INHIBITION OF LORDOSIS IN FEMALE HAMSTERS AND RATS BY 8-OH-DPAT TREATMENT

In the present experiments, the ability of the 5-HT1A agonist, 8-OH-DP AT, to inhibit lordosis was determined in ovariectomized hamsters and rats under various hormonal conditions. Systemic administration of 8-O H-DPAT (0.25 mg/kg) significantly inhibited lordosis duration in ovari ectomized hamsters treated on 3 consecutive wk with estradiol benzoate (3 or 10 mu g) and progesterone (500 mu g). Similarly, systemic admin istration of 8-OH-DPAT (0.25 mg/kg) significantly inhibited lordosis f requency in ovariectomized rats treated on 3 consecutive wk with estra diol benzoate (0.25, 0.5, or 25 mu g for 3 days) and progesterone (500 mu g), although females treated with the higher doses of estrogen wer e slightly less inhibited on the second and third wk of testing. Resul ts indicate that the 5-HT1A agonist, 8-OH-DPAT, effectively inhibited lordosis in female hamsters, as well as female rats, under varied horm onal conditions.