Influence of Testosterone on Template Activity of Prostatic Ribonucleic Acids.

Recent studies (l-3) from this laboratory showed that the rate and extent of amino acid incorporation into protein by rat prostatic ribosomes decreased shortly after castration. This decrease is reversed by administration of testosterone to the orchiectomized animals. It was suggested that the levels of template ribonucleic acid’ associated with prostatic ribosomes are under the control of testicular hormones. This paper describes some experiments on the direct detection and characterization of the template activity of ribonucleic acids extracted from purified nuclei and ribosomes of rat ventral prostate glands. Evidence will be presented to show that prostatic nuclei and ribosomes isolated from testosterone-treated animals are richer in template ribonucleic acids than those obtained from control castrates. It will also be shown that prostatic nuclear ribonucleic acid stimulates amino acid incorporation by prostatic ribosomes from recently castrated rats to a greater extent than that of prostatic ribosomes from testosterone-treated castrates. This finding is in accord with our earlier observations with synthetic polyribonucleotides as template ribonucleic acids (1, 2) and supports the contention that the level of template ribonucleic acid associated with prostatic ribosomes is lowered after withdrawal of testicular hormones.