title: Mechanisms of methacholine-induced coronary vasospasm in an experimental model of variant angina in the anesthetized rat.
abstract: Methacholine (Mch), when injected near the ostia of the coronary arteries, induces an intense coronary vasospasm which can be measured by the degree of S wave elevation monitored from an electrocardiogram (ECG). The observed ECG changes resemble those occurring in patients with variant angina. The effects of Mch were blocked by atropine, but not by d-tubocurarine, hexamethonium, adrenergic receptor blockade, or prior reserpinization, indicating that Mch is acting directly on muscarinic receptors to produce a vasoconstriction of the coronary arteries. This model of Mch-induced coronary vasospasm appears to be useful for testing spasmolytic agents which might be of benefit in variant angina.
mesh_terms: D000788:Angina Pectoris, Variant / Q000139:chemically induced*; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects; D003326:Coronary Circulation / Q000187:drug effects; D003329:Coronary Vasospasm / Q000139:chemically induced*; D004195:Disease Models, Animal; D006339:Heart Rate / Q000187:drug effects; D006584:Hexamethonium Compounds / Q000494:pharmacology; D008297:Male; D008688:Methacholine Compounds / Q000494:pharmacology*; D011433:Propranolol / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D012110:Reserpine / Q000494:pharmacology; D014403:Tubocurarine / Q000494:pharmacology
chemical_list: D006584:Hexamethonium Compounds; D008688:Methacholine Compounds; D001285:Atropine; D012110:Reserpine; D011433:Propranolol; D014403:Tubocurarine