Inhibition of penile erection in rats by a long-acting somatostatin analogue, 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 pentobarbital. A cannula was placed in the trachea and the femoral vein cannulated 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 unilaterally using bipolar silver-wire electrodes: the stimulation was repeated every 15 min for 1 h. Twenty animals were divided into two equal groups; after measuring penile erection to obtain basal values, the animals received either saline or 50 mu g SMS 201-995 over 1 h and 30 min later. the stimulation was repeated. Results After administering SMS 201-995 or saline, the levels of penile erection reduced linearly in both groups, but SMS 201-995 caused a greater decrease than in the control group (P < 0.05) and from baseline (P < 0.01) at all times, Conclusion SMS 201-995 inhibits penile erection in rats and the systems may serve as an in vivo animal model for further investigation.