Serotonin type 2 antagonists inhibit lordosis behavior in the female rat: reversal with quipazine.

The theory that activation of serotonin type 2 (5-HT2) receptors facilitates lordosis behavior in the female rat was tested. The 5-HT2 antagonists pizotefin, cyproheptadine, metitepine, and ketanserin were found to inhibit lordosis behavior in ovariectomized rats that had been primed with estradiol benzoate and progesterone. Pipamperone was ineffective. The 5-HT2 agonist quipazine was ineffective alone, but it reversed the inhibitory effects of pizotefin, cyproheptadine, and ketanserin. It did not reverse the effects of metitepine. The results support the theory of a facilitatory role for 5-HT2 receptors in lordosis behavior.