QUANTIFICATION OF HUMAN SPERMATOGENESIS - GERM-CELL DEGENERATION DURING SPERMATOCYTOGENESIS AND MEIOSIS IN TESTES FROM YOUNGER AND OLDER ADULT MEN
QUANTIFICATION OF HUMAN SPERMATOGENESIS - GERM-CELL DEGENERATION DURING SPERMATOCYTOGENESIS AND MEIOSIS IN TESTES FROM YOUNGER AND OLDER ADULT MEN
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DOI：
10.1095/biolreprod37.3.739
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发表时间：
1987-10-01
影响因子：
3.6
通讯作者：
NEAVES, WB
中科院分区：
文献类型：
--
作者：
JOHNSON, L;NGUYEN, HB;NEAVES, WB
研究了精子发生和减数分裂过程中生殖细胞的退化，以解释与年龄相关的每日精子产量（DSP）下降。对15名年龄在20 - 48岁（平均± 1.5岁）的男性进行了A型暗精原细胞、A型淡精原细胞和B型精原细胞的数量、基于B型精原细胞、早期初级精母细胞和晚期初级精母细胞的每克实质的潜在每日精子产量（PDSP）以及基于早期精子细胞的每克DSP的测定。SEM，33 .+-. 2岁）和15名年龄在52至90岁（65 . ±. 3年）。在死亡（主要是由于创伤或心力衰竭）后15小时内获得的睾丸用戊二醛进行血管灌注。每g薄壁组织中每种细胞类型的数量计算为薄壁组织中细胞核的百分比乘以切片厚度和细胞核直径的校正因子除以该细胞类型的单个细胞核的体积的乘积。老年男性的配对睾丸重量较低（p < 0.01）（33 . ±. 3g）比年轻男性（49 .+-. 3 g）。年轻人和老年人有类似的数量的A-黑暗，A-苍白，B-精原细胞每克实质。基于晚期初级精母细胞的PDSP和基于早期精子细胞的DSP在老年男性中低于年轻男性（p < 0.01）。在年轻男性中，B-精原细胞和晚期初级精母细胞的PDSP相似（p > 0.05），而在精子细胞水平测量的DSP突然低于年轻细胞类型的估计值。老年男性表现出早期和晚期初级精母细胞之间的PDSP减少，DSP在精子细胞水平上进一步减少。因此，年龄相关的差异，在生殖细胞变性，导致较低的精子生产率在老年男性发生在减数分裂前期早期（细线期）初级精母细胞的过渡到晚期（粗线期）初级精母细胞或之间的晚期初级精母细胞本身。
Germ cell degeneration during spermatocytogenesis and meiosis was investigated to explain the age-related decline in daily sperm production (DSP). Numbers of Types A-dark, A-pale, and B-spermatogonia, potential daily sperm production per g parenchyma (PDSP) based on type B-spermatogonia, early primary spermatocytes, and late primary spermatocytes, and DSP per g based on early spermatids were determined in 15 men aged 20 to 48 yr (mean .+-. SEM, 33 .+-. 2 yr) and 15 men aged 52 to 90 yr (65 .+-. 3 yr). Testes obtained within 15 h of death (largely due to trauma or heart failure) were perfused vascularly with glutaraldehyde. The number of each cell type per g parenchyma was calculated as the product of the percentage of nuclei in the parenchyma times a correction factor for section thickness and nuclear diameter divided by the volume of a single nucleus of that cell type. Paired testicular weight was lower (p < 0.01) in older men (33 .+-. 3 g) than in the younger men (49 .+-. 3 g). Younger and older men had similar numbers of A-dark, A-pale, and B-spermatogonia per g parenchyma. PDSP based on late primary spermatocytes and DSP based on early spermatids were lower (p < 0.01) in older men than in younger men. In younger men, PDSP was similar (p > 0.05) between B-spermatogonia and late primary spermatocytes, whereas DSP measured at the spermatid level was abruptly lower than that estimated from younger cell types. Older men showed reduction in PDSP between early and late primary spermatocytes, with further reduction occurring in DSP at the spermatid level. Hence, age-related differences in germ cell degeneration that result in lower rates of sperm production in older men occurred in meiotic prophase during the transition of early (leptotene) primary spermatocytes to late (pachytene) primary spermatocytes or among the late primary spermatocytes themselves.