摘要
目的观察外源性雌激素(苯甲酸雌二醇,EB)、特异性雌激素α受体(ERα)激动剂(PPT)、特异性雌激素β受体激动剂(DPN)对青春期发育大鼠下丘脑KiSS-1、ERα基因表达的影响。方法将40只SD大鼠随机分为4组:EB组、PPT组、DPN组、自然发育组,于日龄16～20 d连续5 d,EB组、PPT组、DPN组分别注射对应的药物,自然发育组只观察不干预,检查大鼠阴道开口(VO)情况,于VO 2 d后处死,实时荧光定量PCR检测其下丘脑KiSS-1及ERαmRNA的表达,ELISA检测氯化钾(KCl)刺激前后下丘脑培养液促性腺激素释放激素(GnRH)的分泌量。结果各干预组大鼠VO时间均较自然发育组提前[(22.4±1.2)d、(22.8±1.1)d、(27.5±2.3)d vs(31.8±0.8)d,P<0.01];自然发育组KiSS-1 mRNA及ERαmRNA的表达较各干预组均显著增高[KiSS-1 mRNA:(3.95±1.84)vs(0.66±0.39)、(2.08±0.37)、(1.43±0.33),P<0.01;ERαmRNA:(5.51±1.86)vs(0.74±0.46)、(3.85±1.67)、(2.98±1.43),P<0.01];KCl刺激前DPN组较EB组、PPT组及自然发育组下丘脑培养液GnRH分泌量明显减少[(39.91±4.83)ng·L-1 vs(45.11±7.01)ng·L-1、(49.17±5.01)ng·L-1、(47.82±7.51)ng·L-1,P<0.05],KCl刺激后各组下丘脑培养液GnRH分泌量均明显增加,各组间无明显差异[(239.47±55.87)ng·L-1、(211.24±38.54)ng·L-1、(208.17±55.33)ng·L-1、(226.58±49.73)ng·L-1,P>0.05]。结论 EB、PPT及DPN均可以促进大鼠下丘脑GnRH分泌,进而启动下丘脑-垂体-性腺轴,使性发育提前。雌激素诱导的大鼠性早熟机制可能与雌激素的非经典非基因作用机制相关。
Objective To observe the effect of estradiol benzoate （ EB ）, selective estrogen receptor α （ ERα ） agonist （PPT） and selective estrogen receptor β agonist（ DPN ） on puberty onset and secretion of gonadoropin - releasing hormone and expression of KiSS - 1, ERα in hy- pothalamus of female rats. Methods Forty female rats were randomly assigned into 4 groups ： EB group, PPT group, DPN group, and normal control group, 10 rats in every group. Rats in every groups except normal control group were subcutaneously administered drug once a day from 16 days old to 20 days old. The vaginal opening（VO） was observed. All rats were sacrificed at 2 days after the day of VO. The expressions of hypothalamie KiSS - 1 mRNA and ERα mRNA were assayed by real time fluorescent quantitative - PCR. The content of gonadotropin - relea-sing hormone（GnRH） in culture solution was determined with enzyme -linked immunosorbent assay before and after the slices stimulating with high KC1, the change of GnRH biosynthesis in hypothalamus was observed. Results Compared with normal control group, the VO in other groups were ahead of time [ （22.4 ± 1.2） d, （22.8 ± l. 1 ） d, （27.5 ± 2.3 ） d vs （31.8 ± 0.8 ） d,P 〈 0.01 ] ; compared with EB group, PPT group and DPN group, the expressions of hypothalamic KiSS - 1 mRNA and ERa mRNA in normal control group increased [ （ 3.95 ± 1.84） vs （0.66±0.39）,（2.08 ±0.37）,（1.43 ±0.33）,P〈0.01;（5.51 ±1.86） vs （0.74 ±0.46）,（3.85 ±1.67）,（2.98 ±1.43）, P 〈 0, 01, respectively ] ; Before stimulated with high KC1, the secretion of GnRH in DPN group were fewer than that in other groups [ （39.91 ± 4.83） ng·L^-1 vs（45.11 ±7.01） ng·L^-1,（49.17±5.01） ng·L^-1,（47.82±7.51） ng·L^-1,P〈0.051;after stimulated, there was no statistical significance in the secretion of GnRH in all groups [ （239.47 ± 55.87 ） ng·L^-1, （211.24 ± 38.54） ng·L^-1 , （ 208.17 ± 55.33 ） ng·L^-1, （ 226.58 ± 49.73 ） ng·L^-1, P 〉 0.05 ]. Conclusions EB and PPT, DPN may accelerate the stimulation of hypothalamus - pituitary - ovary axis by increasing the secretion of GnRH, and affect the pubertal development. The mechanism of precious puberty induced by exogenous estrogen may be a nonclassical, nongenomie pathway.
出处
《实用儿科临床杂志》
CAS
CSCD
北大核心
2012年第20期1566-1568,共3页
Journal of Applied Clinical Pediatrics
基金
江苏省自然科学基金(BK2009448)
