INHIBITION OF PROSTATE DUCTAL MORPHOGENESIS BY RETINOIC ACID

Purpose: To examine the effect of retinoic acid on prostate ductal mor phogenesis. Materials and Methods: Newborn male Balb/C mice were injec ted with 25 mg./kg. all-trans retinoic acid or vehicle alone. Animals were sacrificed at 60 days of age and prostate ductal morphology was q uantitatively assessed by microdissection. Total prostate DNA was quan titated by DPA assay. Results: The greatest effect was seen in the ven tral prostate. Retinoic acid treated animals showed a 20% decrease in mean number of branch-points (p = 0.0006) with a corresponding 13% dec rease in duct tips (p = 0.026). The combined ventral and dorsal prosta te showed an effect with a 12% decrease in ductal branchpoints (p = 0. 048). There was no effect on animal or organ weight and no effect on D NA content within the prostate. There was no difference in the prostat e histology of treated and control animals. Conclusion: Retinoic acid administration in the newborn period inhibits mouse prostate ductal mo rphogenesis. This effect appears independent of an inhibition of overa ll growth.