Ovarian Toxicity of 2‐Bromopropane in the Non‐Pregnant Female Rat

Abstract

Ovarian Toxicity of 2‐Bromopropane in the Non‐Pregnant Female Rat: Michihiro Kamijima, et al. Department of Hygiene, Nagoya University School of Medicine—A cluster of patients with amenorrhea, oligospermia and anemia were found among workers in an electronics factory in the Republic of Korea. 2‐Bromopropane was suspected to cause the disorders. This study aimed to clarify its ovarian toxicity in the virgin rat. Female Wistar rats were daily exposed to 0, 100, 300, or 1,000 ppm 2‐bromopropane for eight hours a day for 9 weeks. During the experimental period, vaginal smears were taken everyday to monitor ovarian cyclicity. Tissues were histopathologically examined and plasma concentrations of luteinizing hormone (LH) and follicle‐stimulating hormone (FSH) were determined at the end of experiment. The vaginal smear test showed that the number of normal cycles decreased significantly both in the 300 and 1,000 ppm groups. The histopathological examination revealed dose‐dependent ovarian follicle atresia accompanied by a decreased number of normal antral and growing follicles in the 300 and 1,000 ppm groups. Especially, in the ovaries of rats with persistent estrous smears in the 1,000 ppm group, most of the follicles were atretic and there were no newly formed corpora lutea. There still remained normal antral follicles and corpora lutea in the ovaries of the remaining rats of the group and of the 300 ppm group with constant diestrous and occasional estrous smears. Hormonal examination revealed no statistically significant change in LH or FSH concentrations between any groups. The results showed that 2‐bromopropane has ovarian toxicity in rats, indicating that the secondary amenorrhea in human cases was due to 2‐bromopropane exposure.