Age-related changes in the testes and prostate of the Beagle dog

Age-related changes in the histologic morphology of the Beagle dog prostate and testes must be separated from those changes that may result from the testing of experimental compounds. The prostate and testes of healthy age-matched Beagle dogs 3 to 14 yr of age were obtained. Serum to evaluate testosterone levels was also obtained from each dog at the time of euthanasia. Tissue sections from the prostate and testes were examined by light microscopy for both qualitative and quantitative morphologic assessment. A statistically significant increase in prostatic weight with increased age was noted. Significant morphometric findings in the prostate included a decrease in the relative percent of epithelial cells and an increase in the relative lumen size of glandular acini with increased age. The absolute volume of prostate interstitial tissue and inflammation showed a statistically significant increase with age. Stereological analysis of the testes showed a decrease in the relative percent epithelium with increasing age. No distinct age-related trend could be detected in serum testosterone levels. Serum testosterone levels did not correlate with the morphologic age-related changes observed in the testes or prostate. (author)