Kaler L W, Neaves W B
Anat Rec. 1978 Dec;192(4):513-8. doi: 10.1002/ar.1091920405.
Existing evidence suggests that the aging human male experiences a gradual decline in testosterone production, a phenomenon that should be reflected in the Leydig cell population of the testis. It has been proposed that Leydig cells diminish in number with increasing age, but conflicting claims characterize reports of this topic. We have reinvestigated this possibility by histometric analysis of perfused testes from 25 men ranging from 18 to 87 years of age. Average single Leydig cell volume (2,943 +/- 623 micrometer 3, X +/- S.D.) did not change significantly with increasing age (r = 0.24, P greater than 0.2), suggesting that surviving cells remain active. Total testis weight (43.5 +/- 13.9 g) also did not change with age (r = 0.04, P greater than 0.5). However, both total Leydig cell volume and the absolute number of Leydig cells per individual decreased significantly as functions of age (r = -0.71, P less than 0.002, and r = -0.61, P less than 0.005, respectively). Analysis of relationship between these two parameters indicates that the total volume of Leydig cell cytoplasm contained within the human testis is determined by the number of cells present. Our results show that a pair of young adult testes endowed with more than 700 million Leydig cells at 20 years of age may be expected to undergo an attrition rate of approximately 80 million cells per subsequent decade of life. Thus, Leydig cell attrition is an important correlate of declining androgen status in aging men.
现有证据表明，老年男性体内睾酮分泌会逐渐减少，这一现象理应在睾丸间质细胞数量上有所体现。有人提出，随着年龄增长，间质细胞数量会减少，但关于这一话题的报道说法不一。我们通过对25名年龄在18岁至87岁之间男性的灌注睾丸进行组织计量分析，重新研究了这种可能性。单个间质细胞的平均体积（2,943±623立方微米，X±标准差）并未随年龄增长而显著变化（r = 0.24，P>0.2），这表明存活的细胞仍保持活跃。睾丸总重量（43.5±13.9克）也未随年龄改变（r = 0.04，P>0.5）。然而，间质细胞的总体积和个体间质细胞的绝对数量均随年龄显著减少（分别为r = -0.71，P<0.002和r = -0.61，P<0.005）。对这两个参数之间关系的分析表明，人类睾丸中所含间质细胞胞质的总体积由细胞数量决定。我们的研究结果显示，20岁时拥有超过7亿个间质细胞的一对年轻成年睾丸，预计随后每十年会以约8000万个细胞的速率损耗。因此，间质细胞损耗是老年男性雄激素水平下降的一个重要相关因素。
