Noradrenergic system interacts with genital reflexes induced by cocaine in paradoxical sleep-deprived male rats.
Different doses of alpha-1, alpha-2, beta-1, and beta-2 adrenoceptor agonists or antagonists were administered to paradoxical sleep-deprived (PSD) rats prior to cocaine administration. Methoxamine reduced the percentage of rats displaying erection, whereas prazosin did not. Yohimbine significantly decreased this percentage. For beta-1 adrenoceptor drugs, both compounds reduced the percentage of rats displaying erection at the highest dose; beta-2 adrenoceptor drugs had no effect. Except for clonidine, all drugs significantly reduced the frequency of erection. Ejaculation was significantly decreased following yohimbine and beta-1 drugs, whereas it was completely abolished by prazosin. The results showed that noradrenergic drugs inhibited genital reflexes in PSD rats, with distinct responses in relation to their respective action over the adrenoceptor.