Antioxotremorine action of propranolol.
1. The influence of propranolol on the neuromuscular, tremor-producing and muscarinic effects of oxotremorine was examined. 2. In the isolated rat phrenic nerve-diaphragm preparation the neuromuscular blocking effect of oxotremorine was inhibited by propranolol in a dose-dependent manner. 3. Propranolol intensified the paralytic effect of tubocurarine in the rat diaphragm and prevented antagonism of tubocurarine paralysis by tetraethylammonium. 4. Propranolol was devoid of any curare-like effect in the isolated rectus abdominis muscle of the frog. 5. Vasodepressor responses to oxotremorine in rats and spasmogenic responses to oxotremorine in guinea-pig ileum were not antagonized by propranolol. 6. A dose-dependent antagonism of oxotremorine-induced tremor in mice was observed after pretreatment with propranolol and it is suggested that this effect is due to an antagonism of a presynaptic effect of oxotremorine at skeletal neuromuscular junctions.
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D003964:Diaphragm / Q000187:drug effects; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D009119:Muscle Contraction / Q000187:drug effects; D010095:Oxotremorine / Q000037:antagonists & inhibitors*; D010791:Phrenic Nerve / Q000187:drug effects; D011433:Propranolol / Q000494:pharmacology*; D011817:Rabbits; D051381:Rats; D014202:Tremor / Q000139:chemically induced; D014403:Tubocurarine / Q000494:pharmacology
D010095:Oxotremorine; D011433:Propranolol; D014403:Tubocurarine