Effect of polychlorinated biphenyls on several endocrine reproductive parameters in the female rhesus monkey.

Female rhesus monkeys (Macaca mulatta) ingested gelatin capsules containing daily doses of 0 (control), 5, 20, 40, or 80 micrograms of Aroclor 1254/kg/day (PCB) which was dissolved in corn oil plus glycerol. After approximately two years of dosing and when the monkeys were near an adipose tissue PCBs equilibrium, each dose group of 16 animals was randomly divided into two test groups. Daily blood samples from both groups were acquired for estrogen and progesterone analysis during one menstrual cycle. Test group 1 was sampled during February-March and test group 2 during August-September. Serum estrogen and progesterone concentrations in monkeys dosed with PCBs were equivalent to control values with the exception of the luteal phase progesterone levels in the 20 and 80 micrograms/kg/day dosed monkeys in test group 1. There was no difference in menstrual cycle length between control and treated monkeys for the month sampled, however, menses duration was marginally longer in the 80 micrograms/kg/day dose group. There were no apparent treatment related differences in the incidence of anovulatory cycles nor on the temporal relationship between the estrogen peak and menses onset, menses end or the progesterone peak.