大补阴丸治疗雌性大鼠真性性早熟的实验研究

目的:研究大补阴丸对雌性大鼠真性性早熟的治疗作用,并探讨其可能的作用机制.方法:26日龄SD雌性大鼠于每日14:00和16:00皮下注射N-甲基-DL-天冬氨酸(N-methyl-DL-aspartic acid,NMA)40 mg·kg-1建立性早熟模型,同时给予大补阴丸进行干预,通过肉眼观察大鼠阴门开启时间；阴道涂片法观察第1个发情间期出现的时间；取卵巢、子宫称重计算脏器系数；制作常规组织病理切片观察子宫、卵巢的组织形态并计算子宫壁厚度和卵巢黄体个数；检测血清中的E2水平等对大补阴丸对NMA性早熟大鼠的治疗作用进行判定,并通过半定量RT-PCR法检测下丘脑促性腺激素释放激素(GnRH)、G蛋白偶联受体54(GPR54)和Kiss-1 mRNA的表达,探讨大补阴丸的可能作用机制.结果:大补阴丸1.62,3.24 g·kg-1剂量能明显减轻性早熟大鼠的子宫系数(P＜0.05),减少动物阴道开口数(P＜0.01),对子宫壁厚度和黄体生成数均有一定的降低作用(P＜0.05),且能明显下调下丘脑GnRH,GPR54,Kiss-1 mRNA的表达水平(P＜0.05),而对血清E2水平无明显影响.结论:大补阴丸可能通过下调下丘脑Kiss-1/GPR54 mRNA的表达,抑制下丘脑GnRH的合成和释放,从而抑制下丘脑-垂体-性腺轴的启动,达到治疗真性性早熟的目的.

Experimental study on therapeutic effect of Dabuyin Wan on true precocious puberty in eemale rats

Objective: To study the therapeutic effect of Dabuyin Wan on true precocious puberty of female rats and its possible mechanism. Method: Twenty-two-day-old female SD rats were subcutaneously injected with 40 mg·kg^-1N-methyl-DL-aspartic acid (NMA) at 14:00 and 16:00 every day; meanwhile, the rats were given Dabuyin Wan for intervention. Visual inspection was conducted for the time of vaginal opening. The first estrus was observed by yaginal smear test. Their ovaries and uterus were weighed to calculate organ coefficients. Conventional pathological slices were made to observe morphological changes in ovaries and uterus and calculate the thickness of uterine walls and the number of corpus luteums. The level of E2 in serum was detected to assess the therapeutic effect of Dabuyin Wan on NMA precocious puberty in rats. expressions of GnRH, GPR54 and Kiss-1 mRNA in hypothalamus were measured by semi-quantitative RT-PCR to investigate the possible mechanism of Dabuyin Wan. Result: Dabuyin Wan at 3.24 g·kg^-1 and 1.62 g·kg^-1 significantly decreased the organ coefficients in rats with precocious puberty (P<0.05), decrease the number of vaginal openings in rats (P<0.01) and the thickness of uterine walls and the number of corpus luteums (P<0.05), and notably down-regulated expressions of GnRH, GPR54 and Kiss-1 mRNA in hypothalamus (P<0.05), without significant impact on E2 in serum. Conclusion: Dabuyin Wan may inhibit GnRH synthesis and release as well as startup of hypothalamic-pituitary-gonadal axis by down-regulating Kiss-1/GPR54 mRNA expression in hypothalamus, in order to realize the therapeutic effect on true precocious puberty.