Studies on the function of reticulo-endothelial system. II. Effects of the R.E.S. blocking with macro-molecular PVP on the lymphoid cell reproduction and the production of serum antibody

Macromolecular PVP was introduced intravenously into rabbits for a long period of 3 months, 10 g of PVP in total, and the observations were carried out to see disturbances in hematopoiesis, lymphopoiesis, and immune reaction with special reference to the histologic changes of marrow, liver, spleen and lymph nodes. The results were as follows: 1. A mild anemia was induced by the PVP injection. RE cells of liver and bone marrow were swollen moderately but otherwise no significant histologic changes were induced in bone marrow and liver. 2. A severe lymphocytopenia resulted: the RE cells of lymph follicles were blocked by PVP, the follicles collapsed into a homogeneous mass with fibrosis and minimized lymphopoietic tissues. These results suggest that RE cells of the so-called germinal centers are important for the reproduction or the differentiation of lymphocytes. 3. Intravenous injection of egg albumin caused the serum antibody formation with a marked proliferation of plasma cells around small vessels in lymph nodes and spleen as in the case of control animal. The data indicate that plasma cells are solely responsible for the serum-antibody formation and plasma cell may differentiate from adventitial cells of small vessels but not from lymphocyte or reticulum cell.