1
|
Britto-Júnior J, Furlaneto R, Lima AT, de Oliveira MG, Severino B, Frecentese F, Fiorino F, Caliendo G, Muscará MN, De Nucci G. GKT137831 and hydrogen peroxide increase the release of 6-nitrodopamine from the human umbilical artery, rat-isolated right atrium, and rat-isolated vas deferens. Front Pharmacol 2024; 15:1348876. [PMID: 38645555 PMCID: PMC11026650 DOI: 10.3389/fphar.2024.1348876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2023] [Accepted: 02/01/2024] [Indexed: 04/23/2024] Open
Abstract
Introduction: The human umbilical artery (HUA), rat-isolated right atrium, and rat-isolated vas deferens present a basal release of 6-nitrodopamine (6-ND). The basal release of 6-ND from these tissues was significantly decreased (but not abolished) when the tissues were pre-incubated with Nω-nitro-L-arginine methyl ester (L-NAME). Methods: In this study, the effect of the pharmacological modulation of the redox environment on the basal release of 6-ND was investigated. The basal release of 6-ND was measured using Liquid chromatography with tandem mass spectrometry (LC-MS/MS). Results and Discussion: Pre-incubation (30 min) of the tissues with GKT137831 (1 μM) caused a significant increase in the basal release of 6-ND from all tissues. In the HUA, pre-incubation with diphenyleneiodonium (DPI) (100 μM) also caused significant increases in the basal release of 6-ND. Preincubation of the HUA with hydrogen peroxide (H2O2) (100 μM) increased 6-ND basal release, whereas pre-incubation with catalase (1,000 U/mL) significantly decreased it. Pre-incubation of the HUA with superoxide dismutase (SOD) (250 U/mL; 30 min) also significantly increased the basal release of 6-ND. Preincubation of the HUA with either allopurinol (100 μM) or uric acid (1 mM) had no effect on the basal release of 6-ND. Pre-treatment of the HUA with L-NAME (100 μM) prevented the increase in the basal release of 6-ND induced by GKT137831, diphenyleneiodonium, and H2O2. The results obtained indicate a major role of endogenous H2O2 and peroxidases as modulators of 6- ND biosynthesis/release and a lack of peroxynitrite contribution.
Collapse
Affiliation(s)
- José Britto-Júnior
- Department of Pharmacology, Faculty of Medical Sciences, University of Campinas (UNICAMP), Campinas, Brazil
| | - Rafael Furlaneto
- Department of Pharmacology, Faculty of Medical Sciences, University of Campinas (UNICAMP), Campinas, Brazil
- Department of Pharmacology, Faculty of Medicine, Sao Leopoldo Mandic, Campinas, São Paulo, Brazil
| | - Antonio Tiago Lima
- Department of Pharmacology, Faculty of Medical Sciences, University of Campinas (UNICAMP), Campinas, Brazil
| | | | - Beatrice Severino
- Department of Pharmacy, School of Medicine, University of Naples Federico II, Naples, Italy
| | - Francesco Frecentese
- Department of Pharmacy, School of Medicine, University of Naples Federico II, Naples, Italy
| | - Ferdinando Fiorino
- Department of Pharmacy, School of Medicine, University of Naples Federico II, Naples, Italy
| | - Giuseppe Caliendo
- Department of Pharmacy, School of Medicine, University of Naples Federico II, Naples, Italy
| | - Marcelo Nicolás Muscará
- Department of Pharmacology, Institute of Biomedical Sciences, University of São Paulo (USP), Sāo Paulo, Brazil
| | - Gilberto De Nucci
- Department of Pharmacology, Faculty of Medical Sciences, University of Campinas (UNICAMP), Campinas, Brazil
- Department of Pharmacology, Institute of Biomedical Sciences, University of São Paulo (USP), Sāo Paulo, Brazil
- Department of Pharmacology, Faculty of Medicine, Sao Leopoldo Mandic, Campinas, São Paulo, Brazil
| |
Collapse
|
2
|
Uhelski ML, Johns ME, Horrmann A, Mohamed S, Sohail A, Khasabova IA, Simone DA, Banik RK. Adverse effects of methylene blue in peripheral neurons: An in vitro electrophysiology and cell culture study. Mol Pain 2022; 18:17448069221142523. [PMID: 36408567 PMCID: PMC9730009 DOI: 10.1177/17448069221142523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Methylene blue (MB) is an effective treatment for methemoglobinemia, ifosfamide-induced encephalopathy, cyanide poisoning, and refractory vasoplegia. However, clinical case reports and preclinical studies indicate potentially neurotoxic activity of MB at certain concentrations. The exact mechanisms of MB neurotoxicity are not known, and while the effects of MB on neuronal tissue from different brain regions and myenteric ganglia have been examined, its effects on primary afferent neurons from dorsal root ganglia (DRG) have not been studied. Mouse DRG were exposed to MB (0.3-10 μM) in vitro to assess neurite outgrowth. Increasing concentrations of MB (0.3-10 μM) were associated with neurotoxicity as shown by a substantial loss of cells with neurite formation, particularly at 10 μM. In parallel experiments, cultured rat DRG neurons were treated with MB (100 μM) to examine how MB affects electrical membrane properties of small-diameter sensory neurons. MB decreased peak inward and outward current densities, decreased action potential amplitude, overshoot, afterhyperpolarization, increased action potential rise time, and decreased action potential firing in response to current stimulation. MB induced dose-dependent toxicity in peripheral neurons, in vitro. These findings are consistent with studies in brain and myenteric ganglion neurons showing increased neuronal loss and altered membrane electrical properties after MB application. Further research is needed to parse out the toxicity profile for MB to minimize damage to neuronal structures and reduce side effects in clinical settings.
Collapse
Affiliation(s)
- Megan L Uhelski
- Department of Pain Medicine, The University of Texas M.D. Anderson Cancer Center, Houston, TX, USA
| | - Malcolm E Johns
- Department of Anesthesiology, School of Medicine, University of Minnesota, Minneapolis, MN, USA
| | - Alec Horrmann
- Department of Anesthesiology, School of Medicine, University of Minnesota, Minneapolis, MN, USA
| | - Sadiq Mohamed
- Department of Anesthesiology, School of Medicine, University of Minnesota, Minneapolis, MN, USA
| | - Ayesha Sohail
- Department of Anesthesiology, School of Medicine, University of Minnesota, Minneapolis, MN, USA
| | - Iryna A Khasabova
- Department of Diagnostic and Biological Sciences, School of Dentistry, University of Minnesota, Minneapolis, MN, USA
| | - Donald A Simone
- Department of Diagnostic and Biological Sciences, School of Dentistry, University of Minnesota, Minneapolis, MN, USA
| | - Ratan K Banik
- Department of Anesthesiology, School of Medicine, University of Minnesota, Minneapolis, MN, USA,Ratan K Banik, Department of Anesthesiology, University of Minnesota, B515 Mayo Memorial Building, 420 Delaware Street S.E., MMC 294, Minneapolis, MN 55455, USA.
| |
Collapse
|
3
|
Bassiouni W, Senbel A, Norel X, Daabees T. Sildenafil corrects the increased contractility of rat detrusor muscle induced by alprostadil in vitro. Pharmacol Rep 2019; 71:659-668. [PMID: 31195343 DOI: 10.1016/j.pharep.2019.03.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 02/09/2019] [Accepted: 03/11/2019] [Indexed: 01/09/2023]
Abstract
BACKGROUND Sildenafil (PDE5-inhibitor) and alprostadil (PGE1) are used in combination clinically for the management of some cases of erectile dysfunction. Despite the roles of prostaglandins (PG) and nitric oxide (NO) pathways in contractility of bladder smooth muscle are frequently studied, the effect of sildenafil/alprostadil combination and the crosstalk between NO/cGMP and PG pathways on bladder activity is not documented. METHODS Organ-bath experiments were performed using isolated rat detrusor muscle. Direct and neurogenic contractions were induced using ACh and electric stimulation (EFS, 4Hz, 80V, 1ms), respectively. The contractile responses in absence and presence of the tested drugs at different concentrations were compared. Results are expressed as mean ± SEM (n = 5-7). RESULTS Alprostadil (0.01-10 μM) concentration-dependently potentiated ACh (100μM)- and EFS (4 Hz)- induced contraction. Maximum potentiation of ACh-contraction in presence of alprostadil was 40 ± 5%. Sildenafil potentiated ACh-induced contraction at low concentrations (0.01-1 μM), but inhibited it at higher ones (10-100 μM). IBMX (non-selective PDE-inhibitor, 0.01-100μM) and SNP (NO-donor, 1nM-1 mM) produced the same biphasic pattern. The potentiatory phase of sildenafil was inhibited by atropine (0.1μM), L-NAME (non-selective NOS-inhibitor, 100μM), N-PLA (nNOS-inhibitor, 30μM) or MB (nonselective GC-inhibitor, 10μM). In presence of sildenafil (0.1μM), the concentration-response curve of alprostadil (0.01-10μM) on both ACh and EFS-induced contraction was clearly shifted downward. CONCLUSIONS A crosstalk between PGE1 and NO/cGMP pathways may exist. At low concentrations only, the effect of sildenafil on bladder contractility is dependent on NO/cGMP. cGMP intracellularly-elevated by sildenafil, may inhibit the activity of PLC and hence the cascade of EP1-receptors, thus masking the hyperactivity of bladder caused by alprostadil, which adds to the advantages of this combination.
Collapse
Affiliation(s)
- Wesam Bassiouni
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Alexandria University, Egypt
| | - Amira Senbel
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Alexandria University, Egypt; Laboratory for Vascular Translational Sciences, INSERM U1148, X. Bichat Hospital, University Paris XIII, France.
| | - Xavier Norel
- Laboratory for Vascular Translational Sciences, INSERM U1148, X. Bichat Hospital, University Paris XIII, France
| | - Tahia Daabees
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Alexandria University, Egypt
| |
Collapse
|
4
|
Huang C, Tong L, Lu X, Wang J, Yao W, Jiang B, Zhang W. Methylene Blue Attenuates iNOS Induction Through Suppression of Transcriptional Factor Binding Amid iNOS mRNA Transcription. J Cell Biochem 2015; 116:1730-40. [DOI: 10.1002/jcb.25132] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Accepted: 02/06/2015] [Indexed: 12/26/2022]
Affiliation(s)
- Chao Huang
- Department of Pharmacology; School of Pharmacy; Nantong University; #19 Qixiu Road Nantong Jiangsu Province 226001 China
| | - Lijuan Tong
- Department of Pharmacology; School of Pharmacy; Nantong University; #19 Qixiu Road Nantong Jiangsu Province 226001 China
| | - Xu Lu
- Department of Pharmacology; School of Pharmacy; Nantong University; #19 Qixiu Road Nantong Jiangsu Province 226001 China
| | - Jia Wang
- Department of Pharmacology; School of Pharmacy; Nantong University; #19 Qixiu Road Nantong Jiangsu Province 226001 China
| | - Wenjuan Yao
- Department of Pharmacology; School of Pharmacy; Nantong University; #19 Qixiu Road Nantong Jiangsu Province 226001 China
| | - Bo Jiang
- Department of Pharmacology; School of Pharmacy; Nantong University; #19 Qixiu Road Nantong Jiangsu Province 226001 China
| | - Wei Zhang
- Department of Pharmacology; School of Pharmacy; Nantong University; #19 Qixiu Road Nantong Jiangsu Province 226001 China
| |
Collapse
|
5
|
França-Silva MS, Monteiro MMO, Queiroz TM, Santos AF, Athayde-Filho PF, Braga VA. The new nitric oxide donor 2-nitrate-1,3-dibuthoxypropan alters autonomic function in spontaneously hypertensive rats. Auton Neurosci 2012; 171:28-35. [PMID: 23141524 DOI: 10.1016/j.autneu.2012.10.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2012] [Revised: 09/11/2012] [Accepted: 10/12/2012] [Indexed: 10/27/2022]
Abstract
Previously, we found that the nitrate synthesized from glycerin, 2-nitrate-1,3-dibuthoxypropan (NDBP), increased NO levels in rat aortic smooth muscle cells, inducing vasorelaxation in mesenteric artery. However, its effects on blood pressure and heart rate as well as on autonomic function were not investigated. This study evaluated the action of NDBP on these cardiovascular parameters in spontaneously hypertensive (SHR) and Wistar Kyoto (WKY) rats. We found that NDBP causes a biphasic response: hypotension and bradycardia followed by hypertension and tachycardia in WKY and SHR rats. Atropine (2mg/kg) blunted the hypotension induced by NDBP (15 mg/kg) in WKY and SHR (-75 ± 9 vs -12 ± 3 mmHg, n=6; -101 ± 6 vs -7 ± 2 bpm, n=6; respectively, p<0.05) and the pressor response to the compound was potentiated. Furthermore, vagotomy reduced the bradycardia in WKY and SHR (-136 ± 8 vs -17 ± 2, n=4, p<0.05; -141 ± 9 vs -8 ± 2, n=6, p<0.05). Moreover, hexamethonium (30 mg/kg) reduced both bradycardia (-278 ± 23 vs -48 ± 3 in WKY; -285 ± 16 vs -27 ± 19 in SHR, n=4; p<0.05) and pressor response (28 ± 8 vs -9 ± 5-WKY, n=6; 42 ± 7 vs -19 ± 8-SHR, n=5; p<0.05). In addition, administration of methylene blue (4 mg/kg) attenuated the hypotensive and bradycardic responses to the NDBP in all groups. In conclusion, NDBP induces bradycardia by direct vagal stimulation and pressor response by increasing sympathetic outflow to the periphery.
Collapse
|
6
|
Ameer OZ, Salman IM, Siddiqui MJA, Yam MF, Sriramaneni RN, Mohamed AJ, Sadikun A, Ismail Z, Shah AM, Asmawi MZ. Pharmacological mechanisms underlying the vascular activities of Loranthus ferrugineus Roxb. in rat thoracic aorta. JOURNAL OF ETHNOPHARMACOLOGY 2010; 127:19-25. [PMID: 19808083 DOI: 10.1016/j.jep.2009.09.057] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2009] [Revised: 09/09/2009] [Accepted: 09/27/2009] [Indexed: 05/28/2023]
Abstract
AIM OF THE STUDY The present study was aimed to investigate the pharmacological basis for the use of Loranthus ferrugineus in hypertension. MATERIALS AND METHODS Loranthus ferrugineus methanol extract (LFME) was obtained using Soxhelt extractor and then successively fractionated using chloroform, ethyl acetate and n-butanol. The n-butanol fraction of LFME (NBF-LFME) was studied using isolated rat thoracic aorta. RESULTS NBF-LFME (1.0 x 10(-5) to 3.0mg/ml) was found to be the most potent to concentration-dependently relax the endothelium-intact phenyephrine (PE, 1 microM)- and high K(+) (80 mM)-precontracted rat aortic rings. Removal of the endothelium completely abolished the vascular relaxing properties of NBF-LFME. Pretreatment with atropine (1 microM), L-NAME (10 microM), indomethacin (10 microM) and methylene blue (10 microM) significantly blocked NBF-LFME-mediated relaxation. Endothelium-dependent and -independent relaxations induced by acetylcholine (ACh) and sodium nitroprusside (SNP), respectively, were significantly enhanced in aortic rings pretreated with NBF-LFME when compared to those observed in control aortic rings. On the contrary, glibenclamide (10 microM), propranolol (1 microM) and prazosin (0.01 microM) did not alter NBF-LFME-induced relaxation. CONCLUSIONS The results suggest that NBF-LFME induced vascular relaxation by stimulating muscarinic receptors, activating the endothelium-derived nitric oxide-cGMP-relaxant pathway, promoting prostacyclin release and/or possibly through its ability to lengthen the released nitric oxide half-life. The present data further supports previous in vivo findings and explain the traditional use of Loranthus ferrugineus as an anti-hypertensive agent.
Collapse
Affiliation(s)
- Omar Z Ameer
- Department of Physiology & Pharmacology, School of Pharmaceutical Sciences, Universiti Sains Malaysia, Minden, 11800 Penang, Malaysia.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
7
|
Sharabi FM, Daabees TT, El-Metwally MA, Senbel AM. Effect of sildenafil on the isolated rat aortic rings. Fundam Clin Pharmacol 2005; 19:449-56. [PMID: 16011732 DOI: 10.1111/j.1472-8206.2005.00345.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: 11/30/2022]
Abstract
Sildenafil, a highly selective inhibitor of PDE 5, is effective in the treatment of erectile dysfunction. Penile erection involves relaxation of smooth muscle of corpus cavernosum and its associated arterioles. The objective of this study was to investigate the effect of sildenafil on nitric oxide/cyclic guanosine monophosphate (NO/cGMP)-dependent relaxation of rat aortic rings. The contribution of sildenafil to the vasorelaxation of rat aortic rings was also investigated. Sildenafil produced significant potentiation of acetylcholine (ACh, 2 x 10(-6) m)-induced relaxation at concentration > or =1 x 10(-8) m. Addition of sildenafil (1 x 10(-7) m) to aortic rings failed to alter the effect of N(G)-nitro-L-arginine (l-NNA, 3 x 10(-5) m) or methylene blue (MB, 3 x 10(-5) m) on ACh response. Similarly, sildenafil (1 x 10(-7) m) augmented significantly the vasorelaxation induced by sodium nitroprusside over the range of 1 x 10(-9)-1 x 10(-8) m. When added to phenylephrine (3 x 10(-6) m)-precontracted rat aortic rings, sildenafil (1 x 10(-9)-1 x 10(-4) m) induced concentration-dependent relaxation reaching a maximum of 96.48 +/- 1.44%. These relaxations were not significantly attenuated by previous incubation with L-NNA (3 x 10(-5) m) or MB (3 x 10(-5) m). Denudation did not significantly affect the vasorelaxant effect of sildenafil. Sildenafil may act in the rat aortic rings through the amplification of NO/cGMP pathway. It may augment both basal endothelial NO function and exogenous NO-dependent vasodilatation. However, sildenafil may act by a mechanism independent of NO/cGMP pathway and this mechanism contributes to its smooth muscle relaxant effect.
Collapse
Affiliation(s)
- F M Sharabi
- Department of Pharmacology, Faculty of Pharmacy, University of Alexandria, El-Khartoom Square, Alexandria, Egypt.
| | | | | | | |
Collapse
|
8
|
Abdelrahman AM, Syyong H, Tjahjadi A, Pang CCY. Possible Mechanism of the Vasodepressor Effect of Endokinin A/B in Anesthetized Rats. J Cardiovasc Pharmacol 2005; 46:269-73. [PMID: 16116330 DOI: 10.1097/01.fjc.0000175236.41573.2a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
We investigated the mechanism of the vasodepressor effect of endokinin A/B. An intravenous (IV) bolus of endokinin A/B (0.05-0.3 nmol/kg) dose-dependently decreased mean arterial pressure in thiobutabarbital-anesthetized rats. The magnitude of the response was unaffected by IV pretreatment with NG-nitro-L-arginine methyl ester (L-NAME, inhibitor of nitric oxide synthase), methylene blue (inhibitor of soluble guanylyl cyclase), indomethacin (cyclooxygenase inhibitor), or tetraethylammonium (TEA, nonspecific K+ channel blocker). L-NAME reduced the half-recovery time of the vasodepressor effect of endokinin A/B relative to responses in rats pretreated with either saline or norepinephrine, which caused a similar pressor effect as did L-NAME. Methylene blue, but not TEA or indomethacin, reduced the recovery time of the vasodepressor effect of endokinin A/B. Therefore, the vasodepressor effect of endokinin A/B is mediated via the nitric oxide/L-arginine pathway and activation of soluble guanylyl cyclase but not by production of prostanoids or opening of TEA-sensitive K+ channels.
Collapse
Affiliation(s)
- Aly Mohamed Abdelrahman
- Department of Pharmacology, College of Medicine and Health Sciences, Sultan Qaboos University, Sultanate of Oman
| | | | | | | |
Collapse
|
9
|
Abdelrahman AM, Syyong HTT, Tjahjadi AAG, Pang CCY. Analysis of the mechanism of the vasodepressor effect of urocortin in anesthetized rats. Pharmacology 2004; 73:175-9. [PMID: 15604589 DOI: 10.1159/000082749] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2004] [Accepted: 10/01/2004] [Indexed: 11/19/2022]
Abstract
The aim was to examine if the depressor effect of urocortin involves activation of the nitric oxide (NO)/L-arginine pathway, production of prostanoids or opening of K(+)-channels. I. v. bolus urocortin (0.1-3 nmol/kg) dose-dependently decreased mean arterial pressure in thiobutabarbital-anesthetized rats. The depressor effect of urocortin was unaffected by pretreatment with N(G)-nitro-L-arginine methyl ester (L-NAME, inhibitor of NO synthase, i.v. bolus) or noradrenaline (i.v. infusion), which increased arterial pressure to a similar level as that produced by L-NAME. In addition, methylene blue (inhibitor of soluble guanylyl cyclase, i.v. infusion), indomethacin (cyclooxygenase inhibitor, i.v. bolus), glibenclamide (blocker of ATP-sensitive K(+)-channels, i.v. bolus) or tetraethylammonium (a non specific K(+)-channel blocker, i.v. bolus) did not affect the depressor effect of urocortin. In conclusion, the depressor effect of urocortin in anesthetized rats is not mediated via the NO/L-arginine pathway, activation of soluble guanylyl cyclase, production of prostanoids, opening of TEA sensitive K(+)-channels nor opening of ATP sensitive K(+)-channels.
Collapse
Affiliation(s)
- Aly M Abdelrahman
- Department of Pharmacology and Therapeutics, Faculty of Medicine, The University of British Columbia, 2176 Health Sciences Mall, Vancouver, BC, V6T 1Z3, Canada
| | | | | | | |
Collapse
|
10
|
Guerrero MF, Puebla P, Carrón R, Martín ML, San Román L. Quercetin 3,7-dimethyl ether: a vasorelaxant flavonoid isolated from Croton schiedeanus Schlecht. J Pharm Pharmacol 2002; 54:1373-8. [PMID: 12396299 DOI: 10.1211/002235702760345455] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
The vasorelaxant profile of quercetin 3,7-dimethyl ether, a flavonoid isolated from Croton schiedeanus Schlecht (Euphorbiaceae), was assessed in aortic rings isolated from Wistar rats. To gain insight into its structure-activity relationship, we compared this substance with quercetin 3,4',7-trimethyl ether (ayanin), another flavonoid isolated from this plant, quercetin 3,3',4',7-tetramethyl ether, a flavonoid synthesized by us, and quercetin. In addition we examined the interaction of quercetin 3,7-dimethyl ether with the nitric oxide (NO)/cyclic guanosine monophosphate (cGMP) pathway. According to their pEC50 values (concentration producing a 50% inhibition of the maximal contractile response) to phenylephrine-induced precontraction in rat isolated aorta, the potency order was quercetin 3,7-dimethyl ether > quercetin > quercetin 3,4',7-trimethyl ether > quercetin 3,3',4',7-tetramethyl ether (4.70+/-0.18; 3.96+/-0.07; 3.64+/-0.02; 3.11+/-0.16). The relaxant effect of quercetin 3,7-dimethyl ether was significantly decreased by the removal of endothelium as well as by methylene blue, an inhibitor of guanylyl cyclase, and by N(G)-nitro-L-arginine methyl ester hydrochloride (L-NAME), an NO-synthase inhibitor. Therefore, quercetin 3,7-dimethyl ether has a NO/cGMP pathway-related profile, with increased vasorelaxant activity due to hydroxylation at positions 3 and 4 of the B ring. In addition, methylation at positions 3 and 7 with respect to quercetin of the C and A rings, respectively, seems to further enhance the vasorelaxant activity of quercetin 3,7-dimethyl ether.
Collapse
Affiliation(s)
- M F Guerrero
- Laboratorio de Farmacognosia y Farmacología, Facultad de Farmacia, Universidad de Salamanca, E-37007 Salamanca, Spain
| | | | | | | | | |
Collapse
|
11
|
Pérez-Vizcaíno F, Cogolludo AL, Zaragozá-Arnáez F, Fajardo S, Ibarra M, López-López JG, Tamargo J. Vasodilator effects of sodium nitroprusside, levcromakalim and their combination in isolated rat aorta. Br J Pharmacol 1999; 128:1419-26. [PMID: 10602320 PMCID: PMC1571775 DOI: 10.1038/sj.bjp.0702924] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
1. The endothelial modulation of the relaxant responses to the nitric oxide (NO) donor sodium nitroprusside (SNP) and the KATP channel opener levcromakalim (LEM) and the interactions between these agents were analysed in isolated rat aorta. 2. LEM-induced relaxation was unchanged by endothelium removal or by the presence of L-NAME (10-4 M) or ODQ (10-6 M). In contrast, in KCl- (25 mM), but not in noradrenaline- (NA, 10-6 M) contracted arteries, SNP-induced relaxation was augmented by endothelium removal but not by L-NAME, indomethacin, glibenclamide nor charybdotoxin plus apamin. 3. The isobolographic analysis of the interactions between exogenously activated KATP channels and cyclic GMP using mixtures of SNP and LEM revealed that there were no interactions between both drugs at the proportions at which both drugs were active. However, the points for the SNP : LEM mixtures in proportions 10:1 and 1:10,000 (i.e. at concentrations at which LEM and SNP were inactive, respectively) fell significantly above the line of additivity indicating that there were negative interactions between both drugs at these selected proportions (about 5- and 2 fold inhibition, respectively). The former interaction was sensitive to glibenclamide, whereas the latter was insensitive ODQ. The magnitude of the 10:1 SNP:LEM interaction was smaller in endothelium-intact arteries and was absent in arteries stimulated by NA. 4. In conclusion, the relaxations induced by LEM and SNP were additive. However, the presence of endothelium and low concentrations of LEM inhibited SNP-induced relaxation. Both inhibitory effects were not additive and were only observed in KCl- and not in NA-contracted aortae.
Collapse
MESH Headings
- Adenosine Triphosphate/physiology
- Animals
- Aorta, Thoracic/drug effects
- Aorta, Thoracic/metabolism
- Aorta, Thoracic/physiology
- Cromakalim/pharmacology
- Cyclic GMP/antagonists & inhibitors
- Cyclic GMP/biosynthesis
- Cyclic GMP/physiology
- Drug Combinations
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/metabolism
- Endothelium, Vascular/physiology
- In Vitro Techniques
- Male
- Muscle Relaxation/drug effects
- Muscle Relaxation/physiology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/physiology
- Nitric Oxide/antagonists & inhibitors
- Nitric Oxide/physiology
- Nitric Oxide Donors/pharmacology
- Nitroprusside/pharmacology
- Potassium Channels/drug effects
- Potassium Channels/physiology
- Rats
- Rats, Wistar
- Vasodilator Agents/pharmacology
Collapse
Affiliation(s)
- F Pérez-Vizcaíno
- Departamento de Farmacología, Instituto de Farmacología y Toxicología (CSIC), Facultad de Medicina, Universidad Complutense de Madrid, 28040 Madrid, Spain.
| | | | | | | | | | | | | |
Collapse
|
12
|
May JW, Silverman RP, Kaufman JA. Flap perfusion mapping: TRAM flap after abdominal suction-assisted lipectomy. Plast Reconstr Surg 1999; 104:2278-81. [PMID: 11149798 DOI: 10.1097/00006534-199912000-00055] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
This technique or its modification (using other dyes) may play a beneficial role in other clinical scenarios where the reconstructive plastic surgeon preoperatively needs to know the integrity of vessels that are too small to image using standard angiographic techniques. In addition, flap perfusion mapping can demonstrate the pattern of skin that is physiologically perfused by the intact vessels. Knowledge of the perfusion characteristics of the tissues to be transferred before surgery may, at the least, alter the design of the tissues to be transferred and, in the extreme case, could affect the nature of the operative choice altogether.
Collapse
Affiliation(s)
- J W May
- Division of Plastic Surgery, the Massachusetts General Hospital, Boston 02114, USA
| | | | | |
Collapse
|
13
|
Zhao H, Shimokawa H, Uragami-Harasawa L, Igarashi H, Takeshita A. Long-term vascular effects of Nomega-nitro-L-arginine methyl ester are not soley mediated by inhibition of endothelial nitric oxide synthesis in the rat mesenteric artery. J Cardiovasc Pharmacol 1999; 33:554-66. [PMID: 10218725 DOI: 10.1097/00005344-199904000-00007] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Nomega-nitro-L-arginine methyl ester (L-NAME), one of the synthetic L-arginine analogues with inhibitory effects of nitric oxide (NO) synthesis, is now widely used to examine the role of NO in various organs. We and others demonstrated that long-term treatment with L-NAME causes hypertension and cardiovascular lesions (perivascular fibrosis and medial thickening), especially at microvascular levels. However, convincing evidence is still lacking that these long-term cardiovascular effects of L-NAME are solely mediated by the inhibition of the synthesis of endothelium-derived NO (EDNO). This study was thus designed to better understand the effects of long-term treatment with L-NAME with special reference to EDNO synthesis. Male Wister-Kyoto rats were orally administered L-NAME for 8 weeks. Blood pressure significantly increased at 3 days and 1 and 8 weeks of the treatment. Endothelium-dependent relaxations to acetylcholine (ACh) of the aorta were reduced 3 days after the treatment, recovered at 1 week, and again reduced at 8 weeks, whereas the relaxations of the small mesenteric artery were unaltered throughout the experimental periods. At 8 weeks, indomethacin-sensitive, endothelium-dependent contractions to ACh were noted. The relative contributions of NO and endothelium-derived hyperpolarizing factor also were unchanged. Citrulline assay demonstrated that substantial levels of constitutive NO synthase activity remained in the aorta during the experiments. The long-term treatment with L-NAME caused perivascular fibrosis and medial thickening, not only in the aorta but also in the mesenteric artery. These results suggest that mechanism(s) other than simple inhibition of EDNO synthesis is involved in the long-term cardiovascular effects of L-NAME in the rat mesenteric artery.
Collapse
Affiliation(s)
- H Zhao
- Research Institute of Angiocardiology and Cardiovascular Clinic, Kyushu University School of Medicine, Fukuoka, Japan
| | | | | | | | | |
Collapse
|
14
|
Fukami Y, Toki Y, Numaguchi Y, Nakashima Y, Mukawa H, Matsui H, Okumura K, Ito T. Nitroglycerin-induced aortic relaxation mediated by calcium-activated potassium channel is markedly diminished in hypertensive rats. Life Sci 1998; 63:1047-55. [PMID: 9749827 DOI: 10.1016/s0024-3205(98)00366-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Nitroglycerin (NTG), a nitric oxide (NO) donor, is considered to relax vascular smooth muscle by stimulating soluble guanylate cyclase, which in turn increases cyclic GMP (cGMP) level. Recently it became evident that NO-induced vasodilatation is also mediated by stimulating Ca-activated K (K(Ca)) channels directly and/or indirectly through cGMP. We, therefore, tried to investigate the possible involvement or the alteration of K(Ca) channels in the mechanism of vasodilation induced by NTG in physiological and pathological conditions. Using rings prepared from thoracic aortas of spontaneously hypertensive rats (SHR) and those of age-matched Wistar-Kyoto rats (WKY), we studied changes in isometric tension of the rings in response to NTG to evaluate effects of a soluble guanylate cyclase inhibitor methylene blue (MB), and a specific blocker of K(Ca) channel charybdotoxin (CTX). Rings from WKY and SHR precontracted with norepinephrine showed similar aortic relaxation to NTG. MB markedly suppressed the NTG-induced relaxation in both strains, leaving about 30% of MB-resistant relaxation. CTX nearly completely eliminated this MB-resistant relaxation in WHY but did not affect this relaxation in SHR. These results suggest that NTG-induced vasorelaxation is mediated through i) cGMP-dependent and ii) cGM P-independent K(Ca) channel involving mechanisms, the latter may be diminished or virtually eliminated in hypertensive state.
Collapse
Affiliation(s)
- Y Fukami
- Internal Medicine II, Nagoya University School of Medicine, Japan
| | | | | | | | | | | | | | | |
Collapse
|
15
|
Rosselet A, Feihl F, Markert M, Gnaegi A, Perret C, Liaudet L. Selective iNOS inhibition is superior to norepinephrine in the treatment of rat endotoxic shock. Am J Respir Crit Care Med 1998; 157:162-70. [PMID: 9445295 DOI: 10.1164/ajrccm.157.1.9701017] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
S-methyl-isothiourea (SMT) is a potent inhibitor of NO synthase (NOS) with relative selectivity towards the inducible isoform (iNOS). We compared SMT and norepinephrine for the treatment of experimental endotoxic shock. Anesthetized rats challenged intravenously with lipopolysaccharide (LPS), 10 mg/kg, were treated after 1 h with a 4-h infusion of norepinephrine (titrated to maintain blood pressure within baseline values), SMT at low dose (0.1 mg x kg-1 x h-1), or at high dose (1 mg x kg-1 x h-1), or an equivalent volume of saline (2 ml x kg-1 x h-1). In saline-treated animals, LPS increased plasma nitrate and produced hypotension, low cardiac output (CO), lactic acidosis, and signs of liver and kidney dysfunction. Norepinephrine maintained blood pressure (BP) and reduced the fall in CO, without affecting lactic acidosis, organ dysfunction, and nitrate accumulation. The latter was dose-dependently blunted by SMT. Treatment with this agent prevented hypotension, through systemic vasoconstriction with the high dose and a maintained CO with the low dose. Low, but not high, dose SMT blunted lactic acidosis. Both doses reduced the signs of renal, but not liver, dysfunction. In additional studies, we obtained evidence that, in contrast with the high dose, SMT at low dose did not interfere with the function of constitutive NOS. These findings suggest a potential advantage of selective iNOS inhibition over standard adrenergic support in the therapy of septic shock.
Collapse
Affiliation(s)
- A Rosselet
- Institute of Pathophysiology and Central Laboratory for Clinical Chemistry, University Hospital, Lausanne, Switzerland
| | | | | | | | | | | |
Collapse
|
16
|
Koyama K, Kasuya Y, Koyama K, Goto K. Nitric oxide-mediated vasorelaxation induced by sodium polyoxyethylene laurylether sulfate. Toxicol Appl Pharmacol 1997; 145:294-300. [PMID: 9266802 DOI: 10.1006/taap.1997.8192] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Ingestion of surfactants is known to cause hemodynamic changes with decreased total vascular resistance. Motivated by this clinical observation, we investigated the direct effects of a common anionic surfactant, sodium polyoxyethylene laurylether sulfate (LES), on isolated ring segments of rat thoracic aorta. LES did not produce any vasocontractile responses, but relaxed ring segments precontracted with 10(-6) M phenylephrine in a concentration-dependent manner. This LES-induced vasorelaxation was significantly reduced by the removal of endothelium or pretreatment with N(G)-nitro-L-arginine methylester hydrochloride, methylene blue, or oxyhemoglobin to the same degree, but was not affected by pretreatment with indomethacin. A further study measuring NO2- plus NO3- (NO(x), total metabolites of NO) in the medium of calf pulmonary artery endothelial (CPAE) cells, a cultured cell line, revealed that LES caused a significant increase in NO(x) production. On the other hand, in a study measuring intracellular Ca2+ in fura-2-loaded CPAE cells, LES caused a significant increase in intracellular Ca2+. These results suggest that LES causes endothelium-dependent vasorelaxation via a NO-mediated signaling pathway, which might be due to Ca2+ mobilization.
Collapse
Affiliation(s)
- K Koyama
- Department of Emergency Medicine, Institute of Clinical Medicine, University of Tsukuba, Ibaraki, Japan
| | | | | | | |
Collapse
|
17
|
Prostran MS, Todorović Z, Varagić VM. Physostigmine and modulators of nitric oxide system on the mean arterial pressure of the spontaneously hypertensive rat. GENERAL PHARMACOLOGY 1997; 28:105-12. [PMID: 9112085 DOI: 10.1016/s0306-3623(96)00158-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
1. A slow intravenous infusion of L-arginine (3 mg kg-1) lasting one hr produced significant hypotension in urethane-anaesthetized spontaneously hypertensive rats (SHRs). 2. A slow intravenous infusion of NG-nitro-L-arginine methyl ester (L-NAME) (3 mg kg-1 h-1) did not produce any significant change in the mean arterial pressure during infusion. After stopping infusion of L-NAME, a slowly developing increase of the mean arterial pressure was observed during the following 40 min. 3. The pressor response to physostigmine (20, 40 and 80 micrograms kg-1, IV), injected during a slow intravenous infusion of either L-arginine or L-NAME, was not changed. 4. L-arginine and L-NAME depressed the pressor responses to physostigmine, if physostigmine was injected after the end of a 1-hr infusion. 5. Acute pretreatment with increasing doses of physostigmine markedly affected the blood pressure response to L-arginine (i.e., L-arginine-caused hypotension was more pronounced), but only slightly that to L-NAME. 6. In conclusion, L-arginine, as a donor of NO, produced hypotension by itself and also decreased, but not significantly, the central cholinergically-mediated hypertension (CCMH) produced by physostigmine. It is quite possible that the peripheral NO released by L-arginine antagonized the increased adrenergic activity in the CCMH. This does happen in normotensive rats, but to a lesser degree than in SHRs, as shown in the current experiments. 7. Also, our results show that inhibition of endogenous NO biosynthesis using L-NAME does not necessarily lead to pressor response in vivo, at least in SHRs. It is concluded that L-arginine-nitric oxide pathways operate in SHRs, as well as in normotensive Wistar rats, but their role in modulating cholinergically-mediated regulation of the mean arterial pressure is less pronounced in SHRs than in normotensive animals.
Collapse
Affiliation(s)
- M S Prostran
- Department of Pharmacology, Faculty of Medicine, Belgrade, Yugoslavia
| | | | | |
Collapse
|
18
|
|
19
|
Methylene Blue Infusion in Septic Shock. Crit Care Med 1995. [DOI: 10.1097/00003246-199511000-00032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|