Testicular toxicity of dietarily or parenterally administered bisphenol A in rats and mice

Male Crj:Wistar rats, HsdHot:Holtzman SD rats, Crj:CD-1(ICR) mice and C57BL/6CrSlc mice were administered bisphenol A (BPA) in the diet at a level of 0 (control) and 0.25% for 8 weeks. Daily BPA intake was about 200 and 400 mg/kg for rats and mice, respectively. No conspicuous signs of general or reproductive toxicity were observed after administration in any strain of these animals. Serum testosterone concentrations were not decreased in BPA-fed rats and mice. Successive subcutaneous administration of BPA at a dose of 200 mg/kg/day for 4 weeks significantly decreased the testis, epididymis, prostate and seminal vesicle weights, and the testicular daily sperm production in Jcl:Wistar rats. Successive intraperitoneal administration of BPA at a dose of 20 mg/kg/day for 4 weeks decreased the prostate and seminal vesicle weights but not the testis or epididymis weights. An intraperitoneal dose of 2 mg BPA/kg/day did not cause any toxicity. These results indicate that dietarily administered BPA is less toxic to most strains of rats and mice, and the maximum non-toxic dose and/or minimum toxic dose may be about 200 mg/kg/day. Subcutaneous or intraperitoneal BPA is much more toxic on male reproductive and sex accessory organs than dietary.