Lack of effects for low dose levels of bisphenol A and diethylstilbestrol on the prostate gland of CF1 mice exposed in utero

vom Saal ct at (Proc. Natl Acad Sci 94, 2056-2061, 1997) have reported that low dose exposure (0.02 2 mu g/kg/day) of CF1 mice to diethylstilbestrol ( DES) in utero led to increases in the prostate gland weight when the pups r eached 8 months of age. Nagel et al. (Environ. Health Perspect. 105, 70-76, 1997) reported similar effects in CF1 mice at 6 months of age after exposu re in utero to low dose levels (2 and 20 mu g/kg/day) of bisphenol A (BPA). vom Saal et al, (Toxicol. Indust. Health 14(1/2) 239-260, 1998) subsequent ly reported reduced sperm efficiency (daily sperm production per gram teste s) in a subset of the BPA animals for which enlarged prostates had been obs erved. These three experiments have been repeated in a single experiment th at was terminated when the offspring reached 6 months of age. No statistica lly significant effects on prostate weight or sperm efficiency were recorde d for offspring of animals exposed to either DES (0.2 mu g/kg/day) or BPA ( 2 and 20 mu g/kg/day) in utero. Significant dam effects were seen for sever al of the assay parameters indicating that the litter, as opposed to the in dividual, should be considered as the statistical unit in such experiments. A statistically significant increase in body weight was recorded for the l ow dose BPA male offspring. Females from the study underwent normal sexual maturation and showed no significant differences in reproductive tissue wei ghts at termination and the mean day of vaginal opening. The possible reaso ns for this failure to confirm the earlier reported effects for DES and BPA at these low doses are discussed. (C) 1999 Academic Press.