Anti-acrosin antibodies in sera, colostrum and genital organs of vaccinated ewes: estimation and correlation with fertility.

Three ewes were vaccinated with boar sperm acrosin. Despite the presence of antiacrosin antibodies which crossreact with ram acrosin in the sera of the immunized sheep, no significant reduction in fertility was observed. Incubation of ejaculated or capacitated boar spermatozoa with anti-acrosin serum or IgG did not reduce the halos of digestion in the gelatinolysis test. However, an unexplained decrease of the forward progression and number of lytically active spermatozoa was observed after this treatment. We found antiacrosin antibodies and determined their titers in the sera of the vaccinated ewes, in colostrum and in aqueous extracts of cervix, uterus, oviduct and ovary. No antiacrosin antibodies could be detected in the sera of new born lambs. The immunoglobulins IgA, IgG and IgM were isolated from the sera of the ewes. The acrosin-specific antibodies belonged exclusively to the IgG class. In genital extracts the amount of IgG, IgA and IgM was determined. IgG was found in higher amount in every extract. IgA is present in similar amount only in the cervix, in the other parts only in traces. In all extracts IgM is found in a very low level. The specificity of the antibodies for acrosin was proven by active enzyme staining of the precipitin lines obtained by immunodiffusion.