Tenover J S, Bremner W J
Department of Medicine, University of Washington School of Medicine, Seattle.
J Gerontol. 1991 Sep;46(5):M181-4. doi: 10.1093/geronj/46.5.m181.
Serum testosterone (T) levels and inhibin levels decline with normal male aging. In addition, in young men, serum T levels demonstrate a circadian variation that is blunted or lost with normal aging. The purpose of this study was to determine whether serum immunoreactive inhibin levels also demonstrate a circadian variation in young men and if normal aging has an effect on the 24 hr serum inhibin pattern. Hourly blood samples were obtained for 24 hr from 7 young (age 25-35 yr) and 7 elderly (age 65-72 yr) healthy men. Serum inhibin and testosterone levels were measured by RIA. Similar to T, serum inhibin levels demonstrated a circadian pattern in young men. Elderly men also demonstrated a circadian rhythm in serum inhibin, with an average amplitude that was not significantly different from that found in young men, despite the fact that the average 24-hr inhibin level in the elderly men was significantly lower than in the young men. These results demonstrate that immunoreactive inhibin, like T, displays a circadian rhythm in the serum of adult men and the inhibin biorhythm is maintained in elderly men.
血清睾酮（T）水平和抑制素水平会随着男性正常衰老而下降。此外，在年轻男性中，血清T水平呈现昼夜变化，而这种变化在正常衰老过程中会减弱或消失。本研究的目的是确定血清免疫反应性抑制素水平在年轻男性中是否也呈现昼夜变化，以及正常衰老是否会对24小时血清抑制素模式产生影响。从7名年轻（25 - 35岁）和7名年长（65 - 72岁）的健康男性中，每小时采集一次血样，共采集24小时。采用放射免疫分析法测定血清抑制素和睾酮水平。与睾酮相似，年轻男性血清抑制素水平呈现昼夜模式。年长男性血清抑制素也呈现昼夜节律，尽管年长男性的平均24小时抑制素水平显著低于年轻男性，但其平均幅度与年轻男性相比无显著差异。这些结果表明，免疫反应性抑制素与睾酮一样，在成年男性血清中呈现昼夜节律，且年长男性的抑制素生物节律得以维持。
