Silver R I, Wiley E L, Thigpen A E, Guileyardo J M, McConnell J D, Russell D W
Department of Urology, University of Texas Southwestern Medical Center, Dallas.
J Urol. 1994 Aug;152(2 Pt 1):438-42. doi: 10.1016/s0022-5347(17)32758-1.
Isozymes of steroid 5 alpha-reductase (5 alpha-reductase) have crucial roles in androgen physiology by synthesizing the potent hormone dihydrotestosterone. The expression pattern of the 5 alpha-reductase type 2 isozyme was determined in genital and extragenital tissues by developing an immunohistochemical assay using formalin-fixed tissue and affinity purified polyclonal antibodies that specifically recognize this isozyme. Expression was detected in basal epithelial and stromal cells of the normal prostate but not in luminal epithelial cells. Stromal cells of the seminal vesicle also expressed the type 2 isozyme. In contrast, staining was detected in epithelial cells of the epididymis but not in the surrounding stroma. Myofibroblasts in foreskin samples of normal and hypospadiac individuals expressed antigen and were distributed in bands throughout the prepuce, suggesting a clonal origin. In most cells the type 2 isozyme exhibited a perinuclear subcellular distribution. However, in liver hepatocytes the protein was distributed throughout the intracellular membrane compartment.
类固醇5α-还原酶（5α-还原酶）的同工酶通过合成强效激素双氢睾酮在雄激素生理学中发挥关键作用。通过使用福尔马林固定组织和特异性识别该同工酶的亲和纯化多克隆抗体开发免疫组织化学分析方法，确定了2型5α-还原酶同工酶在生殖器和生殖器外组织中的表达模式。在正常前列腺的基底上皮细胞和基质细胞中检测到表达，但在管腔上皮细胞中未检测到。精囊的基质细胞也表达2型同工酶。相比之下，在附睾上皮细胞中检测到染色，但在周围基质中未检测到。正常和尿道下裂个体包皮样本中的肌成纤维细胞表达抗原，并在整个包皮中呈带状分布，提示其克隆起源。在大多数细胞中，2型同工酶表现为核周亚细胞分布。然而，在肝细胞中，该蛋白分布于整个细胞内膜区室。
