Immunization with spermatozoal peptide antigens resulting in immuno-suppression of fertility rates in female rats.

Low molecular weight peptides have been isolated from the rat epididyml sperm surface using gel chromatography and preparative thin-layer chromatography. After coupling the partially purified peptides to rat albumin these were injected into female Wistar rats. Immunization with these spermatozoal peptides resulted in significantly reduced fertility rates as determined by the frequency of pregnancies and the number of fetuses per rat. The purification steps revealed that these rat spermatozoal peptides were comparable with peptides isolated form human ejaculated spermatozoa. It is therefore assumed that immunization with these antigens might induce sterility in humans.