Stimulation of ornithine decarboxylase in the rat prostate by seminal plasma inhibin.

The effect of seminal plasma inhibin on ornithine decarboxylase activity (ODC) in the rat prostate was studied. A single bolus injection of seminal plasma inhibin caused a 3- to 4-fold increase in ODC activity within 2 h whereas testicular ODC was unchanged. The ODC response to seminal plasma inhibin was neutralized by specific antibodies generated against the inhibin preparation. Another peptide, thyroid releasing hormone has no effect on prostatic ODC activity, but it blocked the increase in enzyme activity induced by treatment with seminal plasma inhibin.