Cocaine impairs follicular phase pulsatile gonadotropin secretion in rhesus monkeys

Objective:To assess cocaine's effect on follicular phase pulsatile gonadotropin secretion in normally cycling rhesus monkeys.Methods:Sixteen monkeys were paired by body weight and randomized to receive intravenous saline (n = 8) or cocaine (4 mg/kg, n = 8) daily on cycle days 2 to 14. Monkeys were chronically cannulated to allow frequent blood collections without anesthesia. Blood samples were obtained every 15 minutes for 8 hours in early (EFP; cycle days 1 to 5); mid- (MFP; cycle days 6 to 10), and late (LFP; cycle days 11 to 15) follicular phase. Plasma concentrations of LH, FSH, and estradiol-17β (E2) were determined by radioimmunoassay. Pulses were identified by cluster analysis. Statistical differences were determined by analysis of variance (ANOVA) and Sidak's multiple comparison test.Results:Seven out of eight monkeys in the control group demonstrated timely ovulation. Only one monkey in the cocaine-treated group ovulated. Similar gonadotropin pulse intervals (7 to 90 minutes) were observed throug...