Expression of Prostatic Glutathione-Peroxidase (GSH-PO) in The Rat Treated With A Combination of Testosterone and 17β-Estradiol

摘要

In order to confirm the relationship between sex hormone administration and glutathione-peroxidase (GSH-PO) in the rat ventral prostate, the levels of GSH-PO mRNA, GSH-PO activity, and lipid peroxide (Thiobarbituric acid: TBA) value in the ventral prostate were investigated. Male Crj: CD (SD) IGS rats were divided into six experimental groups. Group 1 consisted of intact controls. In group 2, rats were sacrificed two days after castration. In groups 3 and 4, rats were subcutaneously administered 1 ing/animal of testosterone daily for three- or seven-day administration two days after castration, respectively. In groups 5 and 6, rats were subcutaneously administered 1 mg/animal of testosterone plus 0.01 mg/animal of 17β-estradiol (E_2) daily for three- or seven-day administration two days after castration, respectively. GSH-PO activity of the ventral prostate homogenate for testosterone or testosterone plus E_2 administration to the castrated rat was increased and the TBA value was remarkably decreased. The prostatic GSH-PO mRNA level was diminished in the castrated rat ventral prostate, but was increased by testosterone or testosterone plus E_2 administration. In particular, the GSH-PO mRNA level of testosterone plus E_2-treated animals was higher than that of testosterone-treated animals. These findings strongly suggest that expression of GSH-PO in the rat ventral prostate is testosterone- or E_2-dependent. We speculate that the transcription of prostatic GSH-PO mRNA was regulated by testosterone or E_2 and de novo synthesis of GSH-PO would thus be regulated at transcription level by testosterone or E_2.