INHIBITION OF PENILE ERECTION IN RATS BY A LONG-ACTING SOMATOSTATIN ANALOG, OCTREOTIDE (SMS-201-995)

Objective To assess the effect of a new somatostatin analogue ISMS 201 -995, octreotide) on erectile function in rats, Materials and methods Animals were fasted and anaesthetized intraperitoneally with pentobarb ital. A cannula was placed in the trachea and the femoral vein cannula ted for intravenous infusion. The hypogastric and pelvic nerve, major pelvic ganglion, and the nerve fibres to the lower genitourinary tract were identified. In 20 animals, these nerves were stimulated unilater ally using bipolar silver-wire electrodes: the stimulation was repeate d every 15 min for 1 h. Twenty animals were divided into two equal gro ups; after measuring penile erection to obtain basal values, the anima ls received either saline or 50 mu g SMS 201-995 over 1 h and 30 min l ater. the stimulation was repeated. Results After administering SMS 20 1-995 or saline, the levels of penile erection reduced linearly in bot h groups, but SMS 201-995 caused a greater decrease than in the contro l group (P < 0.05) and from baseline (P < 0.01) at all times, Conclusi on SMS 201-995 inhibits penile erection in rats and the systems may se rve as an in vivo animal model for further investigation.