The present study has been carried out to elucidate the antiestrogenic effects of tamoxifen on RNA and protein synthesis in uteri of immature rats. Immature female Sprague-Dawley rats were allocated into 4 groups and injected with 5 micro g of estradiol-17 beta, 50 micro g of tamoxifen, a combination of both, or vehicle only subcutaneously three times with an interval of 24 hrs respectively. The specific activities of 3H-uridine incorporation into uterine RNA and those of 3H-leucine incorporation into uterine protein were measured before and 1, 3, 6, 12, 24, 48 and 72 hrs after the above treatments

Sprague-Dawley rats received subcutaneous injections of gentamicin sulfate, 50 and 100mg/kg for 3, 7 and 10 days. The hematological and blood chemical values were determined. Kidneys were examined histologically and ultrastructurally. The serum values of aspartate transaminase, blood urea nitrogen and creatinine in the rats administered gentamicin, 50 and 100mg/kg/day were significantly increased than those in the control. The ratio of kidney weight to body weight was significantly increased in the rats injected gentamicin, 100mg/kg for 10 days than those in the control

The present study was undertaken to investigate the development of early embryos, the implantation rate in immature rats superovulated by transplantation of a pituitary gland. Thirty-day-old male rats were performed orchidectomy 15 days before removal of each pituitary orchidectomy 15 days before removal of each pituitary gland. A pituitary gland was transplanted under the right kidney capsule of 28-day-old female rat between 0700 and 1000h on the starting day of experiment which was designated as Day -2. Control rats were administered 4 IU PMSG at 1000 on day -2. Some of rats used to experiment were sacrificed to examine the changes of ovarian and uterine weights on days -2, -1, 0, 1, 2, 3 and 5. Other rats were sacrificed to recover the ova and observe the ovaries on Days 1, 2, 3 and 5. The implantation sites were counted on Days 8