Effects of alcohol on E2 beta-stimulated luteinizing hormone in ovariectomized rhesus monkeys

Anovulation is a frequent concomitant of alcohol abuse, but it has been difficult to assess the acute effects of alcohol on ovulation. Estradiol benzoate (E2 beta) can stimulate a luteinizing hormone (LH) surge in ovariectomized monkeys that appears to be associated with increased luteinizing hormone-releasing hormone (LHRH) pulse frequency and amplitude. The acute effects of alcohol (2.5 and 3.5 g/kg) and an isocaloric sucrose control solution on LH and follicle-stimulating hormone (FSH) secretory activity were studied in five ovariectomized monkeys 41 to 51 hours after administration of E2 beta (42 micrograms/kg, IM). Integrated plasma samples were collected at 20-minute intervals over 10 hours. Under sucrose control conditions, LH increased to 445 and 584 ng/ml within 46 to 49.3 hours after E2 beta administration in two monkeys and high-amplitude LH pulses were evident in three monkeys. Alcohol (2.5 and 3.5 g/kg) significantly decreased the number of LH peaks and valleys (p < 0.01). Peak blood alcohol levels averaged 195 and 291 mg/dl. After 2.5 g/kg alcohol, there was no LH surge or LH pulses in four of five monkeys. A delayed LH surge occurred in one monkey 48 to 50.6 hours after E2 beta when blood alcohol levels decreased to 62 mg/dl. After 3.5 g/kg alcohol, no monkey had an LH surge and pulsatile LH release was significantly reduced in comparison to control conditions (p < 0.01). FSH levels remained stable across alcohol and control conditions. These data suggest that alcohol attenuates pituitary release of LH in response to E2 beta stimulation. These findings are consistent with menstrual cycle disruptions observed in alcohol-dependent women, social drinkers, and in a primate model of alcoholism.