Cardiotropic antimuscarinic action of some curare-like agents.
In anesthetized cats antidepolarising curare-like drugs anatruxonium, cyclobutonium, diadonium and decadonium in doses lower than myoparalytic ones, completely blocked acetylcholine-induced bradycardia, only slightly changing the hypotensive action. In a myoparalytic dose anatruxonium and cyclobutonium decreased acetylcholine bronchospasm approximately by 50 %, diadonium altered this response in various directions, while decadonium essentially increased the bronchoconstricting action of acetylcholine. Anatuxonium and cyclobutonium failed to affect significantly the ileum, urinary bladder or salivary glands responses to acetylcholine; diadonium increased or did not change these reactions, while decadonium significantly enhanced them. Anatruxonium like atropine antagonized carbachol effects on isolated ileum and spontaneously beating atria of the rat, causing parallel shifts of the concentration-response curves for the agonist with no depression of maximum responses. Still, unlike atropine the affinity (pA2) of anatruxonium for muscarine-sensitive acetylcholine receptors of the atria was higher than that for the receptors of the ileum. The data obtained testify to the heterogenity of muscarine-sensitive acetylcholine receptors of different localisation.
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002415:Cats; D005260:Female; D006321:Heart / Q000187:drug effects*; D006439:Hemodynamics / Q000187:drug effects; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D003473:Neuromuscular Nondepolarizing Agents / Q000378:metabolism / Q000494:pharmacology*; D010276:Parasympatholytics; D051381:Rats; D011976:Receptors, Muscarinic / Q000378:metabolism; D012472:Salivation / Q000187:drug effects
D003473:Neuromuscular Nondepolarizing Agents; D010276:Parasympatholytics; D011976:Receptors, Muscarinic