Presence of a sperm agglutinating factor in the normal serum of rabbits against homologous spermatozoa

While determining the presence of erythrocytic antigens on rabbit spermatozoa, it was consistently found that the normal heat-inactivated serum of individual rabbits agglutinated their own spermatozoa (Padma, 1972a). Matousek (1964) also found similar spermagglutinins in the normal sera of bulls, rams and boars against homologous spermatozoa. Edwards (1960) and Weil & Finkler (1959) reported the complement-fixing activity of normal rabbit serum with homo-logous spermatozoa. Chang (1947) showed that a spermicidal factor which was thermolabile and unstable existed in the fresh sera of rabbits, guinea-pigs, rats, bulls and human beings. Freeze drying and subsequent reconstitution des-troyed the factor. Smith (1949) found that normal human and goat sera caused tail agglutination of rabbit spermatozoa. She also reported that head agglutina-tion of spermatozoa occurred with normal rabbit serum but considered this head agglutination to be non-specific and did not study the phenomeno