Effects of prolactin on the dorsolateral lobe of the rat prostate gland.

Intact mature young rats (8 to 10 weeks old) or older rats (16 to 18 weeks old) were used to study the effects of various doses of prolactin on the dorsolateral lobes of the prostate. Prolactin (50 or 150 IU per kg) administered subcutaneously for 5 days in intact mature young rats caused increases in wet weight, protein levels, and nucleic acid levels in the dorsolateral lobes of the prostate. Similar results were obtained when rats were given injections of prolactin for a period of 10 days. When injecting only a 5 IU per kg dose of prolactin, no significant changes were evident in the tissue weight, protein levels, or nucleic acid levels of the prostate gland; however, this same dose produced increases in these biochemical parameters in the dorsolateral lobe of the prostate of older rats.