Enhancement by oxotremorine of acetylcholine release from the rat phrenic nerve.
Oxotremorine (10.5 micron) produced a paralytic effect on twitch responses of rat diaphragm in vitro to direct and indirect stimulation. 2 The paralytic effect of oxotremorine was absent when the diaphragm was stimulated directly in the presence of hemicholinium-3 (0.42 mM), at a time when twitch responses to indirect stimulation ceased completely. 3 Oxotremorine, at two different pharmacologically active doses, strikingly increased the resting as well as electrically evoked release of acetylcholine into the bathing fluid from the phrenic nerve-diaphragm preparation. 4 This presynaptic effect of oxotremorine may explain its pharmacological effects at the cholinergic synapses studied so far.
D000109:Acetylcholine / Q000378:metabolism*; D000818:Animals; D004558:Electric Stimulation; D005260:Female; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009121:Muscle Denervation; D009469:Neuromuscular Junction / Q000187:drug effects; D010095:Oxotremorine / Q000494:pharmacology*; D010791:Phrenic Nerve / Q000187:drug effects* / Q000378:metabolism; D051381:Rats; D013268:Stimulation, Chemical; D009435:Synaptic Transmission / Q000187:drug effects
D010095:Oxotremorine; D000109:Acetylcholine