Study on the effects of endocrine disruptors on development and differentiation of gonads and central nervous system.

我们主要研究了内分泌干扰物对大鼠中枢神经系统性分化的影响。1）新生期LHRH的分泌对大鼠下丘脑-垂体-性腺轴雄性性功能的正常发育至关重要。已知一些内分泌干扰物具有雌激素样作用并能够抑制LHRH分泌。本研究通过在雄性大鼠出生后注射抗山羊LHRH抗血清，观察LHRH抑制对雄性大鼠生育力的影响，结果表明，雄性大鼠出生后6天注射LHRH抗血清，睾丸精子生成正常。当它们与发情期的雌性动物一起攻击时，它们几乎没有交配行为，也没有交配。抗LHRH组雄性视前区性二形核的面积比正常雄性小，比正常雌性稍大。结论：在中枢神经系统性分化的关键期，LHRH的抑制可能导致成年期男性阳痿。雌激素性内分泌干扰物辛基酚对出生后0天至5天的新生雌性大鼠的影响。生长至成年后，切除卵巢并注射雌二醇-17 β，观察促性腺激素峰的发生。辛基酚处理的雌性动物在雌二醇注射后的晚上未显示LH峰。在成年雄性大鼠的刺激下，辛基酚组雌性大鼠的脊柱前凸系数和强度均显著降低，视前区性二形核的面积大于正常雌性大鼠。

We have investigated mainly about the effects of endocrine disruptors on sexual differentiation of CNS in rats.1) LHRH secretion during neonatal period is critical for normal development of male sexual function in hypothalamo-pituitary-gonadal axis in rats. Some of endocrine disruptors are known to have estrogenic action and be able to suppress LHRH secretion. We evaluate the effects of LHRH suppression on the fertility of male rats by injecting anti-LHRH antiserum raised in goats during neonatal of male rats.In the results, male rats received LHRH antiserum for six days after birth showed normal sperm production in their testes. When they were challenged with estrous females, they showed little mating behavior and showed no copulation. Areas of the sexual dimorphic nucleus of preoptic area in the anti-LHRH treated males seemed smaller than those of normal males and a little larger than normal females. In conclusion, LHRH suppression during the critical period of sexual differentiation in central nervous system would result in the impotence of males at adulthood.2) We injected s.c. an estrogenic endocrine disruptor, octylphenol, to neonatal female rats from day 0 to day 5 after birth. After growing to adult, they were ovariectomized and injected estradiol-17β to see the occurrence of gonadotropin surges. Octylphenol treated females did not show LH surge at the evening after estradiol injection. When they were challenged with mature normal male rats, both the lordosis quotient and its intensity were significantly low in octylphenol treated females.The areas of the sexual dimorphic nucleus in the preoptic area were larger than those od normal female rats.