PGE(2) levels in the media by 57% and 33%. Treatment of cells with U-46619 alone increased both 6-ketoPGF(1)alpha and PGE(2) level in the media by 170% and 42%. Incubation of control cells with arachidonic acid (10 microM) for 30 min increased 6-ketoPGF(1)alpha and PGE(2) production by 163% and 567%. Pretreatment with ET-1 or U-46619 alone for 24h had no significant effect on 6-ketoPGF(1)alpha produced from exogenous arachidonic acid. However, PGE(2) production from exogenous arachidonic acid by cells pretreated with ET-1 but not with U-46619 was attenuated by 35%. Combined treatment with ET-1 and U-46619 reduced both PGE(2) and 6-ketoPGF(1)alpha production from arachidonic acid by 14% and 40%, respectively. Acute incubation of cells with ET-1 or U-46619 did not have any significant effects on COX-2 mRNA. In conclusion, combined ET-1 and U-46619 reduced prostanoid production. The reduction cannot be fully explained by changes in COX/prostacyclin synthase activity and/or message, but the changes could be due to reduced availability of free arachidonic acid potentially resulting from inhibition of endothelial phospholipase A(2).
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Affiliation(s)
- Momoh A Yakubu
- Vascular Biology Unit, Center for Cardiovascular Diseases, College of Pharmacy and Health Sciences, Texas Southern University, 3100 Cleburne Avenue, Houston, TX 77004, USA.
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20
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Laporte R, Hui A, Laher I. Pharmacological modulation of sarcoplasmic reticulum function in smooth muscle. Pharmacol Rev 2005; 56:439-513. [PMID: 15602008 DOI: 10.1124/pr.56.4.1] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The sarco/endoplasmic reticulum (SR/ER) is the primary storage and release site of intracellular calcium (Ca2+) in many excitable cells. The SR is a tubular network, which in smooth muscle (SM) cells distributes close to cellular periphery (superficial SR) and in deeper aspects of the cell (deep SR). Recent attention has focused on the regulation of cell function by the superficial SR, which can act as a buffer and also as a regulator of membrane channels and transporters. Ca2+ is released from the SR via two types of ionic channels [ryanodine- and inositol 1,4,5-trisphosphate-gated], whereas accumulation from thecytoplasm occurs exclusively by an energy-dependent sarco-endoplasmic reticulum Ca2+-ATPase pump (SERCA). Within the SR, Ca2+ is bound to various storage proteins. Emerging evidence also suggests that the perinuclear portion of the SR may play an important role in nuclear transcription. In this review, we detail the pharmacology of agents that alter the functions of Ca2+ release channels and of SERCA. We describe their use and selectivity and indicate the concentrations used in investigating various SM preparations. Important aspects of cell regulation and excitation-contractile activity coupling in SM have been uncovered through the use of such activators and inhibitors of processes that determine SR function. Likewise, they were instrumental in the recent finding of an interaction of the SR with other cellular organelles such as mitochondria. Thus, an appreciation of the pharmacology and selectivity of agents that interfere with SR function in SM has greatly assisted in unveiling the multifaceted nature of the SR.
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Affiliation(s)
- Régent Laporte
- Ferring Research Institute, Inc., Ferring Pharmaceuticals, San Diego, California, USA
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21
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Daniel EE, Willis A, Cho WJ, Boddy G. Comparisons of neural and pacing activities in intestinal segments from W/W++ and W/W(V) mice. Neurogastroenterol Motil 2005; 17:355-65. [PMID: 15916623 DOI: 10.1111/j.1365-2982.2005.00639.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
We studied pacing and neurotransmission in longitudinal (LM) and circular muscle (CM) in intestine of W/W++ and W/W(V) mice. Electrical field-stimulation (EFS) of nerves in LM segments was more inhibitory in W/W(V) mice than in W/W++ mice. No inhibitory input to CM segments of W/W(V) mice was found. The EFS, after nerve block, entrained segments of both W/W++ and mutant mice with 10 ms pulses, and entrained those of mutant mice more readily at 1 and 3 ms pulses. Pacing with external electrodes did not depend on interstitial cells of Cajal in the myenteric plexus (ICC-MP). 2-Aminoethoxydiphenyl borate (2-APB), putative antagonist at IP3 receptors, store-operated channels and the Sacro-endoplasmic reticulum Ca2+ ATPase pump, reduced frequency and amplitudes of pacing of LM segments from W/W(V) mice as it did in BALB/c mice. Thus, its actions may not require ICC-MP. SKF 96365, a putative inhibitor of store-operated channels, reduced frequencies and amplitudes of intestinal segments in W/W++ mice at 10 or 30 micromol L-1. This resulted from blocking L-Ca2+-channels. Thus, no evidence was found that store-operated channels play a role in pacing. In LM segments of W/W(V), SKF 96365 had no effects on frequency of contractions. We conclude, results from models of severely reduced systems may not be applicable to intact ICC networks.
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Affiliation(s)
- E E Daniel
- Department of Pharmacology, University of Alberta, Edmonton, Canada.
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22
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Moffatt JD, Cocks TM. Pharmacologically distinct intracellular calcium pools regulate tonic and oscillatory responses in porcine thoracic duct. J Cardiovasc Pharmacol 2004; 43:83-92. [PMID: 14668572 DOI: 10.1097/00005344-200401000-00013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The present study investigated the mechanisms by which the thromboxane A2 mimetic U46619 can elicit phasic and tonic contractions in the pig thoracic duct, whereas other agonists like 5-hydroxytryptamine (5-HT) produce tonic contractions only. Tonic contractions in response to either agonist were abolished by the l-type voltage-operated calcium channel (VOCC) inhibitor nifedipine, the store-operated calcium channel inhibitor SKF 96365, the calcium-sensitive chloride channel (ClCa) inhibitor niflumic acid, and by removal of extracellular Cl-. Superimposed phasic responses to U46619 were abolished by only nifedipine. Inhibitors of K+ channels did not prevent phasic contractions to U46619. The IP3 receptor antagonist 2-APB attenuated tonic contractions only, whereas ryanodine and removal of extracellular Na+ selectively abolished phasic contractions to U46619. Therefore, selective initiation of phasic contractions by U46619 appears to depend on intracellular Ca2+ from a ryanodine-sensitive store that causes depolarization via Na+/Ca2+ exchange, whereas tonic contractions to U46619 and 5-HT are mediated primarily by release of IP3-mobilized intracellular Ca2+ that subsequently causes ClCa opening, membrane depolarization, and Ca2+ entry via l-type VOCC.
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Affiliation(s)
- James D Moffatt
- Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia.
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23
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Abreu IC, Marinho ASS, Paes AMA, Freire SMF, Olea RSG, Borges MOR, Borges ACR. Hypotensive and vasorelaxant effects of ethanolic extract from Jatropha gossypiifolia L. in rats. Fitoterapia 2004; 74:650-7. [PMID: 14630169 DOI: 10.1016/j.fitote.2003.07.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The present work was carried out to examine the hypotensive effects of ethanolic extract (EE) from Jatropha gossypiifolia L. The oral administration of EE (125 or 250 mg kg(-1) day(-1)) caused a significant and dose-dependent reduction of the systolic blood pressure. The concentration-response curves to norepinephrine (NE) or Ca(2+) were non-parallelly shifted to the right and the maximum contractile responses were concentration dependently depressed by EE (0.1 or 0.5 mg/ml) in endothelium-deprived mesenteric artery. The cumulative additions of EE (0.1-30 mg/ml) caused a concentration-dependent relaxant response in endothelium-deprived mesenteric artery precontracted with NE or Ca(2+). In conclusion, our results have shown that the EE from J. gossypiifolia L. can elicit hypotension, by oral via, in conscious normotensive rats and vasorelaxant activity on rat mesenteric rings precontracted with NE or Ca(2+).
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Affiliation(s)
- Iracelle C Abreu
- Departamento de Ciências Fisiológicas, Universidade Federal do Maranhão, São Luís, Maranhão 65.085-580, Brazil
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Ajayi AA, Ogungbade GO, Hercule HC, Oyekan AO, Mutembei L. Alteration in endothelin receptor sub-type responsiveness and in the endothelin-TXA(2) mimetic U46619 interaction, in type-2 hypertensive diabetic Zucker rats. Diabetes Res Clin Pract 2004; 63:155-69. [PMID: 14757287 DOI: 10.1016/j.diabres.2003.09.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Type-2 diabetes is characterized by endotheliopathy, which increases target organ damage and mortality. There is excessive endothelin-1 and TXA(2) production, and abnormal vascular reactivity to endothelin-1, manifested as a paradoxical hypotensive action in Zucker diabetic, but not lean rats. We examined the hypothesis that there is an alteration in the ET-A/ET-B receptor subtype sensitivity, and/or the interaction or cross-talk between ET-1 and TXA(2) in type-2 diabetes, using Zucker diabetic rats and their lean littermates. MATERIALS AND METHODS Hemodynamic studies were performed in lean and Zucker fatty diabetic rats of both sexes. Laser doppler flowmetry was used to measure renal cortical (RCF) and medullary blood flow (MBF) responses. Dose response curves for mean arterial blood pressure (MAP), MBF and RCF in response to ET-1, U46619, acetylcholine, and L-NAME (25mg/kg) were constructed after pre-treatment of the rats with either BQ610 1mg/kg i.v. or BQ788 0.5mg/kg i.v. The effects of BQ610 and BQ788 on whole blood impedance aggregation were also assessed. RESULTS BQ788, but not BQ610 abolished both the paradoxical hypotensive action of ET-1 in Zucker diabetic rats (n=7 each, P<0.001 ANOVA) as well as the dose-dependent rise in MBF (P<0.001 ANOVA). BQ788, but not BQ610 abolished the difference in response to ET-1 between lean and diabetic Zucker rats. U46619 caused a hypotensive action in male Zucker rats which was abolished by L-NAME 25mg/kg or indomethacin 10mg/kg i.v. The U46619 interaction with BQ788 on both MAP and MBF was significantly (P<0.03 ANOVA) different between lean and diabetic Zucker rats. BQ788, but not BQ610 attenuated both the MAP and MBF responses to acetylcholine or L-NAME P<0.02 ANOVA). However, BQ610 dose-dependently attenuated the slope of platelet aggregation in both lean and Zucker diabetic rats (P<0.02 ANOVA). CONCLUSION ET-B receptor antagonism abolished the abnormal vascular reactivity and MBF responses to ET-1, and also normalized the vasoactive responses to the level seen in healthy lean Zucker rats. ET-1 receptor blockade influences the responses to TXA(2) receptor activation. In the systemic and renal circulation, this interaction appears to be mostly ET-B receptor mediated, whilst in platelets, ET-A receptor role may be predominant. The interaction or cross-talk between ET-1 and TXA(2) is altered in the type-2 diabetic state. Collectively, these pathophysiological changes may contribute to the vicious circle of diabetic endotheliopathy.
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MESH Headings
- 15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid/pharmacology
- Acetylcholine/pharmacology
- Animals
- Antihypertensive Agents/pharmacology
- Blood Flow Velocity/drug effects
- Blood Pressure/drug effects
- Diabetes Mellitus, Type 2/complications
- Diabetes Mellitus, Type 2/physiopathology
- Drug Interactions
- Endothelin A Receptor Antagonists
- Endothelin B Receptor Antagonists
- Endothelin-1/pharmacology
- Enzyme Inhibitors/pharmacology
- Hypertension/complications
- Hypertension/physiopathology
- Kidney Cortex/blood supply
- Kidney Medulla/blood supply
- Male
- NG-Nitroarginine Methyl Ester/pharmacology
- Oligopeptides/pharmacology
- Piperidines/pharmacology
- Platelet Aggregation/drug effects
- Rats
- Rats, Sprague-Dawley
- Rats, Zucker
- Receptor Cross-Talk
- Receptor, Endothelin A/drug effects
- Receptor, Endothelin A/physiology
- Receptor, Endothelin B/drug effects
- Receptor, Endothelin B/physiology
- Receptors, Endothelin/drug effects
- Receptors, Endothelin/physiology
- Thromboxane A2/pharmacology
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Affiliation(s)
- A A Ajayi
- Center for Cardiovascular Diseases, Texas Southern University, 3100 Cleburne Avenue, Houston, TX 77004, USA.
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25
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Jiang C, Koyabu N, Yonemitsu Y, Shimazoe T, Watanabe S, Naito M, Tsuruo T, Ohtani H, Sawada Y. In vivo delivery of glial cell-derived neurotrophic factor across the blood-brain barrier by gene transfer into brain capillary endothelial cells. Hum Gene Ther 2003; 14:1181-91. [PMID: 12908969 DOI: 10.1089/104303403322168019] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The gene encoding mouse glial cell-derived neurotrophic factor (mGDNF gene) was transfected into brain capillary endothelial cells (BCECs) with the aim of delivering the gene product extensively into the brain parenchyma by making use of the secretory function of BCECs. First, we transfected mGDNF gene into cultured BCECs (MBEC4; mouse brain capillary endothelial cells) in vitro. The amount of mGDNF protein secreted from the transfected cells into the medium was 1500 to 3200 pg/mg of cell protein per day, being about sevenfold higher than that accumulated intracellularly. Furthermore, the basolateral-directed secretion of mGDNF protein from the transfected MBEC4 cells was fivefold higher than the apical-directed secretion. Next, the hemagglutination virus of Japan (HVJ)-liposomes encapsulating mGDNF gene were administered to rats in vivo via the internal carotid artery. The transfected rats showed a marked increase in the brain level of GDNF as assessed by means of enzyme-linked immunosorbent assay (ELISA) and Western blotting on day 3 after the administration, and the level remained significantly elevated for at least 12 days. Furthermore, immunohistochemical staining revealed an increase in GDNF immunoreactivity throughout the transfected forebrain. These results indicate that the gene was successfully transferred in vivo from HVJ-liposomes into BCECs, where it was expressed, and the gene product was secreted into the brain. Then, using this delivery method, we evaluated the protective effect for dopamine neuron against a retrograde 6-hydroxydopamine (6-OHDA) lesion, as assessed by behavioral and neurochemical indices.
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Affiliation(s)
- Chen Jiang
- Department of Medico-Pharmaceutical Sciences, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
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Abstract
During the fetal period, blood is oxygenated through the placenta, and most of the cardiac output bypasses the lung through the ductus arteriosus. At birth, pulmonary vascular resistance falls with the initiation of ventilation. Coincidentally, the ductus arteriosus constricts. Endothelin-1 (ET-1) appears to play an important role during that transition period and postnatally. ET-1 can dramatically increase resistance in the placental microcirculation and may be involved in blood flow redistribution with hypoxia. At birth, the increase in oxygen tension is important in triggering ductus vasoconstriction. It is proposed that oxygen triggers closure of the ductus arteriosus by activating a specific, cytochrome P450-linked reaction, which in turn stimulates the synthesis of ET-1. On the neonatal heart, ET-1 has a positive chronotropic but negative inotropic effect. In the newborn piglet and the fetal lamb, both term and preterm, ET-1 causes a potent, long-lasting pulmonary vasoconstriction. Furthermore, a transient dilator response has been identified, and it is ascribed to nitric oxide formation. ET receptors are abundant in the piglet pulmonary vasculature. They are predominantly of the ETA constrictor subtype, though ETB2 constrictor receptors may also be present in certain species. The dilator response is linked to the ETB1 receptor, and the number of ETB1 receptors is reduced in hypoxia-induced pulmonary hypertension. ET-1 appears to be a causative agent in the pathogenesis of hypoxia- and hyperoxia-induced pulmonary hypertension as demonstrated by reversal of hemodynamic and morphological changes with treatment with an ETA receptor antagonist. Findings are amenable to practical applications in the management of infants with pulmonary hypertension or requiring persistent patency of the ductus arteriosus.
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Affiliation(s)
- Thérèse Perreault
- Newborn Medicine, Department of Pediatrics, The Montreal Children's Hospital, McGill University, 2300 Tupper Street, Montreal, QC H3H 1P3, Canada.
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27
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Abstract
The physiological and pathological importance of lysophosphatidic acid (LPA) in the nervous system is underscored by its presence, as well as the expression of its receptors in neural tissues. In fact, LPA produces responses in a broad range of cell types related to the function of the nervous system. These cell types include neural cell lines, neural progenitors, primary neurons, oligodendrocytes, Schwann cells, astrocytes, microglia, and brain endothelial cells. LPA-induced cell type-specific effects include changes in cell morphology, promotion of cell proliferation and cell survival, induction of cell death, changes in ion conductance and Ca2+ mobilization, induction of pain transmission, and stimulation of vasoconstriction. These effects are mediated through a number of G protein-coupled LPA receptors that activate various downstream signaling cascades. This review provides a current summary of LPA-induced effects in neural cells in vitro or in vivo in combination with our current understanding of the signaling pathways responsible for these effects.
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Affiliation(s)
- Xiaoqin Ye
- Department of Pharmacology, School of Medicine, University of California, San Diego, La Jolla, CA 92093-0636, USA
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28
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Yakubu MA, Leffler CW. L-type voltage-dependent Ca2+ channels in cerebral microvascular endothelial cells and ET-1 biosynthesis. Am J Physiol Cell Physiol 2002; 283:C1687-95. [PMID: 12388093 PMCID: PMC2924154 DOI: 10.1152/ajpcell.00071.2002] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We investigated the role of intracellular calcium concentration ([Ca2+]i) in endothelin-1 (ET-1) production, the effects of potential vasospastic agents on [Ca2+]i, and the presence of L-type voltage-dependent Ca2+ channels in cerebral microvascular endothelial cells. Primary cultures of endothelial cells isolated from piglet cerebral microvessels were used. Confluent cells were exposed to either the thromboxane receptor agonist U-46619 (1 microM), 5-hydroxytryptamine (5-HT; 0.1 mM), or lysophosphatidic acid (LPA; 1 microM) alone or after pretreatment with the Ca2+-chelating agent EDTA (100 mM), the L-type Ca2+ channel blocker verapamil (10 microM), or the antagonist of receptor-operated Ca2+ channel SKF-96365 HCl (10 microM) for 15 min. ET-1 production increased from 1.2 (control) to 8.2 (U-46619), 4.9 (5-HT), or 3.9 (LPA) fmol/microg protein, respectively. Such elevated ET-1 biosynthesis was attenuated by verapamil, EDTA, or SKF-96365 HCl. To investigate the presence of L-type voltage-dependent Ca2+ channels in endothelial cells, the [Ca2+]i signal was determined fluorometrically by using fura 2-AM. Superfusion of confluent endothelial cells with U-46619, 5-HT, or LPA significantly increased [Ca2+]i. Pretreatment of endothelial cells with high K+ (60 mM) or nifedipine (4 microM) diminished increases in [Ca2+]i induced by the vasoactive agents. These results indicate that 1) elevated [Ca2+]i signals are involved in ET-1 biosynthesis induced by specific spasmogenic agents, 2) the increases in [Ca2+]i induced by the vasoactive agents tested involve receptor as well as L-type voltage-dependent Ca2+ channels, and 3) primary cultures of cerebral microvascular endothelial cells express L-type voltage-dependent Ca2+ channels.
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Affiliation(s)
- Momoh A Yakubu
- Laboratory for Research in Neonatal Physiology, Vascular Biology Program, Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee 38163, USA.
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Martin-Nizard F, Furman C, Delerive P, Kandoussi A, Fruchart JC, Staels B, Duriez P. Peroxisome proliferator-activated receptor activators inhibit oxidized low-density lipoprotein-induced endothelin-1 secretion in endothelial cells. J Cardiovasc Pharmacol 2002; 40:822-31. [PMID: 12451315 DOI: 10.1097/00005344-200212000-00003] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Endothelin is a potent vasoconstrictor peptide isolated from endothelial cells and it induces smooth muscle cell proliferation. Endothelin-1 secretion is increased in atheroma and induces deleterious effects such as vasospasm and atherosclerosis. Oxidized low-density lipoproteins (LDLs) induce atherosclerosis in the vascular wall, as well as endothelin-1 secretion in endothelial cells and are activators of both peroxisome proliferator-activated receptor-alpha (PPAR-alpha) and PPAR-gamma. PPAR-alpha (fibric acids) and PPAR-gamma (glitazones) activators are used to treat dyslipoproteinemias and type 2 diabetes, respectively. Furthermore, these drugs induce numerous pleiotropic effects, such as inhibiting thrombin-induced endothelin-1 secretion in endothelial cells. This study shows that both PPAR-alpha (Wy 14643) and PPAR-gamma activation (rosiglitazone) partially inhibit oxidized LDL-induced protein kinase C activity and endothelin-1 secretion in endothelial cells at the transcriptional levels and suggests that synthetic PPAR activators are stronger PPAR activators than oxidized LDL. This study also suggests that fibrate and glitazone treatments should have beneficial effects on the vascular wall by reducing endothelin-1 secretion and the resulting vasospasm and atherosclerosis.
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Affiliation(s)
- F Martin-Nizard
- Department of Research on Lipoproteins and Atherosclerosis, Pasteur Institute, University of Lille, France.
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30
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Diebolt M, Andriantsitohaina R. Wine polyphenols modulate calcium handling in rat aorta: involvement of nitric oxide pathway. Fundam Clin Pharmacol 2002; 16:289-96. [PMID: 12570017 DOI: 10.1046/j.1472-8206.2002.00077.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The effects of short-term oral administration of red wine polyphenolic compounds (RWPCs) on blood pressure and vascular reactivity were investigated in rats. The consequence of RWPCs treatment on agonist-induced contractility of rat aorta with respect to Ca2+ handling was assessed, by examining both intracellular Ca2+ store and extracellular Ca2+ influx components of the response. Rats were treated daily for 7 days by intragastric administration of either 5% glucose, or RWPCs (20 mg/kg) [from two different sources, i.e. Provinols (SFD, Vallont Pont d'Arc, France) and RWPC1 (INRA, Montpellier, France)]. Administration of these compounds produced a decrease in systolic blood pressure. The consequence of RWPCs treatment on vascular smooth muscle was investigated in rat aorta without endothelium exposed to noradrenaline. In Ca(2+)-free medium, RWPC1 but not Provinols treatment induced an increase in noradrenaline-induced contraction. After depletion of intracellular Ca2+ stores by noradrenaline in Ca(2+)-free medium, addition of CaCl2 in the continuous presence of agonist induced an increase in contraction, which was not significantly different between control, Provinols- and RWPC-treated rats. The presence of an inhibitor of sarcoplasmic reticulum Ca(2+)-ATPase, thapsigargin, significantly reduced noradrenaline-induced contraction in Ca(2+)-free medium in RWPCs-treated aorta, as compared to that of control. Interestingly, the inhibitory effect of thapsigargin on the response linked to the release of Ca2+ from internal stores in RWPCs-treated vessels was completely prevented in the presence of NO-synthase inhibitor, L-nitro arginine methyl ester, the inhibitor of guanylyl cyclase, oxadiazolo-quinoxaline or the protein kinase G inhibitor, 8-Bromoguanosine-3'-5-cyclic mono-phosphorothioate, Rp isomer. These results suggest that short-term administration of RWPCs in rats induced subtle alteration of thapsigargin-sensitive component of agonist-induced contraction in rat aorta linked to Ca2+ release from intracellular store. Calcium release from intracellular stores sensitive to thapsigargin was implicated in this mechanism. The prevention of the inhibitory effect of thapsigargin by the inhibitors of NO/cyclic guanosine monophosphate pathway after RWPCs treatment highlights the role of NO in this phenomenon.
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MESH Headings
- Administration, Oral
- Animals
- Aorta, Thoracic/drug effects
- Aorta, Thoracic/metabolism
- Aorta, Thoracic/physiology
- Blood Pressure/drug effects
- Calcium/metabolism
- Cyclic GMP-Dependent Protein Kinases/antagonists & inhibitors
- Dose-Response Relationship, Drug
- Enzyme Inhibitors/pharmacology
- Guanylate Cyclase/antagonists & inhibitors
- In Vitro Techniques
- Male
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/physiology
- NG-Nitroarginine Methyl Ester/pharmacology
- Nitric Oxide/metabolism
- Norepinephrine/pharmacology
- Phenols/pharmacology
- Rats
- Rats, Wistar
- Thapsigargin/pharmacology
- Vasoconstrictor Agents/pharmacology
- Vasodilation/drug effects
- Wine
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Affiliation(s)
- Myriam Diebolt
- Pharmacologie et Physicochimie des Interactions Cellulaires et Moléculaires, CNRS UMR 7034, 67 route du Rhin, Faculté de Pharmacie, 67401 Illkirch, France
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31
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Kobayashi H, Yokoo H, Yanagita T, Wada A. [Regulation of brain microvessel function]. Nihon Yakurigaku Zasshi 2002; 119:281-6, 309. [PMID: 12061139 DOI: 10.1254/fpj.119.281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The brain microvessels are formed by a specialized endothelium and regulate the movement of solutes between blood and brain. The endothelial cells are sealed together by tight junctions and play a role as the blood-brain barrier. The brain microvessels express GLUT1 as the major form of glucose transporter, aquaporin-4 as a water channel, and p-glycoprotein as a xenobiotic transporter. Occludin and claudin-5 have been identified as the components of tight junction. Increasing evidence suggests that the activities of the transporters are regulated by adrenergic nerve activity as well as by bioactive peptides such as adrenomedullin. The regulation of the activity as well as expression of these transporters may become a strategy for prophylaxis and treatment of not only cerebral vascular diseases but also neurodegenerative disorders, developmental abnormalities and aging of the brain.
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Affiliation(s)
- Hideyuki Kobayashi
- Department of Pharmacology, Miyazaki Medical College, 5200 Kihara, Kiyotake, Miyazaki 889-1692, Japan.
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32
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Sercombe R, Dinh YRT, Gomis P. Cerebrovascular inflammation following subarachnoid hemorrhage. JAPANESE JOURNAL OF PHARMACOLOGY 2002; 88:227-49. [PMID: 11949877 DOI: 10.1254/jjp.88.227] [Citation(s) in RCA: 158] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Aneurysmal subarachnoid hemorrhage frequently results in complications including intracranial hypertension, rebleeding and vasospasm. The extravasated blood is responsible for a cascade of reactions involving release of various vasoactive and pro-inflammatory factors (several of which are purported to induce vasospasm) from blood and vascular components in the subarachnoid space. The authors review the available evidence linking these factors to the development of inflammatory lesions of the cerebral vasculature, emphasizing: 1) neurogenic inflammation due to massive release of sensory nerve neuropeptides; 2) hemoglobin from lysed erythrocytes, which creates functional lesions of endothelial and smooth muscle cells; 3) activity, expression and metabolites of lipoxygenases cyclooxygenases and nitric oxide synthases; 4) the possible role of endothelin-1 as a pro-inflammatory agent; 5) serotonin, histamine and bradykinin which are especially involved in blood-brain barrier disruption; 6) the prothrombotic and pro-inflammatory action of complement and thrombin towards endothelium; 7) the multiple actions of activated platelets, including platelet-derived growth factor production; 8) the presence of perivascular and intramural macrophages and granulocytes and their interaction with adhesion molecules; 9) the evolution, origins, and effects of pro-inflammatory cytokines, especially IL-1, TNF-alpha and IL-6. Human and animal studies on the use of anti-inflammatory agents in subarachnoid hemorrhage include superoxide and other radical scavengers, lipid peroxidation inhibitors, iron chelators, NSAIDs, glucocorticoids, and serine protease inhibitors. Many animal studies claim reduced vasospasm, but these effects are not always confirmed in human trials, where symptomatic vasospasm and outcome are the major endpoints. Despite recent work on penetrating vessel constriction, there is a paucity of studies on inflammatory markers in the microcirculation.
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Affiliation(s)
- Richard Sercombe
- Laboratoire de Recherches Cérébrovasculaires, CNRS UPR 646, IFR Circulation Lariboisière, Université Paris VI, Faculté de Médecine Lariboisière-St Louis, Paris, France.
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33
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Fang LH, Kwon SC, Zhang YH, Ahn HY. Tyrosine kinase participates in vasoconstriction through a Ca(2+)- and myosin light chain phosphorylation-independent pathway. FEBS Lett 2002; 512:282-6. [PMID: 11852096 DOI: 10.1016/s0014-5793(02)02235-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
This study was undertaken to determine the role of tyrosine kinase on intracellular Ca(2+) ([Ca(2+)](i)), myosin light chain (MLC) phosphorylation, and contraction caused by norepinephrine (NE) in rat aorta. NE induced a sustained contraction with an increase of [Ca(2+)](i). On the other hand, NE increased the phosphorylation of the 20 kDa MLC transiently. Pretreatment with genistein and tyrophostin 25, tyrosine kinase inhibitors, significantly inhibited NE-induced contraction, but did not affect the increase of [Ca(2+)](i) and MLC phosphorylation. These results suggest that tyrosine kinase may regulate the NE-mediated contraction without altering [Ca(2+)](i) and MLC phosphorylation in rat aorta.
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Affiliation(s)
- Lian Hua Fang
- Department of Pharmacology, College of Medicine, Chungbuk National University, 361-763, Cheongju, South Korea
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34
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Abstract
Twenty-five years after the discovery of protein kinase C (PKC), the physiologic function of PKC, and especially its role in pathologic conditions, remains a subject of great interest with 30,000 studies published on these aspects. In the cerebral circulation, PKC plays a role in the regulation of myogenic tone by sensitization of myofilaments to calcium. Protein kinase C phosphorylates various ion channels including augmenting voltage-dependent Ca2+ channels and inhibiting K+ channels, which both lead to vessel contraction. These actions of PKC amplify vascular reactivity to different agonists and may be critical in the regulation of cerebral artery tone during vasospasm. Evidence accumulated during at least the last decade suggest that activation of PKC in cerebral vasospasm results in a delayed but prolonged contraction of major arteries after subarachnoid hemorrhage. Most of the experimental results in vitro or in animal models support the view that PKC is involved in cerebral vasospasm. Implication of PKC in cerebral vasospasm helps explain increased arterial narrowing at the signal transduction level and alters current perceptions that the pathophysiology is caused by a combination of multiple receptor activation, hemoglobin toxicity, and damaged neurogenic control. Activation of protein kinase C also interacts with other signaling pathways such as myosin light chain kinase, nitric oxide, intracellular Ca2+, protein tyrosine kinase, and its substrates such as mitogen-activated protein kinase. Even though identifying PKC revolutionized the understanding of cerebral vasospasm, clinical advances are hampered by the lack of clinical trials using selective PKC inhibitors.
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Affiliation(s)
- I Laher
- Department of Pharmacology & Therapeutics, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
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35
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Li HF, Zheng TZ, Li W, Qu SY, Zhang CL. Effect of progesterone on the contractile response of isolated pulmonary artery in rabbits. Can J Physiol Pharmacol 2001. [DOI: 10.1139/y01-024] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The purpose of this study was to assess the direct effect of progesterone on rabbit pulmonary arteries and to examine the mechanism of its action. Rings of pulmonary artery from male rabbits were suspended in organ baths containing Krebs solution, and isometric tension was measured. The response to progesterone was investigated in arterial rings contracted with noradrenaline (NA), KCl, and CaCl2. The effects of endothelium, nitric oxide(NO), prostaglandins, cyclic GMP(cGMP), and the adrenergic β-receptor on progesterone-induced relaxation were also assessed. Progesterone inhibited the vasocontractivity to NA, KCl, and CaCl2, and relaxed rabbit pulmonary artery. The relaxing response of progesterone in pulmonary artery was significantly reduced by removal of endothelium, inhibitors of nitric oxide synthase and guanylate cyclase, but not by prostaglandin synthase inhibitor and blockage of the adrenergic β-receptor. In Ca2+-free (0.1 mM EGTA) Krebs solution, progesterone inhibited NA-induced contraction that was intracellular Ca2+-dependent, but didn't affect the contraction of extracellular Ca2+-dependent component. Our results suggest that progesterone induces relaxation of isolated rabbit pulmonary arteries partially via NO and cGMP. Progesterone may also inhibit Ca2+ influx through potential-dependent calcium channels (PDCs) and Ca2+ release from intracellular stores.Key words: progesterone, pulmonary artery, Ca2+ channel, endothelium.
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36
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Ratner AJ, Bryan R, Weber A, Nguyen S, Barnes D, Pitt A, Gelber S, Cheung A, Prince A. Cystic fibrosis pathogens activate Ca2+-dependent mitogen-activated protein kinase signaling pathways in airway epithelial cells. J Biol Chem 2001; 276:19267-75. [PMID: 11278360 DOI: 10.1074/jbc.m007703200] [Citation(s) in RCA: 139] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Much of the pulmonary disease in cystic fibrosis is associated with polymorphonuclear leukocyte-dominated airway inflammation caused by bacterial infection. Respiratory epithelial cells express the polymorphonuclear chemokine interleukin-8 (IL-8) in response to ligation of asialylated glycolipid receptors, which are increased on damaged or regenerating cells and those with cystic fibrosis transmembrane conductance regulator mutations. Because both Pseudomonas aeruginosa and Staphylococcus aureus, the most common pathogens in cystic fibrosis, bind asialylated glycolipid receptors such as asialoGM1, we postulated that diverse bacteria can activate a common epithelial signaling pathway to elicit IL-8 expression. P. aeruginosa PAO1 but not pil mutants and S. aureus RN6390 but not the agr mutant RN6911 stimulated increases in [Ca(2+)](i) in 1HAEo- airway epithelial cells. This response stimulated p38 and ERK1/2 mitogen-activated protein kinase (MAPK) signaling cascades resulting in NF-kappaB activation and IL-8 expression. Ligation of the asialoGM1 receptor or thapsigargin-elicited Ca(2+) release activated this pathway, whereas P. aeruginosa lipopolysaccharide did not. The rapid kinetics of epithelial activation precluded bacterial invasion of the epithelium. Recognition of asialylated glycolipid receptors on airway epithelial cells provides a common pathway for Gram-positive and Gram-negative organisms to initiate an epithelial inflammatory response.
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Affiliation(s)
- A J Ratner
- College of Physicians & Surgeons, Columbia University, New York, New York 10032, USA
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37
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Bertsch T, Kuehl S, Muehlhauser F, Walter S, Hodapp B, Rossol S, Schmeck J, Ragoschke A, Schütt S, Fritzinger M, Horn P, Vajkoczy P, Wellner MW, Fassbender K. Source of endothelin-1 in subarachnoid hemorrhage. Clin Chem Lab Med 2001; 39:341-5. [PMID: 11388659 DOI: 10.1515/cclm.2001.053] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Endothelin-1 is the most potent vasoconstrictor known to date. This peptide is believed to play a pathophysiological role in the development of vasospasm, the most important complication of subarachnoid hemorrhage (SAH). In the present study we investigated the release of endothelin-1 in SAH and analyzed the cellular source of this peptide. At a protein and mRNA level we were able to show that endothelin-1 is produced by mononuclear leukocytes. Complementary in vitro studies revealed that aging and subsequent hemolysis of blood is sufficient to induce production of endothelin-1 by mononuclear leukocytes. Thus, cerebrospinal fluid-derived mononuclear leukocytes are a source of endothelin-1 in patients suffering from SAH. This finding may have important therapeutic implications as anti-leukocyte strategies could prevent cerebrovascular complications in SAH patients.
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Affiliation(s)
- T Bertsch
- Department of Clinical Chemistry, Clinic Mannheim, University of Heidelberg, Germany
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38
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Abstract
To clarify the mechanism underlying increased endothelin-1 release in diabetic rats, we examined its release from thoracic aortas obtained from streptozotocin-induced diabetic rats. The methoxamine-induced contraction was significantly inhibited by BQ-123 plus BQ-788 (specific antagonists for ET(A) and ET(B) receptors) in diabetic, but not control rats. Preincubation with phosphoramidon also inhibited the methoxamine-induced contraction in diabetic but not control rats. The expression of prepro endothelin-1 mRNA was significantly enhanced in aortas from streptozotocin-induced diabetic rats. These results suggest that the increases in the basal and alpha-agonist-induced release of endothelin-1 in the diabetic state may be due to an overexpression of the mRNA for prepro endothelin-1.
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Affiliation(s)
- A Makino
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University, Shinagawa-ku, 142-8501, Tokyo, Japan
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39
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Tigyi G. Physiological responses to lysophosphatidic acid and related glycero-phospholipids. Prostaglandins Other Lipid Mediat 2001; 64:47-62. [PMID: 11324707 DOI: 10.1016/s0090-6980(01)00107-1] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
1-Acyl-2-hydroxy(lyso)-sn-glycero-3-phosphate (lysophosphatidic acid, LPA) has attracted a lot of attention in recent years due to the wide range of its biological effects that span the phylogenetic tree from slime mold to human. LPA can be viewed as a pleiotropic phospholipid growth factor that utilizes the same signal transduction mechanisms as traditional polypeptide growth factors; however, LPA activates these mechanism via specific G protein-coupled receptors. The concentration of LPA in serum is in the high micromolar range, making it the most abundant mitogen/survival factor present in serum, one that is often unknowingly utilized in tissue culture. The present review gives a historical perspective and a critical analysis of the LPA literature with a special emphasis on the physiological implications of its effects.
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Affiliation(s)
- G Tigyi
- Department of Physiology, University of Tennessee Health Sciences Center Memphis, 38163, USA.
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40
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Levin RM, Haugaard N, O'Connor L, Buttyan R, Das A, Dixon JS, Gosling JA. Obstructive response of human bladder to BPH vs. rabbit bladder response to partial outlet obstruction: a direct comparison. Neurourol Urodyn 2001; 19:609-29. [PMID: 11002303 DOI: 10.1002/1520-6777(2000)19:5<609::aid-nau7>3.0.co;2-h] [Citation(s) in RCA: 193] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- R M Levin
- Division of Basic and Pharmaceutical Sciences, Albany College of Pharmacy, Albany, New York 12208, USA.
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41
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Fassbender K, Hodapp B, Rossol S, Bertsch T, Schmeck J, Schütt S, Fritzinger M, Horn P, Vajkoczy P, Wendel-Wellner M, Ragoschke A, Kuehl S, Brunner J, Schürer L, Schmiedeck P, Hennerici M. Endothelin-1 in subarachnoid hemorrhage: An acute-phase reactant produced by cerebrospinal fluid leukocytes. Stroke 2000; 31:2971-5. [PMID: 11108758 DOI: 10.1161/01.str.31.12.2971] [Citation(s) in RCA: 119] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE The most potent vasoconstrictor known, endothelin-1, is currently considered to mediate cerebral vasospasm in subarachnoid hemorrhage (SAH), which can cause delayed cerebral ischemia. In our study, we performed clinical and in vitro experiments to investigate the origin and the mechanisms of the secretion of endothelin-1 in SAH. METHODS Endothelin-1 and markers of inflammatory host response (interleukin [IL]-1ss, IL-6, and tumor necrosis factor-alpha) were comparatively quantified in the cerebrospinal fluid (CSF) of SAH patients and control subjects, and concentrations were related to clinical characteristics. Furthermore, mononuclear leukocytes isolated from the CSF of SAH patients and control subjects were analyzed regarding their mRNA expression of endothelin-1 and inflammatory cytokines. Finally, complementary in vitro experiments were performed to investigate whether coincubation of blood and CSF can trigger leukocytic mRNA expression and release of these factors. RESULTS Activated mononuclear leukocytes in the CSF of SAH patients synthesize and release endothelin-1 in parallel with known acute-phase reactants (IL-1ss, IL-6, and tumor necrosis factor-alpha). Complementary in vitro experiments not only further confirmed this leukocytic origin of endothelin-1 but also showed that aging and subsequent hemolysis of blood is sufficient to induce such endothelin-1 production. CONCLUSIONS The demonstration that endothelin-1 is produced by activated CSF mononuclear leukocytes suggests that subarachnoid inflammation may represent a therapeutic target to prevent vasospasm and delayed cerebral ischemia after SAH.
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Affiliation(s)
- K Fassbender
- Department of Neurology, Clinic Mannheim, University of Heidelberg, Germany.
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42
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Kobayashi H, Minami S, Yamamoto R, Masumoto K, Yanagita T, Uezono Y, Tsuchiya K, Mohri M, Kitamura K, Eto T, Wada A. Adrenomedullin receptors in rat cerebral microvessels. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 2000; 81:1-6. [PMID: 11000473 DOI: 10.1016/s0169-328x(00)00148-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
To characterize the sites of action of adrenomedullin (AM) in the cerebral microvasculature, we studied the effect of AM on cyclic AMP (cAMP) level as well as expression of AM and its receptor in the rat cerebral microvessels. The microvessels were prepared from rat cerebral cortex by albumin flotation and glass bead filtration technique. AM and calcitonin gene-related peptide (CGRP) increased cAMP level in the microvessels in a concentration-dependent manner. The effect of AM was more than 100 times more potent than that of CGRP. The accumulation of cAMP by AM was inhibited by AM[22-52], an AM receptor antagonist, but not by CGRP[8-37], a CGRP receptor antagonist, suggesting that AM increased cAMP accumulation by acting on receptors specific to AM. [125I]AM binding to the microvessels was displaced by AM and less potently by AM[22-52]. The displacing potencies of CGRP and CGRP[8-37] were very weak. mRNAs for AM as well as calcitonin-receptor-like receptor and receptor-activity-modifying protein 2 which form a receptor specific to AM, were highly expressed in the microvessels. These results provide biochemical and pharmacological evidence that AM is produced in and acts on the cerebral microvessels in an autocrine/paracrine manner and is involved in regulation of cerebral microcirculation.
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Affiliation(s)
- H Kobayashi
- Department of Pharmacology, Miyazaki Medical College, 5200 Kihara, Kiyotake, Miyazaki 889-1692, Japan.
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43
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Coceani F, Kelsey L. Endothelin-1 release from the lamb ductus arteriosus: are carbon monoxide and nitric oxide regulatory agents? Life Sci 2000; 66:2613-23. [PMID: 10883739 DOI: 10.1016/s0024-3205(00)00595-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We have proposed that endothelin-1 (ET-1), formed through the activation of a cytochrome P450 (CYP450)-based monooxygenase reaction, is important for generation of contractile tone in the ductus arteriosus and, consequently, for closure of the vessel at birth. The present investigation was undertaken to ascertain, using an isolated ductus preparation from near-term fetal lambs, whether carbon monoxide (CO) and nitric oxide (NO) qualify as regulators of the CYP450/ET-1 system. Preparations released ET-1 at rest and its amount showed no significant reduction following removal of the endothelium. Basal release was not changed by the NO synthesis inhibitor, N(G)-nitro-L-arginine methylester (L-NAME, 100 microM), nor by agents altering cyclic GMP content (i.e. increase; ONO-1505, 1 microM) and action (i.e. decrease; LY-83583, 10 microM). These findings extend previous work showing no effect of the CO synthesis inhibitor zinc protoporphyrin IX (ZnPP, 10 microM) under the same conditions (10). Conversely, both CO (65 microM) and the NO donor, sodium nitroprusside (SNP, 10 microM), curtailed ET-1 release. ET-1 release was increased by oxygen and reduced by pyrogens (endotoxin and IL-1, both at 100 ng mL(-1)). The endotoxin effect tended to be reversed by L-NAME and ZnPP, used singly or in combination. We conclude that ET-1 is formed naturally in the ductus and that its formation may change in response to physiological (oxygen) and pathophysiological (pyrogens) stimuli. Endogenous CO and NO, however, appear to have little or no role as ET-1 regulators.
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Affiliation(s)
- F Coceani
- Integrative Biology Programme, Research Institute, The Hospital for Sick Children, Toronto, Ont., Canada.
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44
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Yakubu MA, Leffler CW. Enhanced pial arteriolar sensitivity to bioactive agents following exposure to endothelin-1. Life Sci 2000; 66:307-16. [PMID: 10665982 DOI: 10.1016/s0024-3205(99)00592-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Effects of prior exposure of pial arterioles to endothelin-1 (ET-1) (10(-9) M) on the constriction induced by the by-products of hemolyzed blood (5-HT, LTC4, LPA, and thromboxane analog U-46619) were examined. Piglets (age: 1-3 d) anesthetized with a mixture of ketamine hydrochloride and acepromazine were implanted with cranial windows, and anesthesia was maintained with alpha-chloralose. Topical applications of the by-products of hemolyzed blood mildly constricted pial arterioles. Following prior exposure of the microvessels to ET-1, application of the by-products of hemolyzed blood produced significantly potentiated and long-lasting constrictions compared to the controls. In another experiment, pretreatment of pial arterioles with U-46619 (10(-8) M) also potentiated the constriction induced by ET-1. The constriction produced was fast and longer-lasting. Thus, these data show that by-products of hemolyzed blood, though not potent vasoconstrictors per se, potently constricted pial arterioles in the presence of ET-1. The same agents in the CSF can also potentiate constriction induced by ET-1. Hence, by-products of hemolyzed blood may play a significant role in the initiation and maintenance of cerebral arterial narrowing observed following intracranial bleeding.
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Affiliation(s)
- M A Yakubu
- Department of Physiology, Cardiovascular Renal Center, The University of Tennessee, Memphis 38163, USA.
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