PURPOSE: A crucial event in the acute regulation of steroidogenesis by tropic hormone is the delivery of cholesterol from cytosol into the mitochondrial inner membrane where it is converted to pregnenolone by the cytochrome P45O cholesterol side chain cleavage enzyme. Recently, it has been observed that the acute production of steroid hormone depends on a rapidly synthesized, cycloheximide sensitive and highly labile protein that appeared in response to tropic hormone. This protein was named as Steroidogenic Acute Regulatory(StAR) protein. The purpose of this experiment was to detect the StAR protein in human testicular tissue. MATERIALS AND METHODS: Human testicular tissues were obtained during the surgery in patients with cryptorchidism, infertility, and prostate cancer Northern blotting hyridization and RT-PCR were performed to detect the StAR mRNA in human testicular tissues. In addition, immunohistochemical staining was performed to test the presence of the StAR protein in human testicular tissues. RESULTS: The StAR mRNA was detected as a weak band in prostate cancer and infertility patients, but not detected in cryptorchidism patients by Northern blotting hybridization. In RT-PCR of human testicular tissues for StAR mRNA, RT-PCR products(about 2000p) were shown to have in cryptorchidism, infertility, and prostate cancer patients. In immunohistochemical staining of human StAR protein, immunoreactivity of human StAR protein was positive in the interstitial tissues of human testis. CONCLUSIONS: The StAR protein that plays a key role in the steroidogenesis was detected in human testicular tissues and this protein will be effective in pathogenesis and treatment of the diseases that are associated with steroid hormones.
Blotting, Northern ; Cholesterol ; Cholesterol Side-Chain Cleavage Enzyme ; Cryptorchidism ; Cycloheximide ; Cytochromes ; Cytosol ; Humans* ; Infertility ; Male ; Membranes ; Pregnenolone ; Prostatic Neoplasms ; RNA, Messenger ; Testis