title: Effect of the venom of the snake Cerastes cerastes (African desert horned viper) on the response of the rat vas deferens to field stimulation.
abstract: Cerastes cerastes venom in low concentrations (0.8-2.5 micrograms/ml) inhibited the response of the rat vas deferens to field stimulation, while higher concentrations (4-8 micrograms/ml) causes a contracture that was reversed by washing and transiently blocked by phentolamine. The effect of the venom and guanethidine (10(-7) M) was reversed by tyramine (4.6 x 10(-8) M) but unaffected by hexamethonium (1.4 x 10(-7) M). When the response to field stimulation was inhibited by the venom the response to norepinephrine was either potentiated or unchanged.
mesh_terms: D000818:Animals; D004558:Electric Stimulation; D006145:Guanethidine / Q000494:pharmacology; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D010646:Phentolamine / Q000494:pharmacology; D051381:Rats; D012911:Snakes; D009435:Synaptic Transmission / Q000187:drug effects*; D014439:Tyramine / Q000494:pharmacology; D014649:Vas Deferens / Q000187:drug effects*; D014757:Viper Venoms / Q000633:toxicity*
chemical_list: D014757:Viper Venoms; D014439:Tyramine; D010646:Phentolamine; D006145:Guanethidine