[Immunorestitutive action of hydrolysates and ultrafiltrates of bovine spleen].

Investigations with different spleen extracts of varied composition and purity have shown immunomodulatory effects. In the present study the in vivo effect of a bovine spleen hydrolysate (Prosplen) on a radiation-induced immunodeficiency model is demonstrated. Intraperitoneal application of 1 mg/g bw hydrolysate 3/times a week caused a highly significant acceleration of the restitution of the humoral and cell-mediated immunoreactivity towards sheep erythrocytes in sublethally (600 cGy) radiated mice: plaque-forming cells in the spleen, hemagglutination, hemolysistiter of the serum, delayed type of hypersensitivity = DTH reaction. The immunoreactivity of the treated groups reached normal levels within 6-8 weeks, whereas in the groups receiving placebo this was observed after 10 weeks at the earliest. Cytofluorometric investigations revealed an accelerated restitution of the B-lymphocyte fraction in the spleen. Mice that was not irradiated showed no effect after treatment with the hydrolysate. Similar results were obtained using an ultrafiltrate of the hydrolysate.