Pharmacological effects of adenosine on canine penile erection.
We investigated the pharmacological effects of adenosine on canine penile erection in vivo. Intracavernous injection of adenosine induced a full erection, which was unaffected by hexamethonium and atropine. The erectile response induced by adenosine was augmented by intracavernous pretreatment with dipyridamole and markedly depressed by theophylline. The erectile response induced by cavernous nerve stimulation was also enhanced by dipyridamole and reduced by theophylline. The combination of acetylcholine and adenosine, when injected intracavernously, induced a full erection, and the effect of these drugs was not additive but synergistic. These results suggest that penile erection induced by adenosine is due to a direct relaxing effect on cavernous smooth muscle. We propose that adenosine plays a cooperative role with acetylcholine and also has a physiological role as a neuromodulator in canine penile erection.
Takahashi
Y
Y
Department of Urology, University of California School of Medicine, San Francisco 94143.
Ishii
N
N
Lue
T F
TF
Tanagho
E A
EA
D000109:Acetylcholine / Q000008:administration & dosage; D000241:Adenosine / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D001783:Blood Flow Velocity / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects; D002426:Cavernous Sinus / Q000187:drug effects / Q000502:physiology; D004176:Dipyridamole / Q000008:administration & dosage; D004285:Dogs; D004347:Drug Interactions; D004558:Electric Stimulation; D007267:Injections; D008297:Male; D009126:Muscle Relaxation / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects; D010410:Penile Erection / Q000187:drug effects* / Q000502:physiology; D013806:Theophylline / Q000008:administration & dosage
D004176:Dipyridamole; D013806:Theophylline; D000241:Adenosine; D000109:Acetylcholine