Influence of phytoestrogens on development of reproductive functions

本实验研究了植物雌激素古雌醇、染料木素和白藜芦醇对大鼠性别分化和生殖行为的影响。植物雌激素对脑功能男性化的影响(1)库美雌醇（CM）的作用：出生后第5天单次注射库美雌醇3mg，雌性大鼠阴道开口加速，阴道涂片无循环改变，卵巢小而无黄体，前凸活性低，与注射雌二醇1mg相同。另一方面，注射染料木素时没有观察到任何影响。(2)白藜芦醇（resveratrol， RTL）的作用：出生后第5天单次注射5mg白藜芦醇可引起少量大鼠阴道涂片无循环变化，但大多数雌性大鼠无循环变化。注射RTL对前凸活动无影响。(3)黄体酮对库米孕酮的男性化作用的预防：已知黄体酮可以抑制大脑中雌激素的功能。本实验在母鼠出生后第5天同时注射CM 3mg和孕酮0.5mg，对阴道开口、阴道涂片和前凸活动均无影响。这表明黄体酮也可以阻止植物雌激素的男性化作用。植物雌激素对成年雌性大鼠前凸和母性行为的影响。(1)性行为：去卵巢大鼠注射CM后44小时，分别注射CM 1mg和黄体酮0.5mg，观察前凸行为。结果没有观察到任何影响。即使给去卵巢大鼠注射亚阈值剂量的雌激素，也没有观察到任何影响。(2)母性行为：每天注射1mg苯甲酸雌二醇，连续10天，会加速母性行为的发生，而去卵巢大鼠注射lmg CM则不会。这些结果表明，植物雌激素对新生期雌性大鼠的雄性化大脑有效，但对成年雌性大鼠的生殖行为没有促进作用。

In this experiment, effects of phytoestrogens, coumestrol, genistein and resveratrol, on sexual differentiation and reproductive behaviors were examined in the rat.1. Effects of phytoestrogens on masculinization of the brain functions(1) Effects of coumestrol(CM) : Single injection with 3mg CM on day 5 after birth induced acceleration of vaginal opening, acyclic change in vaginial smear, small ovaries without corpus luteum and low lordotic activity in female rats, as injection with 1mg estradiol. On the other hand, no effects were observed when injected with genistein.(2) Effects of resveratrol(RTL) : Single injection with 5mg RTL on day 5 after birth induced acyclic change in vaginal smear in a few rats, but not in most female rats. Lordotic activity was not influenced by injection with RTL.(3) Prevention of masculinizing effects of coumestrol by progesterone : Progesterone is known to suppress functions of estrogen in the brain. In this experiment, simultaneous injection with 3mg CM and 0.5mg progesterone to female pups on day 5 after birth induced no effect on vaginal opening, vaginal smear and lordotic activity. This indicates that progesterone also can prevent masculinizing effect of phytoestrogens.2. Effects of phytoestrogens on lordosis and maternal behavior in adult female rats.(1) Sexual behavior : Ovariectomized rats were injected with 1mg CM and 0.5mg progesterone 44 hrs after injection of CM and lordosis behavior was observed. As a result no effects were observed. No effects were observed even when injected those in ovariectomized rats treated of substhresthold dose of estrogen.(2) Maternal behavior : Injections with 1mg estradiol benzoate daily for 10 days accelerated onset of maternal behavior but lmg CM in ovariectomized rats did not.These results indicate that phytoestrogen is effective in mascuilinizing the brain in the neonatal period but not in facilitation of reproductive behaviors in adult female rats.