LOCALIZATION AND CONCENTRATION OF A NEW BIOACTIVE ACETIC SEMINAL FLUID PROTEIN (ASFP) IN BULLS (BOS-TAURUS)

The concentration of the new bioactive acetic seminal fluid protein (a SFP) was determined in body fluids of bulls. An aSFP-specific radioimm unoassay was elaborated and established for routine measurement. No cr ossreaction of the aSFP antibody was found with other seminal plasma p roteins and known growth factors. The 14 kDa aSFP was detected in secr etions of ampulla and seminal vesicles by immunoblot analysis, but not in testis, epididymis or blood. Large quantities of aSFP were measure d by radioimmunoassay in the fluid from the ampulla (2.6 +/- 0.3 mg ml -1) and seminal vesicles (3.0 +/- 0.4 mg ml-1). Immunohistochemistry t echniques demonstrated that aSFP was localized mainly in the secretory epithelium of ampulla and seminal vesicles. Large amounts of aSFP (4. 0 +/- 0.4 mg ml-1) were present in seminal. plasma of bulls within a r ange of 1-7 mg ml-1, but aSFP could not be found on membranes of sperm atozoa. Concentrations vary considerably among individuals, suggesting that aSFP may have a role in bovine reproduction.