Yabumoto H, Ikoma F, Terada N, Takeyama M, Tsuji M, Matsumoto K
J Steroid Biochem. 1983 Nov;19(5):1623-6. doi: 10.1016/0022-4731(83)90380-1.
We have reported [1,2] in immature golden hamster testis that 5 beta-reductase is localized in the seminiferous tubules, while 5a-reductase is present in the interstitial tissue and that the 17 beta-ol-dehydrogenase activity is found predominantly in the seminiferous tubules. In the present study, we show the intratubular localization of these enzymes. The left testis of golden hamster was irradiated with 2000R or 8000R of X-rays at 22 days of age. The hamsters were killed at 28 days of age. Homogenates of the left irradiated and right intact testes were incubated with [14C]-4-androstone-3,17-dione and NADPH, and enzyme activity was estimated. Both testes were also examined histologically. The X-irradiation of the testis resulted in an almost complete disappearance of germ cells with a significant decrease in testis weight, but the interstitial tissue and tubular nongerm cells including Sertoli cells remained almost unchanged. However, the activities of 5 beta-reductase and 17 beta-ol-dehydrogenase expressed as nmol formed/testis/h did not decrease at all. These results show that 5 beta-reductase is localized in the tubular nongerm cells including the Sertoli cells and 17 beta-ol-dehydrogenase is present in the tubular nongerm cells and interstitial tissue in immature golden hamster testis.
我们曾报道过[1,2]，在未成熟的金黄地鼠睾丸中，5β-还原酶定位于生精小管，而5α-还原酶存在于间质组织中，且17β-醇脱氢酶活性主要在生精小管中被发现。在本研究中，我们展示了这些酶在小管内的定位情况。在22日龄时，对金黄地鼠的左侧睾丸进行2000R或8000R的X射线照射。在28日龄时处死这些地鼠。将左侧受照射睾丸和右侧完整睾丸的匀浆与[14C]-4-雄甾酮-3,17-二酮及NADPH一起孵育，并估算酶活性。同时对双侧睾丸进行组织学检查。睾丸的X射线照射导致生殖细胞几乎完全消失，睾丸重量显著下降，但间质组织和包括支持细胞在内的小管非生殖细胞几乎保持不变。然而，以nmol生成量/睾丸/小时表示的5β-还原酶和17β-醇脱氢酶活性根本没有降低。这些结果表明，在未成熟的金黄地鼠睾丸中，5β-还原酶定位于包括支持细胞在内的小管非生殖细胞中，而17β-醇脱氢酶存在于小管非生殖细胞和间质组织中。
