Results

Cocaine-induced PE in 90% of PSD rats, 60% of which ejaculated. l-NAME reduced the frequency of erection, but had no effect in the proportion of PSD-cocaine-injected rats displaying this response. l-NAME had no effect in saline groups. l-Arginine in PSD-saline rats reduced the proportion of animals displaying PE at the highest dose and reduced the frequency of PE at all doses in both saline and cocaine groups. The icv administration of l-arginine reduced PE only in PSD-cocaine rats. Results indicate that common to both drugs, whether it was NO synthase (NOS) inhibitor or NO precursor, was their capacity to strongly reduce PE frequency in cocaine-treated rats. Moreover, l-arginine (ip) played a relevant inhibitory role in the erection displayed by PSD rats.