Adrenomedullin induces penile erection in the cat.
The present study was undertaken to investigate the effects of intracavernosal injections of adrenomedullin, a novel hypotensive peptide, on penile erection in anesthetized cats. Responses to adrenomedullin were compared to those elicited by intracavernosal injection of the control triple-drug combination (1.65 mg papaverine, 25 micrograms phentolamine, and 0.5 microgram prostaglandin E1). Intracavernosal injections of adrenomedullin in doses of 0.1-1.0 nmol elicited dose-related increases in cavernosal pressure and penile length. The maximal effect of adrenomedullin injection on cavernosal pressure was an 8-fold increase in pressure, which was 74% of that induced by the triple-drug combination. The maximal effect on penile length was a 43% increase when compared to baseline value, which was comparable to that induced by the triple-drug combination. The duration of the peak pressure and total duration of the peptide effect were significantly shorter in response to the 1 nmol dose of adrenomedullin than was observed with the control triple-drug combination. Intracavernous injection of the control triple-drug combination resulted in a significantly greater decrease in systemic arterial blood pressure than did adrenomedullin. Erectile responses to adrenomedullin were not altered following administration of the nitric oxide synthase inhibitor. N omega-nitro-L-arginine, at a time when erectile responses to acetylcholine were significantly reduced. These data demonstrate that intracavernous injection of adrenomedullin induces a short-lived erection in cats that is not due to the release of nitric oxide.
Champion
H C
HC
Department of Pharmacology, Tulane University School of Medicine, New Orleans, LA 70112, USA.
Wang
R
R
Shenassa
B B
BB
Murphy
W A
WA
Coy
D H
DH
Hellstrom
W J
WJ
Kadowitz
P J
PJ
D053607:Adrenomedullin; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002415:Cats; D004305:Dose-Response Relationship, Drug; D008297:Male; D009569:Nitric Oxide / Q000502:physiology; D010410:Penile Erection / Q000187:drug effects*; D010455:Peptides / Q000494:pharmacology*
D010455:Peptides; D053607:Adrenomedullin; D009569:Nitric Oxide