title: An investigation of the actions of the calcium entry facilitator Bay K 8644 on the rat vas deferens.
abstract: The pre- and postsynaptic actions of the calcium entry facilitator Bay K 8644 were investigated in the rat isolated vas deferens. Bay K 8644 had no presynaptic effect on adrenergic neurotransmission in the epididymal portion. Bay K 8644 and alpha 1-adrenoceptor agonists potentiated, and the calcium entry blocker nifedipine abolished, the non-adrenergic contraction to a single stimulus in prostatic portions. Bay K 8644 sensitised the prostatic portion to, but did not increase the maximum height of, spontaneous direct contractions produced by alpha-agonists.
mesh_terms: D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester; D000316:Adrenergic alpha-Agonists / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation; D066298:In Vitro Techniques; D007473:Ion Channels / Q000187:drug effects*; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009543:Nifedipine / Q000031:analogs & derivatives* / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D014649:Vas Deferens / Q000187:drug effects* / Q000502:physiology
chemical_list: D000316:Adrenergic alpha-Agonists; D007473:Ion Channels; D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester; D009543:Nifedipine; D002118:Calcium