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

本实验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-性腺轴的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的分泌。通过给新生雄性大鼠注射山羊LHRH抗血清，观察LHRH抑制对雄性大鼠生育力的影响。结果表明，出生后6天接受LHRH抗血清的雄性大鼠睾丸精子生成正常。当它们受到发情雌性的挑战时，它们几乎没有表现出交配行为，也没有交配。抗LHRH治疗组大鼠视前区的性二形核面积较正常组小，较正常组稍大。综上所述，在中枢神经系统性分化关键期抑制LHRH会导致成年后男性阳萎。一种雌激素内分泌干扰物辛基酚，对出生后第0天至第5天的新生雌性大鼠有影响。成年后，摘除卵巢，注射雌二醇-17β，观察促性腺激素释放高峰的发生情况。辛基酚处理的雌鼠在注射雌二醇后的晚上没有出现黄体生成素高峰。当用成年正常雄性大鼠攻击时，辛基酚处理的雌性大鼠的前凸商数及其强度均显著降低，视前区的性二形核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.