Nitta H, Bunick D, Hess R A, Janulis L, Newton S C, Millette C F, Osawa Y, Shizuta Y, Toda K, Bahr J M
Department of Animal Sciences, University of Illinois, Urbana 61801.
Endocrinology. 1993 Mar;132(3):1396-401. doi: 10.1210/endo.132.3.8440194.
Estrogen production within the testis has been a subject of considerable controversy for many years. Several studies have shown that both Sertoli and Leydig cells produce estrogen during different stages of development. Therefore, we have conducted experiments to localize aromatase, a cytochrome P450 enzyme that converts androgen to estrogen, within the testis. First, P450 aromatase (P450arom) was localized in germ cells of the adult mouse testis by immunocytochemistry, using an antiserum generated against purified human placental cytochrome P450arom. In the germinal epithelium, P450arom was located primarily in the Golgi region of round spermatids, throughout the cytoplasm of elongating spermatids, and along the flagella of late spermatids. Second, localization of P450arom within the germinal epithelium was supported by Western blot analysis of isolated germ cells. Third, Northern blot analysis using a mouse P450arom cDNA probe indicated that the mRNA for the mouse P450arom was present in testicular germ cells. Fourth, P450arom activity was measured in germ cells by the 3H2O water assay. Based upon these observations, we conclude that germ cells are a site of estrogen synthesis in the adult mouse testis.
多年来，睾丸内雌激素的产生一直是一个备受争议的话题。多项研究表明，支持细胞和间质细胞在发育的不同阶段都会产生雌激素。因此，我们进行了实验，以在睾丸内定位芳香化酶，这是一种将雄激素转化为雌激素的细胞色素P450酶。首先，通过免疫细胞化学方法，使用针对纯化的人胎盘细胞色素P450芳香化酶产生的抗血清，将P450芳香化酶（P450arom）定位在成年小鼠睾丸的生殖细胞中。在生精上皮中，P450arom主要位于圆形精子细胞的高尔基体区域，延伸精子细胞的整个细胞质中，以及晚期精子细胞的鞭毛上。其次，对分离的生殖细胞进行蛋白质免疫印迹分析，支持了P450arom在生精上皮中的定位。第三，使用小鼠P450arom cDNA探针进行Northern印迹分析表明，小鼠P450arom的mRNA存在于睾丸生殖细胞中。第四，通过3H2O水测定法测量生殖细胞中的P450arom活性。基于这些观察结果，我们得出结论，生殖细胞是成年小鼠睾丸中雌激素合成的场所。
