Characterization of muscarinic receptor subtype mediating contraction and relaxation in equine coronary artery in vitro.
Abstract: In coronary arterial rings isolated from horses, 10(-8)-10(-6) mol/l acetylcholine (ACh) induced concentration-dependent contractions which were potentiated by the removal of endothelium and by pretreatment with L-nitro-arginine (LNAG) or methylene blue (MB). Relatively lower concentrations of ACh (10(-14)-10(-8) mol/l) induced relaxation when the coronary rings were contracted by phenylephrine (PE). ACh-induced contractions in the coronary rings without endothelium were competitively inhibited by each muscarinic subtype selective antagonist in the following order of potency: 4-diphenylacetoxy-N-methylpiperidine methiodide (4-DAMP) > pirenzepine > or = parafluoro-hexahydrosiladiphenidol (pFHHSiD) > methoctramine. ACh-induced relaxation in the rings with endothelium was inhibited by LNAG or MB, and by each selective antagonist in the following order of potency: 4-DAMP > pFHHSiD > pirenzepine > methoctramine. These results suggest that the ACh-induced contraction and relaxation in equine coronary arteries are mediated mainly by an M3-receptor located on the smooth muscle cells and endothelial cells, respectively, and that the stimulation of the M3-receptor on the endothelial cells liberates nitric oxide.
Publication Date: 1994-06-01 PubMed ID: 7933061DOI: 10.1111/j.1365-2885.1994.tb00237.xGoogle Scholar: Lookup
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- Journal Article
Summary
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The article discusses a study on how acetylcholine, a chemical that transmits nerve impulses, influences muscle contraction and relaxation in horse coronary arteries. This influence appears to be mostly mediated through a specific subtype of receptor called the M3-receptor.
Background and Experimental Setup
- The research focuses on the characterization of the muscarinic receptor subtype, specifically the M3-receptor, in the equine coronary artery. This involves studying how these receptors mediate contraction and relaxation.
- For this experiment, coronary arterial rings were isolated from horses. These samples were subjected to varying concentrations of acetylcholine (ACh), a neurotransmitter crucial for muscle movement and function.
Observations and Findings
- The presence of 10(-8)-10(-6) mol/l acetylcholine resulted in concentration-dependent contractions. Moreover, the removal of the endothelium, the innermost lining of the blood vessels, and pretreatment with L-nitro-arginine (LNAG) or methylene blue intensified these contractions.
- Interestingly, lower concentrations of acetylcholine led to relaxation when the coronary rings were already contracted by the action of another compound named phenylephrine.
- When the endothelium was removed, contractions induced by acetylcholine could be competitively inhibited by each muscarinic subtype selective antagonist. These compounds block the interaction of acetylcholine with its receptor and were effective in the following order: 4-DAMP > pirenzepine > or = parafluoro-hexahydrosiladiphenidol > methoctramine.
Conclusions and Implications
- The contractions and relaxations induced by acetylcholine in the equine coronary arteries were found to be mainly mediated by an M3-receptor. This receptor is present in both the smooth muscle cells and the endothelial cells.
- The stimulation of the M3-receptor in the endothelial cells releases nitric oxide, a gas that plays an important role in vascular relaxation.
Cite This Article
APA
Obi T, Kabeyama A, Nishio A.
(1994).
Characterization of muscarinic receptor subtype mediating contraction and relaxation in equine coronary artery in vitro.
J Vet Pharmacol Ther, 17(3), 226-231.
https://doi.org/10.1111/j.1365-2885.1994.tb00237.x Publication
Researcher Affiliations
- Department of Veterinary Pharmacology, Faculty of Agriculture, Kagoshima University, Japan.
MeSH Terms
- Acetylcholine / pharmacology
- Animals
- Arginine / analogs & derivatives
- Arginine / pharmacology
- Arteries
- Coronary Vessels / drug effects
- Coronary Vessels / physiology
- Electrophysiology
- Endothelium, Vascular / physiology
- Horses
- In Vitro Techniques
- Methylene Blue
- Muscarinic Antagonists / pharmacology
- Muscle, Smooth, Vascular / physiology
- Nitroarginine
- Receptors, Muscarinic / classification
- Receptors, Muscarinic / physiology
- Vasoconstriction / drug effects
- Vasoconstriction / physiology
- Vasodilation / drug effects
- Vasodilation / physiology
Citations
This article has been cited 5 times.- de Lacerda Neto LJ, Ramos AGB, da Silva RER, Pereira-de-Morais L, Silva FM, da Costa RHS, Rodrigues Dantas LB, da Costa JGM, Coutinho HDM, Kowalska G, Hawlena J, Kowalski R, Barbosa R, da Cunha FAB. Myorelaxant Effect of the Dysphania ambrosioides Essential Oil on Sus scrofa domesticus Coronary Artery and Its Toxicity in the Drosophila melanogaster Model.. Molecules 2021 Apr 2;26(7).
- Chen X, Walther FJ, van Boxtel R, Laghmani EH, Sengers RM, Folkerts G, DeRuiter MC, Cuppen E, Wagenaar GT. Deficiency or inhibition of lysophosphatidic acid receptor 1 protects against hyperoxia-induced lung injury in neonatal rats.. Acta Physiol (Oxf) 2016 Mar;216(3):358-75.
- Wagenaar GT, Sengers RM, Laghmani el H, Chen X, Lindeboom MP, Roks AJ, Folkerts G, Walther FJ. Angiotensin II type 2 receptor ligand PD123319 attenuates hyperoxia-induced lung and heart injury at a low dose in newborn rats.. Am J Physiol Lung Cell Mol Physiol 2014 Aug 1;307(3):L261-72.
- Gericke A, Steege A, Manicam C, Böhmer T, Wess J, Pfeiffer N. Role of the M3 muscarinic acetylcholine receptor subtype in murine ophthalmic arteries after endothelial removal.. Invest Ophthalmol Vis Sci 2014 Jan 29;55(1):625-31.
- Gericke A, Sniatecki JJ, Mayer VG, Goloborodko E, Patzak A, Wess J, Pfeiffer N. Role of M1, M3, and M5 muscarinic acetylcholine receptors in cholinergic dilation of small arteries studied with gene-targeted mice.. Am J Physiol Heart Circ Physiol 2011 May;300(5):H1602-8.
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