EFFECTS OF ACUTE AND LONG-TERM DOMPERIDONE TREATMENT ON PROLACTIN ANDGONADAL HORMONE LEVELS AND SEXUAL-BEHAVIOR OF MALE AND FEMALE RATS

Domperidone (DOMP), a dopamine D-2 blocker that is unable to cross the blood-brain barrier, is an experimental tool used to induce hyperprol actinemia. Acute and long-term DOMP administration was tested in male and female rats for its effects on sexual behavior and plasma gonadal hormone levels. DOMP (4.0 mg/kg) was injected IP either acutely or dai ly for 30 days. Acute treatment failed to modify any behavioral parame ter observed. The 5-day treatment stimulated and the 30-day treatment failed to inhibit sexual behavior of male rats. Serum testosterone lev els were significantly reduced after 30 days of treatment in male rats . The 30-day treatment also inhibited sexual behavior and enhanced pla sma progesterone levels in ovariectomized and intact female rats, resp ectively. The present results may be due to DOMP-induced long-term hyp erprolactinemia. Alternatively, blockade of dopamine peripheral recept ors induced by this treatment may also be responsible for the behavior al changes reported here. Moreover, these data suggest that female rat s are more susceptible than males to the behavioral effects of long-te rm hyperprolactinemia. (C) 1997 Elsevier Science Inc.