Cardiotoxicity of Forssman antibodies in in vitro perfusion experiments

Guinea pig heart was perfused in vitro by xenogeneic sera. Sera from both Forssman-positive and Forssman-negative animals exerted strong cardiotoxicity. The toxic effect of rabbit sera could be very significantly decreased by absorption or neutralization of the naturally occurring Forssman antibodies, pointing to the significant role played by these antibodies in the "rejection" of a Forssman-positive organ.