Reproductive abnormalities in the prepubertal jaundiced Gunn rat.

The female, jaundiced Gunn rat has been previously reported to be infertile. This study describes some abnormalities in the reproductive system of the prepubertal jaundiced female rat. Vaginal opening occurred at the time of weaning, which was approximately 7 days earlier when compared to the nonjaundiced female littermates. Following vaginal opening, the jaundiced rat showed persistent vaginal cornification. The estimated age at first ovulation in the jaundiced rat was 52 days. The uteri of jaundiced rats were significantly larger than those of nonjaundiced rats by 17 days after birth. The accelerated uterine growth and the precocious vaginal opening in the jaundiced rat suggest hyperestrogenism. Feeding activated charcoal to jaundiced rats significantly reduced the uterine weight. These results show that the reproductive abnormalities in the jaundiced female rat appear in the prepubertal life and continue during adult life resulting in infertility.