Chromatographic separation of immunosuppressive factors from seminal plasma from vasectomized boars

Components of boar seminal plasma inhibiting the proliferation of murine and porcine lymphocytes were separated into four peaks by chromatography on Sephacryl S-200. Repeated chromatography of these peaks demonstrated that the substances responsible for inhibition of the blastic transformation of lymphocytes corresponded to components with high molecular weight that during separation were broken down to components with a lower molecular weight; these lower-molecular-weight components also inhibited lymphocyte proliferation. The component with inhibitory activity in peak II (molecular weight 70,000) was manifestly different from the component in peak I (170,000).