An analysis of the characteristics of the adrenergic neurone blocking action of dimethylphenylpiperazinium.
An analysis of the characteristics of the adrenergic neurone blocking action of 1,1-dimethyl-4-phenylpiperazinium (DMPP) was undertaken using rat isolated vasa deferentia. DMPP (1 X 10(-6) to 1.5 X 10(-5) g/ml) reduced progressively the contractile response to transmural stimulation (TMS) in a dose-dependent manner without inhibiting the response to exogenous norepinephrine. The DMPP-induced inhibition was not reversed by washing but could be antagonized by dexamphetamine in a concentration which did not by itself affect the response to TMS. Among other sympathomimetic amines tested, it was seen that methamphetamine, ephedrine, phenylpropranolamine and mephentermine were effective in antagonizing DMPP-induce inhibition. High calcium (5 mM) reversed but did not prevent the DMPP-induced inhibition. DMPP reduced preferentially responses to high frequencies of stimulation without affecting those to low.
D000818:Animals; D002118:Calcium / Q000494:pharmacology; D003864:Depression, Chemical; D003913:Dextroamphetamine / Q000494:pharmacology; D004246:Dimethylphenylpiperazinium Iodide / Q000494:pharmacology*; D004347:Drug Interactions; D004558:Electric Stimulation; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects; D009474:Neurons / Q000187:drug effects*; D010879:Piperazines / Q000494:pharmacology*; D051381:Rats; D013564:Sympathetic Nervous System / Q000166:cytology / Q000187:drug effects*; D013566:Sympathomimetics / Q000494:pharmacology; D014649:Vas Deferens / Q000187:drug effects
D010879:Piperazines; D013566:Sympathomimetics; D004246:Dimethylphenylpiperazinium Iodide; D002118:Calcium; D003913:Dextroamphetamine