Journal of steroid biochemistry vol:24 issue:3 pages:661-8
The regulation by androgens of the synthesis of prostatic binding protein (PBP), an abundant secretory protein of the rat ventral prostate, was studied by measuring the rate of incorporation of [3H]leucine into total protein and into PBP by prostatic tissue in vitro. PBP-specific synthesis dropped to 30% of the intact level after 3 days and to 5.5% after 7 days. Administration of androgens to 7 day-castrated rats reversed these changes: 36% of the control value was reached after 3 days of treatment and 70% after 5 days. The mRNAs of PBP were measured under similar conditions by means of dot hybridization, using C1-, C2- and C3-specific cDNA-clones. The 3 mRNAs followed a parallel course. They decreased to about 18% on the third day after castration and to about 2% after 7 days. Androgen treatment of 7-day castrated rats produced a small increase of these levels after 1 day. After 3 days 15% of the intact level was reached. The general similarity of the time course of PBP synthesis and PBP mRNA levels in castrated and androgen treated rats supports a transcriptional regulation mechanism, although there also is some evidence for an influence on protein synthesis in general.