ABO blood group antigens on the membrane of human spermatozoa were investigated with the peroxidase-labelled antibody test. Spermatozoa from 0 secretor were incubated with saliva or seminal plasma of A and B secretors, but the specific peroxidase staining was negative. This result indicates that blood group antigens on human spermatozoa originate from spermatozoon itself, but not from seminal plasma. ABO blood group antigens ; human spermatozoa ; peroxidase-labelled antibody test Yamakami (1926) reported that spermatozoa have a specific inhibiting action on the human isoagglutinin, and in the same year Landsteiner and Levine (1926) demonstrated the presence of A and B blood group antigens on human spermatozoa using the inhibition technique. Thereafter, several investigators obtained similar results with various methods. Levine and Celano (1961), using the absorption-elution method, re-confirmed these results with spermatozoa from both secretor and non-secretor in an attempt to detect D (Rho) antigen in sperm cells. Shahani and Southam (1962), using the fluorescent antisera, supported the presence of blood group antigens on human spermatozoa. Recently, Inoue and Okada (1982, 1983) demonstrated ABO blood group antigens on the membrane of human spermatozoa using both enzyme and ferritin-labelled antibody techniques. However, there still remains a question whether ABO blood group antigens on the membrane of spermatozoa originate from seminal plasma or not. The present study deals with the origin of ABO antigens on human spermatozoa.
MATERIALS and METHODSPreparation of samples. Semen samples were obtained from 13 donors of known blood groups (A secretor 7, B secretor 3, B non-secretor 1, AB secretor 1, and 0 secretor 1), and kept frozen at -40°C until use. One ml of the semen was washed twelve times in 10 ml of 0.01 M phosphate buffered saline (PBS), adjusted to pH 7.2, by centrifugation at 3,000 rpm for 10 min and the deposit was used as washed spermatozoa. The supernatant of twelfth washing was confirmed not to include water-soluble antigens, using either hemagglutination inhibition test or enzyme-labelled antibody test, the latter being performed by the method