Effects of organophosphate insecticides on the cholinergic receptors of frog skeletal muscle.
The organophosphates octamethyl pyrophosphoramide, Bidrin, and phosphoric acid 2,2-dichlorovinyl dimethyl ester inhibit the membrane voltage response of frog sartorius muscles to carbamylcholine in a manner expected of either a slowly reversing competitive inhibitor or a noncompetitive inhibitor. The inhibition reverses with a time course of minutes, depending upon the temperature. The inhibition by these compounds is reduced by d-tubocurarine but is unaffected by hexamethonium. This may indicate that the organophosphate binding sites are near the cholinergic binding site since both d-tubocurarine and hexamethonium are competitive inhibitors of cholinergic agonists and d-tubocurarine is the larger compound.
D000109:Acetylcholine / Q000378:metabolism; D000110:Acetylcholinesterase / Q000378:metabolism; D000818:Animals; D001001:Anura; D002217:Carbachol / Q000494:pharmacology; D003864:Depression, Chemical; D004347:Drug Interactions; D066298:In Vitro Techniques; D007306:Insecticides / Q000494:pharmacology*; D008564:Membrane Potentials / Q000187:drug effects; D009045:Motor Endplate / Q000187:drug effects; D009121:Muscle Denervation; D009132:Muscles / Q000187:drug effects*; D009943:Organophosphorus Compounds; D011950:Receptors, Cholinergic / Q000187:drug effects*; D013997:Time Factors
D007306:Insecticides; D009943:Organophosphorus Compounds; D011950:Receptors, Cholinergic; D002217:Carbachol; D000110:Acetylcholinesterase; D000109:Acetylcholine