SD雌性大鼠性发育早期性器官等脏器和性激素的动态变化

Dynamic Development of Organs and Serum Sex Hormone Levels in Normal Pre-pubertal Female Sprague-Dawley Rats

目的探讨正常SD雌性大鼠性成熟前不同日龄段的脏器与促黄体生成素(LH)、促卵泡素(FSH)、雌二醇(E2)等性激素的变化及其关系。方法从生产群中取出60窝密度状态一致的SD大鼠,在不同日龄随机选取雌性大鼠,检测152、5、32、40日龄时大鼠体重、主要脏器指数,子宫、卵巢组织变化和15、253、2、40、60日龄大鼠血清LH、FSH、E2水平。结果记录了SD雌性大鼠性成熟前各脏器指数和卵巢、子宫组织变化,结果显示大鼠卵巢、子宫的增长速度大于体重的增长,而其他脏器增速大都小于体重的增长。本研究还记录了血清LH、FSH、E2水平在不同日龄段的变化规律,表明血清LH、E2浓度在32日龄时出现较为明显升高。结论不同日龄大鼠脏器指数的动态变化提示大鼠性器官在性发育早期得到机体的优先发育。血清LH、E2水平在32日龄时有了明显升高,提示性腺轴功能已经激活。60日龄大鼠血清性激素水平的波动类似于动情周期的规律性变化,推测大鼠在60日龄前即已进入性成熟,这些结果将为大鼠性发育的相关研究提供重要的参考数据。

Objective To investigate the organ coefficient and histophysiological changes and to compare the levels of serum LH, FSH and E2 in the early stage of pre-pubertal Sprague-Dawley rats. Methods SI） rats were randomly divided into 5 groups with 30 each. Rats from groups 1 - 5 were sacrificed for measurement of body weight, organ coefficient, histophysiological changes of ovaries and uterus on 15, 25, 32 and 40-day-old as well as serum LH, FSH and E2 levels on 15, 25, 32, 40 and 60- day-old, respectively. Results the organ coefficient and histophysiological difference and levels of serum LH, FSH and E2 were compared at different ages of SD rats. Results indicated that the growing rate of ovary and uterus were much higher than that of body weight, whereas, the other organs were relatively lower than that of the body weight. Serum LH and E2 levels in 32-day-old rats were increased when compared to the levels on 15 and 25-day-old. Conclusions The dynamic development of organ coefficients on 15, 25, 32 and 40-day-old suggested that the sexual organs were given priority to development during early stage of pre-puberty in SD rats. High levels of LH and E2 on 32-day-old recorded in the present manuscript indicated that hypothalamie- pituitary-gonadal axis was activated in 32-day-old rats. Besides, serum sex hormone levels on 60-day-old were similar to the regular change in estrous cycle, suggesting the entrance of sex maturity. These results supply the reference data for further research on sex maturation in SD rats.