Pharmacological studies on supersensitization. XI. Inhibitory effect of dibenamine on tripelennamine-N,N-dimethyl-N',N'-dibenzylethylenediamine- and N,N-dibenzyl-N', N'-dimethyl-1, 2-propanediamine-induced supersensitivity of isolated vas deferens of guinea pig.
Effects of dibenamine on tripelennamine-, N,N-dimethyl-N',N'-dibenzylethylenediamine (DBED)- and N,N-dibenzyl-N',N'-dimethyl-1,2-propanediamine (DBPD)-induced supersensitivity of isolated vas deferens of guinea pig were examined. Dibenamine attenuated the degree of tripelennamine- and DBED-induced increase in sensitivity to acetylcholine and potassium in standard Tyrode solution, but did not affect the degree of DBPD-induced increase in sensitivity to acetylcholine. Dibenamine diminished the degree of tripelennamine-induced increase, but did not affect the degree of DBED-induced increase, in maximum response to Ca2+ of partially depolarized vas deferens. Dibenamine diminished the degree of tripelennamine- and DBED-induced augmentation of potassium-contraction in Ca2+-free Tyrode solution, but did not affect that of acetylcholine-contraction. These results suggest that dibenamine prevent tripelennamine- and DBED-induced increase in Ca2+-influx (including extracellular Ca2+-superficial Ca2+ exchange) induced by acetylcholine and potassium. It is also suggested that DBPD potentiates acetylcholine-contraction by dibenamine-insensitive mechanisms.
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000494:pharmacology; D003959:Diamines / Q000494:pharmacology*; D003983:Dibenzylchlorethamine / Q000494:pharmacology*; D004347:Drug Interactions; D005029:Ethylenediamines / Q000494:pharmacology*; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects*; D010646:Phentolamine / Q000494:pharmacology; D011188:Potassium / Q000494:pharmacology; D014309:Tripelennamine / Q000494:pharmacology*; D014649:Vas Deferens / Q000187:drug effects
D003959:Diamines; D005029:Ethylenediamines; D014309:Tripelennamine; D003983:Dibenzylchlorethamine; C037337:N,N-dimethyl-N',N'-dibenzylethylenediamine; C037338:N,N-dibenzyl-N',N'-dimethyl-1,2-propanediamine; D000109:Acetylcholine; D011188:Potassium; D002118:Calcium; D010646:Phentolamine