Inhibition of 3,4-diaminopyridine-induced coronary oscillation by adenyl compounds.
3,4-Diaminopyridine (DAP) contracted the isolated canine coronary arteries rhythmically. Together with the contractions, plateau potentials which were often preceded by spike-like potentials were recorded with glass microelectrodes. Adenosine inhibited both the DAP-induced contraction and the depolarization. ATP, ADP and AMP inhibited the contraction similarly. Cyclic AMP had a slight inhibitory effect on the contraction and dibutyryl cyclic AMP had no effect on it. Aminophylline antagonized the inhibitory effect of adenosine, ATP and ADP. Dilazep potentiated the effect of adenosine and indomethacin did not affect it. These results show that adenosine occupies the P1-purinoceptor and blocks the DAP-induced repetitive contractions of isolated canine coronary arteries by suppressing the rhythmic depolarization.
D015761:4-Aminopyridine / Q000031:analogs & derivatives*; D000227:Adenine Nucleotides / Q000494:pharmacology*; D000241:Adenosine / Q000494:pharmacology*; D000077770:Amifampridine; D000628:Aminophylline / Q000494:pharmacology; D000631:Aminopyridines / Q000037:antagonists & inhibitors*; D000818:Animals; D003331:Coronary Vessels / Q000187:drug effects*; D004109:Dilazep / Q000494:pharmacology; D004285:Dogs; D004347:Drug Interactions; D066298:In Vitro Techniques; D007213:Indomethacin / Q000494:pharmacology; D008564:Membrane Potentials / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects
D000227:Adenine Nucleotides; D000631:Aminopyridines; D000628:Aminophylline; D015761:4-Aminopyridine; D004109:Dilazep; D000241:Adenosine; D000077770:Amifampridine; D007213:Indomethacin