Polychlorinated biphenyls and nutritional restriction: their effects and interactions on endocrine and reproductive characteristics of male white mice.

Aroclor 1254, a polychlorinated biphenyl (PCB), was fed to adult male white mice in an ad libitum diet at levels of 50 and 200 ppm and in a restricted diet (50% of the amount consumed ad libitum) at levels of 100 and 400 ppm to compare effects and possible interactions of PCB ingestion and feed restriction on select endocrine and reproductive characteristics and barbiturate-induced sleeping times. The mice were maintained on the two nutritional levels for 30 days, whereas the PCB was incorporated into the diets during the final 15 days only. PCB ingestion significantly increased paired adrenal gland weights, liver weights, and plasma corticoid concentrations. In addition, PCB-fed mice exhibited reduced testicular spermatozoa concentrations and pentobarbital-induced sleeping times. PCB feeding did not affect final body weights or the weights of the reproductive organs. Feed restriction reduced the weights of the seminal vesicles, preputial glands, testes, and final body weights. Feed restriction increased adrenal weights, pentobarbital-induced sleeping time, and plasma corticoid concentrations. Liver weights and testicular spermatozoa concentrations were not affected by feed restriction. The PCB-associated reduction in sleeping time was greater in feed-restricted mice than in mice allowed food ad libitum. The effect on plasma corticoid concentrations was greatly intensified in mice subjected to PCBs and feed restriction simultaneously as compared to mice subjected to feed restriction or PCB feeding separately.