Effect of aging on AXC/SSh rat ventral and dorsolateral prostate S-adenosyl-L-methionine decarboxylase and L-ornithine decarboxylase messenger ribonucleic acid content.

Ventral prostate S-adenosyl-L-methionine decarboxylase (AMDC) and L-ornithine decarboxylase (ODC) transcript content decreased 5-fold as males aged from 6 to 26 months. In contrast, dorsolateral prostate AMDC and ODC transcript content in these individuals was age invariant. The differential effect of aging on tissue transcript levels reflected respective 3.5- and 5-fold decreases in ventral prostate total and poly(A)+ RNA content in aging males, whereas dorsolateral prostate RNA levels essentially were age invariant. Testosterone injection of 26-month-old males increased ventral and dorsolateral prostate content of AMDC and ODC transcripts 4- and 2.5-fold, respectively. Changes in ventral prostate ODC transcript levels correlated well with previously reported age- and testosterone-mediated changes in prostate ODC protein content; however, the relation between ventral or dorsolateral prostate AMDC mRNA levels and previously determined AMDC protein content was less stringent. Our observation that ventral prostate ODC transcript content was 7-fold greater than that of dorsolateral prostate was insufficient to account for the established 200-fold difference in ODC activity in these tissues. Our data imply that transcript content is a principal determinant of ventral prostate ODC activity in aging AXC/SSh rats. However, this relationship does not appear to characterize either ventral or dorsolateral prostate AMDC activity or relative ventral and dorsolateral prostate ODC activity and transcript content. The cause of the age-related preferential loss of ventral prostate RNA remains to be evaluated.