Winters S J, Troen P
J Clin Endocrinol Metab. 1982 Sep;55(3):560-5. doi: 10.1210/jcem-55-3-560.
The influence of aging on episodic LH secretion and the release of LH and FSH after LRH administration was studied in 14 healthy men, aged 65-80 yr. Mean morning serum testosterone levels were reduced by 16% (P less than 0.05) and serum LH and FSH concentrations were increased by nearly 2- and 3-fold, respectively (P less than 0.01), compared to levels in young men. LH secretory episodes were evident and did not differ significantly in either amplitude or frequency from those of young men in spite of the higher mean LH concentrations. The increments in serum LH and FSH levels after LRH and the areas under the response curves were similar in aged and young men. However, the time of the peak LH response was significantly delayed with aging (P less than 0.001), suggesting an alteration in the control of the releasable LH pool. Further, LH levels were slower to fall after the peak in elderly men (P less than 0.01), suggesting prolonged secretion of hormone after LRH stimulation. These changes did not relate to the basal hypersecretion of LH in elderly men, as the responses in young men with primary gonadal failure did not differ from those in healthy young men (P = NS). The possibility that increased LH molecular size leads to its reduced clearance was not supported by the similar Sephadex G-100 elution profiles for LH in both basal and post-LRH sera from young and old men. Our data indicate that Leydig cell function is impaired in healthy elderly men as a result of primary testicular insufficiency. These studies further reveal the presence of an additional hypothalamic-pituitary disorder of gonadotropin secretion associated with the aging process.
在14名年龄在65至80岁的健康男性中，研究了衰老对促黄体生成素（LH）脉冲式分泌以及注射促性腺激素释放激素（LRH）后LH和促卵泡生成素（FSH）释放的影响。与年轻男性相比，老年男性早晨血清睾酮平均水平降低了16%（P<0.05），血清LH和FSH浓度分别升高了近2倍和3倍（P<0.01）。尽管平均LH浓度较高，但LH分泌脉冲明显，其幅度和频率与年轻男性相比无显著差异。老年男性和年轻男性在注射LRH后血清LH和FSH水平的升高以及反应曲线下面积相似。然而，随着年龄增长，LH反应峰值时间显著延迟（P<0.001），提示可释放LH池的调控发生改变。此外，老年男性在峰值后LH水平下降较慢（P<0.01），表明LRH刺激后激素分泌延长。这些变化与老年男性LH基础分泌亢进无关，因为原发性性腺功能衰竭的年轻男性的反应与健康年轻男性无差异（P=无显著性差异）。年轻和老年男性基础及注射LRH后血清中LH在Sephadex G - 100上的洗脱曲线相似，不支持LH分子大小增加导致其清除率降低的可能性。我们的数据表明，由于原发性睾丸功能不全，健康老年男性的睾丸间质细胞功能受损。这些研究进一步揭示了衰老过程中存在一种额外的下丘脑 - 垂体促性腺激素分泌紊乱。
