GnRH-Induced Regulation of GnRH Receptor Concentration in the Phenobarbital-Blocked Hamster1

Abstract
The effect of exogenous gonadotropin releasing hormone (GnRH) or ovine luteinizing hormone (oLH) on GnRH receptor binding characteristics was determined in the phenobarbital (Phen)-blocked proestrous hamster. Phenobarbital administration at 1130 h prevented the decline in GnRH receptor concentration that occurs normally during the afternoon of proestrus. In the Phenblocked hamster exogenous GnRH induced LH secretion, ovulation, and the decline in GnRH receptors.