递增负荷运动过程中促性腺激素释放激素受体基因表达的变化

Changes in and Significance of GnRHR mRNA Expression in Rats with Estrous Cycle Dysfunction Induced by Training

目的：探讨运动性动情周期紊乱进程及恢复过程中雌性大鼠下丘脑一垂体一卵巢（HPO）轴各环节促性腺激素释放激素受体（GnRHR）mRNA水平变化的规律及意义。方法：对不同训练周期及恢复过程的大鼠，采用RT—PCR检测其下丘脑、垂体、卵巢、子宫GnRHR mRNA的表达，采用液相平衡竞争放射免疫分析法检测其血清雌二醇（E2）、孕酮（P）水平。结果：运动7周组大鼠下丘脑、垂体GnRHR mRNA表达及血清E2、P水平均显著降低（P〈0．05—0，01）；运动9周组大鼠下丘脑、垂体、卵巢GnRHR mRNA表达及血清E2、P水平均显著低于同期对照组（P〈0．05-0，01）；恢复2期组大鼠下丘脑、垂体GnRHR mRNA表达，血清岛及P水平仍低于同期对照组（P〈0．05）；恢复3期组大鼠岛、恢复4期组大鼠P水平及各运动及恢复组大鼠子宫GnRHR mRNA，与同期对照组相比均无显著性差异（P〉0．05）。结果提示：递增负荷运动大鼠HPO轴各环节GnRHR mRNA表达的变化与较低浓度的血清性腺类固醇水平，特别与E2水平密切相关，其表达水平的降低可能是运动性月经失调病理过程的重要一环。

Purpose To explore the change in and the significance of GnRHR gene expression in each segment of HPO axis in rats with exercise - induced estrous cycle dysfunction. Methods GnRHR mRNA expression was detected by reverse transcription - polymerase chain reaction （RT- PCR）, and serum E2 dynamic change was measured by fluid equation competition RIA on week 7 and 9 of training, and the recovery courses of 2nd and 4th estrous cycles. Results Serum P concentration showed significant reduction on week 5 of training, GnRHR mRNA in hypothalamus and pituitary, and serum E2 level markedly decreased on week 7 of training. Ovarian GnRHR mRNA reduced significantly on week 9 in overtrained rats. Uterus GnRHR mRNA was not significantly different in control group. Changes in GnRHR mRNA in each segment of HPO axis continued to the 2nd recovery period, and changes in serum E2 and P levels continued to the 3rd and 4th recovery periods. Conclusion GnRHR mRNA expression level of HPO axis was related to the lower serum steroids concentrations, especially E2 concentration. The lower expression level may be responsible for the exercise - induced menstrual irregularity.