The Action of Phytohemagglutinin in Rabbits

Abstract

Phytohemagglutinin (PRA) has a well established mitogenic and blastogenic action when incubated in vitro with lymphoid cells. The action of this substance was studied in vivo and the histological changes induced by PRA in various organs of the rabbit were compared to those induced by a common antigen (human gamma globulin). It is suggested from the data obtained that PRA does not act as a common antigen. In the PRA treated animals the most striking changes were noted in the spleen. There were marked effects on the white pulp but the most significant histologic features were observed in the red pulp and consisted of intense proliferation of cells of the myeloid-erythroid series. This finding suggests that PRA May have a role in the treatment of diseased states of the bone marrow and lymphoid tissues.