AGE-SPECIFIC AND LOBE-SPECIFIC RESPONSES OF THE BROWN-NORWAY RAT PROSTATE TO ANDROGEN

We examined the effects of age and of increasing concentrations of tes tosterone on the wet weight, protein content, cell number, and cell si ze of the ventral, dorsal, and lateral lobes of the Brown Norway rat p rostate. Young (3 mo of age) and aged (15, 17, and 21 mo of age) rats received implants of increasing sizes of testosterone-filled Silastic capsules for 3 mo. Wet weights of the prostate were the same in untrea ted young (6-mo-old) and aged (18-24-mo-old) rats. Testosterone admini stration resulted in Serum testosterone concentrations ranging from ph ysiologic to superphysiologic. Dose-dependent increases in wet weights and protein contents were seen in the ventral, dorsal, and lateral pr ostatic lobes of both young and aged rats. For each given dose of test osterone, including doses that resulted in serum testosterone concentr ations within the physiologic range, the weights and protein contents of the dorsal and lateral lobes were greater in old (24-mo-old) than i n young (G-mo-old) rats, indicating an effect of age in these lobes. I n contrast, ventral prostate weights and protein contents increased eq uivalently in young and aged rats with increasing testosterone concent ration. DNA content, a measure of cell number, increased significantly in the dorsal and lateral lobes as a function of testosterone dose an d age, but in the ventral lobe did not differ with testosterone dose o r age. Quantitative morphologic analyses showed significant hypertroph y of epithelial cells throughout each of the three lobes in both young and aged rats treated with testosterone. Taken together, these result s indicate that the prostate of Brown Norway rats shows age and lobe-s pecific responses to androgen with respect to wet weight, protein cont ent, cell number, and cell morphology.