THE BODY-WEIGHT AND SKELETAL GROWTH OF FE MALE RATS AFTER OVARIECTOMY

The body weight gain and growth of tail and tibia were investigated in ovariectomized female rats to ascertain whether the increased skeleta l growth after ovariectomy takes place at the same time as the increas ed body weight gain. Female rats were ovariectomized on the 30th day o f age; half of them was killed on the 60th day of age and the other ha lf was killed on the 130th day of age. The body weight and tail length were significantly higher in the ovariectomized females than in intac t females from the 60th day of age (Figs. 1, 2). The ovariectomized an imals had higher body weight gain and tail length increment, in compar ison with intact animals, mainly between die 40th and 60th day of age (Tabs. I, II). After the 90th day of age the body weight gain and tail length increment were, no longer significantly higher in ovariectomiz ed animals than in intact animals, although the ovariectomized females maintained the significantly higher body weight and tail length till the end of the experiment (130th day of age). The length of tibia was larger in ovariectomized animals if compared with controls, on the 60t h as well as on the 130th day of age. However, the rate of longitudina l growth of tibia, measured (by tetracycline method) between the 57th and 59th day and between the 127th and 129th day of age, was significa ntly higher in ovariectomized animals only in the first period of meas urement (Tab. III). The results suggest that changes in body weight ga in after ovariectomy are parallel to the changes of skeletal growth - they are higher for a short time after ovariectomy and later they retu rn to the level of intact females.