Expressions of Sulfated Glycoprotein 2 and pSvr-1 Genes and Involution of Steroid Hormone-Dependent Rat Tissues

Abstract

To further survey the molecular mechanisms underlying the involution of steroid hormone-dependent rat tissues, we undertook experiments to test whether or not any significant correlation between the tissue involution and expressions of rat sulfated glycoprotein 2 (SGP-2) and pSvr-1 genes, which had been initially cloned from the Sertoli cells and the seminal vesicles, respectively, and then identified as androgen repressed messages both in the ventral prostate and in the seminal vesicles, could be observed in steroid hormone-dependent rat tissues. Expressions of these genes were stimulated within 48 h after castration of animals both in the ventral prostate and in the seminal vesicles as reported previously, but not significantly altered by ovariectomy in the uterus. Expressions of these genes in the thymus were significantly repressed by the administration of dexamethasone and/or cycloheximide. Although the roles of expressions of SGP-2 and pSvr-1 genes in steroid hormonedependent tissues remain unclear, their presence might become useful molecular markers of tissue involution not only in androgen-dependent rat tissues but also in glucocorticoid-dependent ones, and also provide excellent model systems for the study of negative regulation mechanism of gene expression by steroid hormones.