Excitatory and inhibitory effects of a myotoxin from Conus magus venom on the mouse diaphragm, the guinea-pig atria, taenia caeci, ileum and vas deferens.
A myotoxin purified from Conus magus venom elicited complete loss of contractile response of the mouse diaphragm to electrical stimulation followed by a gradual rise in the baseline, an increase in the contractile force of the guinea-pig left atria, a tonic contraction of the guniea-pig taenia caeci and powerful rhythmic contractions of the guinea-pig ileum and vas deferens. These excitatory effects of the toxin were blocked by treatment with tetrodotoxin, suggesting that these effects were due to an increase in Na+ permeability of the cell membrane.
D000818:Animals; D002432:Cecum / Q000187:drug effects; D003964:Diaphragm / Q000187:drug effects; D004558:Electric Stimulation; D006168:Guinea Pigs; D007082:Ileum / Q000187:drug effects; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D008978:Mollusk Venoms / Q000494:pharmacology*; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects*; D009200:Myocardial Contraction / Q000187:drug effects*; D014118:Toxins, Biological / Q000494:pharmacology*; D014649:Vas Deferens / Q000187:drug effects
D008978:Mollusk Venoms; D014118:Toxins, Biological