Effects of pinacidil upon penile erectile tissue, in vitro and in vivo.
The effect of pinacidil, a new antihypertensive vasodilator, was studied in vitro upon human and porcine Corpus cavernosum and in vivo upon simian Corpus cavernosum. In vitro, pinacidil incubation (10(-5)-10(-3) M) was found to induce a concentration-dependent inhibition of the tissue response to norepinephrine (NE) and high potassium (K+). Likewise a concentration-related relaxation of the tissue, precontracted with either NE or K+, was seen using pinacidil 10(-5)-10(-3) M. Depending on the concentration applied, spontaneous activity as well as tone and amplitude of the contractions were reduced until total relaxation of the tissue was obtained with a pinacidil incubation of 10(-3) M. In vivo, 5 mg pinacidil in 0.3 ml solution was injected intracavernosally in 17 monkeys. Sixteen monkeys developed tumescence and 10, rigidity of the penis as well. Only one of 5 showed a decrease in the systemic blood pressure. Pinacidil might be of clinical interest as an agent facilitating erection when given intravernosally.
Giraldi
A
A
Panum Institute, University of Copenhagen, Denmark.
Wagner
G
G
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002521:Cercopithecus; D006146:Guanidines / Q000494:pharmacology*; D006801:Humans; D008252:Macaca fascicularis; D008297:Male; D009638:Norepinephrine / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D010410:Penile Erection / Q000187:drug effects*; D010413:Penis / Q000187:drug effects*; D020110:Pinacidil; D011188:Potassium / Q000037:antagonists & inhibitors / Q000494:pharmacology; D013552:Swine
D006146:Guanidines; D020110:Pinacidil; D011188:Potassium; D009638:Norepinephrine