Theophylline antagonizes the effect of diazepam on ventricular automaticity.
The effect of diazepam on ventricular automaticity induced by a local injury was investigated in the isolated right ventricle of the rat in the presence of the diazepam central antagonist, RO 15-1788, and of the adenosine antagonist, theophylline. Theophylline but not RO 15-1788 antagonized the inhibitory effect induced by diazepam on ventricular automaticity. The inhibitory effect of adenosine but not that of 2-chloroadenosine was potentiated in the presence of diazepam. The results suggest that the inhibitory effect of diazepam on ventricular automaticity results from the inhibition of adenosine uptake.
Ruiz
F
F
Department of Pharmacology, University of Murcia Medical School, Spain.
Hernández
J
J
Ribeiro
J A
JA
D000241:Adenosine / Q000378:metabolism / Q000494:pharmacology; D000818:Animals; D003975:Diazepam / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D005260:Female; D005442:Flumazenil / Q000494:pharmacology; D006339:Heart Rate / Q000187:drug effects*; D006352:Heart Ventricles / Q000187:drug effects / Q000293:injuries; D066298:In Vitro Techniques; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013806:Theophylline / Q000494:pharmacology*; D016276:Ventricular Function
D005442:Flumazenil; D013806:Theophylline; D000241:Adenosine; D003975:Diazepam