APOMORPHINE VERSUS MATING-BEHAVIOR IN TESTING ERECTILE CAPABILITIES OF DIABETIC RATS

Objectives. Diabetes mellitus (DM) is an important cause of organic im potence. It is estimated that 35% to 75% of diabetic patients are impo tent. In the present study we investigated the effect of experimentall y induced diabetes (streptozocin 60 mg/kg, intraperitoneally, for 9 we eks) on sexual behavior and compared it to the apomorphine (APO) bioas say test. Methods. Libido, genital refer excitability, and penile comp etence as measured by different parameters of mating behavior were red uced with DM (P < 0.05 versus control for each parameter). Results. Of 17 diabetic rats, 53% (9 rats) experienced positive mating behavior ( either intromission or ejaculation) compared with 82.4% (14 rats) posi tive response to the APO bioassay test. Moreover, combined apomorphine injection and mating sexual testing in diabetic rats that achieved in tromission but not ejaculation or those that did not achieve intromiss ion in the initial mating, considerably improved the performance of th ese rats. Conclusions. We suggest that the APO test alone or, even bet ter, combined APO injection and sexual testing are superior in eliciti ng maximum erectile capabilities of the diabetic rats than mating test ing alone.