Molecular diversity of 11β-HSDs involved in a protection mechanism from the stress-mediated suppression of testosterone production

11β-羟基类固醇脱氢酶（11β-HSD）同工酶（1型和2型）催化生理活性GC和非活性形式的相互转化。这些同工酶的存在下，确定在新生猪睾丸和睾丸间质细胞纯化的RT-PCR，蛋白质印迹和免疫组织化学染色。在整个睾丸中，与1型相比，2型表达水平更高。接下来，在完整的Leydig细胞GC代谢的方向进行了检查，只有从皮质醇到可的松的氧化检测。使用微粒体酶制剂从Leydig细胞，2型表现出强大的氧化活性，活性高于氧化活性催化的1型同工酶。此外，我们还采用实时荧光定量RT-PCR技术对11种β-HSD同工酶mRNA在多种人体组织中的表达进行了全面的检测。本研究结果表明，11β-HSD 1型和11 β-HSD 2型在睾丸Leydig细胞皮质醇失活中均起重要作用，并参与保护睾丸Leydig细胞中糖皮质激素介导的睾酮生成抑制。

11β-Hydroxysteroid dehydrogenase (11β-HSD) isozyme (type 1 and type 2) catalyze the interconversion of physiologically active GC and inactive forms. The presence of these isozymes was determined in neonatal pig testis and Leydig cells purified from testes by RT-PCR, Western blotting, and immunohistochemical staining. In the entire testis, a higher level of type 2 was expressed compared to type 1. Next, the direction of GC metabolism in intact Leydig cells was examined, and only oxidation from cortisol to cortisone was detected. Using a microsomal enzyme preparation from Leydig cells, type 2 exhibited potent oxidation activity, and the activity was higher than the oxidation activity catalyzed by the type 1 isozyme. Furthermore, we performed comprehensive determination of the expression of 11β-HSD isozymes mRNA by real-time RT-PCR in wide range of human tissues. The results of the present study using testis strongly suggest that not only 11β-HSD type 1 but also type 2 plays important roles in cortisol inactivation in Leydig cells of the testis, and is involved in the protection of glucocorticoid -mediated suppression of testosterone production in Leydig cells of the testis.