Kaler L W, Gliessman P, Craven J, Hill J, Critchlow V
Endocrinology. 1986 Sep;119(3):1281-4. doi: 10.1210/endo-119-3-1281.
Enhanced nocturnal release of GH is decreased with aging in man, a change that may implicate GH in a general decline in anabolic metabolism associated with aging. The aim of this study was to determine whether nonhuman primates experience an age-related reduction in plasma GH levels by comparing the 24-h patterns of GH secretion in unrestrained young and aged male rhesus monkeys. Six young (8 yr old) and six aged (22+ yr old) intact rhesus males were fitted with indwelling jugular catheters, cranial platforms, and stainless steel cable tethers. Catheters passed from a swivel device at the top of each cage through a wall to an adjoining room. On four occasions, 1.0-ml blood samples were obtained from each male every 20 min for 24 h for plasma GH RIA. Plasma GH data were analyzed by the PULSAR program to detect hormone peaks. Mean 24-h plasma GH was less (P less than 0.0005) in aged males [0.84 +/- 0.04 ng/ml (+/-SEM)] than in young males (1.37 +/- 0.09 ng/ml). Likewise, the amplitudes of GH pulses were less (P less than 0.001) in aged males than in young males. Although no circadian pattern of GH concentrations was apparent in either age group, young males displayed more (P less than 0.05) nocturnal GH pulses (5.73 +/- 0.41 pulses/12 h) than those occurring during lights-on (3.09 +/- 0.32 pulses/12 h). The numbers of GH pulses in aged males (4.00 +/- 0.63 pulses/12 h) were similar to those in young males during lights-on, but aged males showed fewer (P less than 0.05) nocturnal GH pulses (4.27 +/- 0.47 pulses/12 h) than did young males. The duration of GH pulses in aged males (53.6 +/- 5.0 min) was similar to that in young males (50.6 +/- 5.0 min) during lights-off. Young males showed an extended (P less than 0.001) GH pulse duration (88.8 +/- 8.8 min) during lights-on that was not evident in aged males (66.2 +/- 5.4 min). These data demonstrate that unrestrained young rhesus males experience an enhanced nocturnal release of GH in terms of pulse frequency, and as in humans, this enhanced nocturnal release of GH is diminished with age. In addition, rhesus males experience, as do humans, a reduction in circulating GH levels as a function of age.
随着年龄增长，男性夜间生长激素（GH）分泌增强的现象会减弱，这种变化可能表明GH与衰老相关的合成代谢普遍下降有关。本研究的目的是通过比较自由活动的年轻和老年雄性恒河猴24小时的GH分泌模式，来确定非人灵长类动物是否会出现与年龄相关的血浆GH水平降低。六只年轻（8岁）和六只老年（22岁以上）未阉割的雄性恒河猴被植入颈内导管、颅骨平台和不锈钢缆绳系链。导管从每个笼子顶部的旋转装置穿过墙壁连接到相邻房间。在四次实验中，每只雄性猴子每20分钟采集1.0毫升血液样本，共采集24小时，用于血浆GH放射免疫分析（RIA）。血浆GH数据通过PULSAR程序进行分析以检测激素峰值。老年雄性猴子的24小时平均血浆GH水平[0.84±0.04纳克/毫升（±标准误）]低于年轻雄性猴子（1.37±0.09纳克/毫升）（P＜0.0005）。同样，老年雄性猴子GH脉冲的幅度也低于年轻雄性猴子（P＜0.001）。尽管在两个年龄组中均未观察到明显的GH浓度昼夜节律模式，但年轻雄性猴子夜间的GH脉冲次数（5.73±0.41次脉冲/12小时）多于光照期间（3.09±0.32次脉冲/12小时）（P＜0.05）。老年雄性猴子的GH脉冲次数（4.00±0.63次脉冲/12小时）与年轻雄性猴子光照期间的次数相似，但老年雄性猴子夜间的GH脉冲次数（4.27±0.47次脉冲/12小时）少于年轻雄性猴子（P＜0.05）。老年雄性猴子GH脉冲的持续时间（53.6±5.0分钟）与年轻雄性猴子熄灯期间的持续时间（50.6±5.0分钟）相似。年轻雄性猴子在光照期间的GH脉冲持续时间延长（P＜0.001）（88.8±8.8分钟），而老年雄性猴子则不明显（66.2±5.4分钟）。这些数据表明，自由活动的年轻雄性恒河猴在脉冲频率方面夜间GH分泌增强，并且与人类一样，这种夜间GH分泌增强会随着年龄增长而减弱。此外，与人类一样，雄性恒河猴的循环GH水平也会随着年龄增长而降低。
