Miyamoto H, Manabe N, Akiyama Y, Watanabe T, Sugimoto M, Sato E
Department of Animal Science, Faculty of Agriculture, Kyoto University, Japan.
Experientia. 1994 Sep 15;50(9):808-11. doi: 10.1007/BF01956460.
The morphometric parameters of spermatogenic cells in a mouse strain prone to accelerated senescence (SAM-P), a novel murine model of spontaneously promoted aging, were compared with those of a SAM resistant strain (SAM-R) after birth until 40 weeks (mean life span of SAM-P). A mixture of gonocytes and spermatogonia were present in the testis in 1-week-old mice, and no gonocytes were observed in 2-week-old mice. At 6 weeks of age, the absolute number of spermatogonia in SAM-P was 27% greater than that in SAM-R, whereas the cell number in 40-week-old SAM-P was 17% less than in SAM-R. Primary spermatocytes were first observed in 3-week-old animals, and the cell numbers in SAM-P at 3, 5 and 6 weeks were 78%, 31% and 25%, respectively, greater than in SAM-R, whereas the cell number in SAM-P at 40 weeks was 30% less than SAM-R. Round spermatids were first observed in all SAM-P at 4 weeks old, but 20% of SAM-R had no spermatids and the rest had only a few. At 5 and 6 weeks old, the absolute numbers of round spermatids in SAM-P were 38% and 41%, respectively, greater than in SAM-R, whereas the cell number in 40-week-old SAM-P was about 34% less than SAM-R. These results indicate that testicular maturation begins at an earlier age in SAM-P than SAM-R. Furthermore, at the age of 40 weeks signs of testicular deterioration are evident in SAM-P mice only.
将易加速衰老的小鼠品系（SAM-P，一种自发促进衰老的新型小鼠模型）生精细胞的形态计量学参数，与抗SAM品系（SAM-R）出生后直至40周龄（SAM-P的平均寿命）的参数进行了比较。1周龄小鼠睾丸中存在生殖母细胞和精原细胞的混合物，2周龄小鼠中未观察到生殖母细胞。6周龄时，SAM-P中精原细胞的绝对数量比SAM-R中的多27%，而40周龄SAM-P中的细胞数量比SAM-R中的少17%。初级精母细胞首次在3周龄动物中观察到，SAM-P在3、5和6周龄时的细胞数量分别比SAM-R中的多78%、31%和25%，而40周龄SAM-P中的细胞数量比SAM-R少30%。圆形精子细胞首次在所有4周龄的SAM-P中观察到，但20%的SAM-R没有精子细胞，其余的只有少数。在5和6周龄时，SAM-P中圆形精子细胞的绝对数量分别比SAM-R中的多38%和41%，而40周龄SAM-P中的细胞数量比SAM-R少约34%。这些结果表明，SAM-P中睾丸成熟开始的年龄比SAM-R早。此外，仅在40周龄时，SAM-P小鼠出现睾丸退化迹象。
