Regulation of prostate 5α-reductase-2 gene expression and prostate weight by dietary fat and caloric intake in the rat

BACKGROUND: High-fat diet is a major risk factor for prostate cancer. 5alpha-reductases are potential targets of dietary fat. METHODS: Male ACI/Seg rats given either a low-fat or a high-fat diet at weaning or adulthood were sacrificed at 2, 4, and 10 weeks after dietary treatment. Prostate 5alpha-reductase mRNAs, plasma androgens, food consumption, prostate, and body weight were determined. RESULTS: Prostate 5alpha-reductase-2 mRNA and plasma dihydrotestosterone levels were elevated at 2 weeks, and prostate weight was increased at 10 weeks in neonatal rats fed the high-fat diet. Animals fed the high-fat diet consumed more calories in the first 4 weeks. 5alpha-reductase-1 mRNA, plasma testosterone, and body weight were not different between the two dietary groups. These dietary effects were not observed in adult rats fed the same diets. CONCLUSION: A high-dietary fat and caloric intake upregulates prostate 5alpha-reductase-2 gene expression, and stimulates prostate growth in neonatal, but not adult rats.