Studies on the Reactivity of Lymph Node: Effects of Fasting on the Cell Output Throught the Efferent Lymph

The effects of fasting on the cell output through the efferent lymph from the popliteal lymph nodes of adult rabbits were studied along with the nodal changes. The most striking effects of acute fasting is a marked decrease in the cell output through the efferent lymph. This is chiefly due to a reduction in the efferent lymph flow. The cellular content of the efferent lymph remains almost unchaged, although the nodal weight is much reduced by fasting. The reduction in the nodal weight, on the other hand, runs almost paralled to the decrease in the cell output through the efferent lymph. After stimulating the node by the subcutaneous injection of sheep blood into the foot-pad, simulatneously with the initiation of fasting, the cell output through the efferent lymph is increased to a great extent. This is due to the increase not only in the cellular content of efferent lymph but also in the efferent lymph flow. The weight of the node is also much increased as compared with that of the opposite side. The nodal weight rises almost parallel with the increase in cell output, so that the cell output per unit weight of nodal tissue remains almost unchanged even after the stimulation with antigen. The cellular content of the efferent lymph consists almost exclusively of small lympho cytes in normal and fasted rabbits. After the stimulation with antigen, larger pyroninophilic lymphocytes, especially huge immature blast cells (lympogonia or immunoblasts) defenitely appear in the efferent lymph in large numbers even in the fasted rabbits. Based upon these findings, the effects of fasting on the immune cellular proliferation are discussed.