[Experimental xenografting in widely divergent species: Interaction of humoral factors in hyperacute xenograft rejection in the rat-dog system (author's transl)].

The purpose of this paper is to test serum factors which are by interaction with cells responsible for the HXAR. Special stress was laid upon the examination of different serum fractions with or without the presence of preformed natural antibodies. Xenohemoperfusion: Rat kidneys were isolated and perfused in vitro with both whole blood resp. serum fractions and various perpheral cells of dogs. Rejection criterion was the diminishing renal blood flow at a constant pressure of the perfusion. Perfusate: Dog serum fractions were isolated by means of carton electrophoresis into the following fractions: Albumin, alpha-1, alpha-2, beta and gamma-globulin. Dog peripheral blood cells were separated into WBC, RBC and platelets by means of centrifugation and washing of EDTA whole blood. The serum fractions were tested for antibodies using hemagglutination and complement fixation techniques. 1. Hemoperfusion with serum fractions leads to a longer perfusion rate and to higher renal blood flow than perfusion with whole dog blood. 2. No preformed natural antibodies were found in the alpha-2 globulin fractions; however, perfusion with alpha-2 globulin fractions produced a rejection phenomenon both in combination with cells and erythrocytes. 3. Perfusion with serum fractions containing preformed natural antibodies produced a rejection only when WBC and thrombocytes were present. These results suggest that HXAR is induced by two different mechanisms: 1. The effect of humoral natural antibodies (found in the beta and gamma globulin fraction) together with peripheral cells. 2. The effect of a non-immunological humoral factor, found in the alpha-2 globulin fraction, leading to destruction of the xenogeneic organ, obviously to a minor degree dependent on interaction with peripheral cells.