Abstract
1. Experiments were designed to characterize the subtype(s) of endothelial muscarinic receptor that mediate(s) endothelium-dependent relaxation and contraction in the aorta of spontaneously hypertensive rats (SHR). 2. Rings of SHR aorta with endothelium were suspended in organ baths for the measurement of isometric force. Ecothiopate (an inhibitor of acetylcholinesterase) was present throughout the experiments. Endothelium-dependent contraction to acetylcholine was studied in quiescent aortic rings in the presence of NG-nitro-L-arginine (to prevent the formation of nitric oxide). Endothelium-dependent relaxation to acetylcholine was obtained during contraction to phenylephrine and in the presence of indomethacin (to inhibit cyclo-oxygenase activity). Responses to acetylcholine were assessed against the non-preferential muscarinic receptor antagonist, atropine, and the preferential antagonists pirenzepine (M1), methoctramine (M2) and 4-diphenylacetoxy-N-methylpiperidine methobromide (4-DAMP; M3). 3. The potency of acetylcholine in inducing endothelium-dependent contraction was 6.54 +/- 0.07 (EC50). Atropine, pirenzepine, methoctramine and 4-DAMP displayed competitive antagonism towards the endothelium-dependent contraction to acetylcholine. The pA2 values for these muscarinic receptor antagonists were estimated from Arunlakshana-Schild plots to be (-log M) 9.48 +/- 0.07, 6.74 +/- 0.22, 6.30 +/- 0.20 and 9.39 +/- 0.22 respectively. The potency of acetylcholine in inducing endothelium-dependent relaxation was 7.82 +/- 0.09 (IC50). Atropine, pirenzepine and 4-DAMP displayed competitive antagonism towards the endothelium-dependent relaxation to acetylcholine but methoctramine had no effect. The pA2 values for atropine and 4-DAMP for the relaxation to acetylcholine were estimated from Arunlakshana-Schild plots to be (-log M) 9.15 +/- 0.23 and 9.63 +/- 0.28, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
Full text
PDF





Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- ARUNLAKSHANA O., SCHILD H. O. Some quantitative uses of drug antagonists. Br J Pharmacol Chemother. 1959 Mar;14(1):48–58. doi: 10.1111/j.1476-5381.1959.tb00928.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Alonso M. J., Arribas S., Marín J., Balfagón G., Salaices M. Presynaptic M2-muscarinic receptors on noradrenergic nerve endings and endothelium-derived M3 receptors in cat cerebral arteries. Brain Res. 1991 Dec 13;567(1):76–82. doi: 10.1016/0006-8993(91)91438-7. [DOI] [PubMed] [Google Scholar]
- Auch-Schwelk W., Katusic Z. S., Vanhoutte P. M. Thromboxane A2 receptor antagonists inhibit endothelium-dependent contractions. Hypertension. 1990 Jun;15(6 Pt 2):699–703. doi: 10.1161/01.hyp.15.6.699. [DOI] [PubMed] [Google Scholar]
- Auch-Schwelk W., Katusić Z. S., Vanhoutte P. M. Nitric oxide inactivates endothelium-derived contracting factor in the rat aorta. Hypertension. 1992 May;19(5):442–445. doi: 10.1161/01.hyp.19.5.442. [DOI] [PubMed] [Google Scholar]
- Bassenge E., Heusch G. Endothelial and neuro-humoral control of coronary blood flow in health and disease. Rev Physiol Biochem Pharmacol. 1990;116:77–165. doi: 10.1007/3540528806_4. [DOI] [PubMed] [Google Scholar]
- Brunner F., Kühberger E., Groschner K., Pöch G., Kukovetz W. R. Characterization of muscarinic receptors mediating endothelium-dependent relaxation of bovine coronary artery. Eur J Pharmacol. 1991 Jul 23;200(1):25–33. doi: 10.1016/0014-2999(91)90661-9. [DOI] [PubMed] [Google Scholar]
- Chen G., Suzuki H., Weston A. H. Acetylcholine releases endothelium-derived hyperpolarizing factor and EDRF from rat blood vessels. Br J Pharmacol. 1988 Dec;95(4):1165–1174. doi: 10.1111/j.1476-5381.1988.tb11752.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dauphin F., Hamel E. Muscarinic receptor subtype mediating vasodilation feline middle cerebral artery exhibits M3 pharmacology. Eur J Pharmacol. 1990 Mar 20;178(2):203–213. doi: 10.1016/0014-2999(90)90476-m. [DOI] [PubMed] [Google Scholar]
- Duckles S. P., Garcia-Villalon A. L. Characterization of vascular muscarinic receptors: rabbit ear artery and bovine coronary artery. J Pharmacol Exp Ther. 1990 May;253(2):608–613. [PubMed] [Google Scholar]
- Duckles S. P. Vascular muscarinic receptors: pharmacological characterization in the bovine coronary artery. J Pharmacol Exp Ther. 1988 Sep;246(3):929–934. [PubMed] [Google Scholar]
- Eglen R. M., Michel A. D., Whiting R. L. Characterization of the muscarinic receptor subtype mediating contractions of the guinea-pig uterus. Br J Pharmacol. 1989 Mar;96(3):497–499. doi: 10.1111/j.1476-5381.1989.tb11843.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Fuder H., Schöpf J., Unckell J., Wesner M. T., Melchiorre C., Tacke R., Mutschler E., Lambrecht G. Different muscarine receptors mediate the prejunctional inhibition of [3H]-noradrenaline release in rat or guinea-pig iris and the contraction of the rabbit iris sphincter muscle. Naunyn Schmiedebergs Arch Pharmacol. 1989 Dec;340(6):597–604. doi: 10.1007/BF00717733. [DOI] [PubMed] [Google Scholar]
- Furchgott R. F., Vanhoutte P. M. Endothelium-derived relaxing and contracting factors. FASEB J. 1989 Jul;3(9):2007–2018. [PubMed] [Google Scholar]
- Furchgott R. F., Zawadzki J. V. The obligatory role of endothelial cells in the relaxation of arterial smooth muscle by acetylcholine. Nature. 1980 Nov 27;288(5789):373–376. doi: 10.1038/288373a0. [DOI] [PubMed] [Google Scholar]
- Garcia-Villalon A. L., Krause D. N., Ehlert F. J., Duckles S. P. Heterogeneity of muscarinic receptor subtypes in cerebral blood vessels. J Pharmacol Exp Ther. 1991 Jul 1;258(1):304–310. [PubMed] [Google Scholar]
- Hynes M. R., Banner W., Jr, Yamamura H. I., Duckles S. P. Characterization of muscarinic receptors of the rabbit ear artery smooth muscle and endothelium. J Pharmacol Exp Ther. 1986 Jul;238(1):100–105. [PubMed] [Google Scholar]
- Ito T., Kato T., Iwama Y., Muramatsu M., Shimizu K., Asano H., Okumura K., Hashimoto H., Satake T. Prostaglandin H2 as an endothelium-derived contracting factor and its interaction with endothelium-derived nitric oxide. J Hypertens. 1991 Aug;9(8):729–736. doi: 10.1097/00004872-199108000-00006. [DOI] [PubMed] [Google Scholar]
- Jaiswal N., Lambrecht G., Mutschler E., Tacke R., Malik K. U. Pharmacological characterization of the vascular muscarinic receptors mediating relaxation and contraction in rabbit aorta. J Pharmacol Exp Ther. 1991 Sep;258(3):842–850. [PubMed] [Google Scholar]
- Komori K., Suzuki H. Heterogeneous distribution of muscarinic receptors in the rabbit saphenous artery. Br J Pharmacol. 1987 Nov;92(3):657–664. doi: 10.1111/j.1476-5381.1987.tb11369.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lüscher T. F., Vanhoutte P. M. Endothelium-dependent contractions to acetylcholine in the aorta of the spontaneously hypertensive rat. Hypertension. 1986 Apr;8(4):344–348. doi: 10.1161/01.hyp.8.4.344. [DOI] [PubMed] [Google Scholar]
- McCormack D. G., Mak J. C., Minette P., Barnes P. J. Muscarinic receptor subtypes mediating vasodilation in the pulmonary artery. Eur J Pharmacol. 1988 Dec 13;158(3):293–297. doi: 10.1016/0014-2999(88)90083-0. [DOI] [PubMed] [Google Scholar]
- Mei L., Roeske W. R., Yamamura H. I. Molecular pharmacology of muscarinic receptor heterogeneity. Life Sci. 1989;45(20):1831–1851. doi: 10.1016/0024-3205(89)90537-7. [DOI] [PubMed] [Google Scholar]
- Michel A. D., Stefanich E., Whiting R. L. Direct labeling of rat M3-muscarinic receptors by [3H]4DAMP. Eur J Pharmacol. 1989 Aug 3;166(3):459–466. doi: 10.1016/0014-2999(89)90359-2. [DOI] [PubMed] [Google Scholar]
- Michel A. D., Whiting R. L. Methoctramine, a polymethylene tetraamine, differentiates three subtypes of muscarinic receptor in direct binding studies. Eur J Pharmacol. 1988 Jan 5;145(1):61–66. doi: 10.1016/0014-2999(88)90349-4. [DOI] [PubMed] [Google Scholar]
- Moncada S., Palmer R. M., Higgs E. A. Nitric oxide: physiology, pathophysiology, and pharmacology. Pharmacol Rev. 1991 Jun;43(2):109–142. [PubMed] [Google Scholar]
- Orphanos S. E., Catravas J. D. Muscarinic receptor subtype (M1) identification on rabbit pulmonary vascular endothelium in vivo. Pharmacology. 1989;39(4):253–264. doi: 10.1159/000138605. [DOI] [PubMed] [Google Scholar]
- Rubanyi G. M., McKinney M., Vanhoutte P. M. Biphasic release of endothelium-derived relaxing factor(s) by acetylcholine from perfused canine femoral arteries. Characterization of muscarinic receptors. J Pharmacol Exp Ther. 1987 Mar;240(3):802–808. [PubMed] [Google Scholar]
- Schini V. B., Vanhoutte P. M. Inhibitors of calmodulin impair the constitutive but not the inducible nitric oxide synthase activity in the rat aorta. J Pharmacol Exp Ther. 1992 May;261(2):553–559. [PubMed] [Google Scholar]
- Yanagisawa M., Masaki T. Endothelin, a novel endothelium-derived peptide. Pharmacological activities, regulation and possible roles in cardiovascular control. Biochem Pharmacol. 1989 Jun 15;38(12):1877–1883. doi: 10.1016/0006-2952(89)90484-x. [DOI] [PubMed] [Google Scholar]
- van Charldorp K. J., van Zwieten P. A. Comparison of the muscarinic receptors in the coronary artery, cerebral artery and atrium of the pig. Naunyn Schmiedebergs Arch Pharmacol. 1989 Apr;339(4):403–408. doi: 10.1007/BF00736054. [DOI] [PubMed] [Google Scholar]
