THE EFFECT OF EXOGENOUS TESTOSTERONE ON TOTAL AND FREE PROSTATE-SPECIFIC ANTIGEN LEVELS IN HEALTHY-YOUNG MEN

Purpose: We evaluated the effect of exogenous testosterone administrat ion on serum total and free prostate specific antigen (PSA) in healthy young men. Materials and Methods: Nine volunteers received either 100 , 250 or 500 mg, testosterone by intramuscular injection each week for 15 weeks. Blood was drawn every other week for 28 weeks and at week 4 0. Serum total and free PSA, and total and free testosterone were meas ured and compared to baseline values. Results: Significant elevations in total and free testosterone occurred but no significant change in s erum total and free PSA was detected. Conclusions: Serum PSA is not re sponsive to elevated serum testosterone levels in healthy young men. P SA metabolism in the normal prostate is unclear but our findings may h ave implications for differentiation of pathological conditions of the human prostate.