EFFECTS OF PINACIDIL UPON PENILE ERECTILE TISSUE, INVITRO AND INVIVO

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 (10‐5‐10‐3M) 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 10‐5‐10‐3M. 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 10‐3M. 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. 1990 Nordic Pharmacological Society