The Effect of Polybrominated Biphenyl (PBB) on Testes, Adrenal, and Pituitary Function in the Rat

In an earlier study we reported a dose- and time-dependent effect of polybrominated biphenyls (PBB) on thyroid function in the rat. In the present study we report the effects of PBB administration to male rats on testis, adrenal, and pituitary endocrine function. PBB were administered by gavage at 1, 3, or 6 mg/kg/day for 20 days. There was no effect of PBB administration on adrenal or testis weights, despite a significant increase in liver weight at all dosages, nor were plasma corticosterone or testosterone levels altered by treatment. At the highest PBB dosage used, there was a significant reduction in plasma prolactin levels. After 20 days of PBB administration at 3 mg/kg/day, tissue concentration of PBB in the testes was only 8.7 ± 3.7 μg/g, while concentration in the adrenal was 93.7 ± 15.3 μg/g, much greater than levels reported earlier for thyroid and liver. After cessation of PBB and 5 months of dietary restriction treatment, adrenal PBB concentration significantly increased to 481.1 ± 105.9 μg/g, suggesting a mobilization from adipose tissue and a preferential sequestration in the adrenal glands.