Beta2-microglobulin, carcinoembryonic antigen and prostatic acid phosphatase in split ejaculates and urine voided before and after massage of the prostate.

Analyses of split ejaculates and urine voided before and after prostatic massage have been used to evaluate the origin of beta2-microglobulin (b2m) and carcinoembryonic antigen (CEA) in human semen. CEA and b2m were present in rather high concentrations in all the fractions of the split ejaculates. The urine voided after massage of the prostate also contained increased levels of CEA and beta2-microglobulin. Split ejaculates, selected from the electrophoretic pattern obtained for each fraction, revealed that b2m in seminal plasma originates from the prostate and seminal vesicles in equal amounts. Besides the "free" b2m in seminal plasma, human semen contains a sperm-bound b2m fraction. Carcinoembryonic antigen was found in the highest concentrations in the second fraction of split ejaculates indicating that it originates mainly from the prostate.