Nicotine Delays the Ovulatory Surge of Luteinizing Hormone in the Rat

Abstract

Nicotine tartrate administered to rats on the afternoon of vaginal proestrus delayed the ovulatory surge of luteinizing hormone (LH) output from the pituitary gland. Ovulation was completely blocked by sequential treatment with nicotine and a central nervous depressant, pentobarbital, under conditions in which neither drug alone would prevent LH release. The principal site of nicotine's antigonadotropic action, therefore. appears to be the central nervous system.