The following abstract presents results of a study conducted by a contract laboratory for the National Toxicology Program (NTP). The findings may or may not have been peer reviewed and were not evaluated in accordance with the Explanation of Levels of Evidence for Reproductive Toxicity criteria (see http://ntp.niehs.nih.gov/ntp/htdocs/levels/09_3566_NTP_ReproTOX_R1.pdf or with the Explanation of Levels of Evidence for Developmental Toxicity criteria (see http://ntp.niehs.nih.gov/ntp/Test_info/NTP_DevTox20090507.pdf) established by the NTP in March 2009. The findings and conclusions for this study should not be construed to represent the views of the NTP or the US Government.
Bisphenol A (BPA) was examined in the Reproductive Assessment by Continuous Breeding protocol using Swiss mice. Continuous exposure to BPA for 2 weeks via subcutaneous Silastic® implants containing 0, 6.25, 12.5, 25, 50 or 100 mg BPA during Task 1 (dose range-finding study) caused no overt toxicity, but did seem to increase the weight of the reproductive tract in high dose females. Although this increase in reproductive tract weight was not statistically significant, it suggested possible estrogenic activity of the test chemical. Therefore, dose levels of 0, 25, 50 and 100 mg of BPA, given via subcutaneous Silastic® implants, were selected for Task 2 (continuous breeding).
During Task 2 several animals in each treatment group expelled their implants through cutaneous lesions that developed directly over the implants or at the site of the initial incision. When this occurred, animals were reimplanted with Silastic® tubing containing the original amount of BPA; several animals received new implants on three different occasions during Task 2. Although some of the reproductive parameters. measured during Task 2 differed significantly among treatment groups, these differences appeared to be due to chance alone. Because the Silastic® implants tended to be expelled and since they appeared to release too little BPA to cause generalized or reproductive toxicity, the present study was terminated at the conclusion of Task 2.
Under the conditions of this study, no effects of BPA on
fertility and reproduction in male and female CD-l mice were
observed. Further studies at higher doses and by other means
of administration are required to investigate the
reproductive toxicity of BPA.
Report Date: January 1984