The influence of the lymph node on the protein concentration of efferent lymph leaving the node.

Abstract

The contribution of lymph formed within a lymph node to the total protein output in lymph leaving the node was studied. The lymphatic duct leaving the popliteal lymph node was cannulated and the protein and lymphocyte output in efferent lymph determined. The afferent lymph flow to the popliteal node was then diverted and lymph formed only within the the lymph node collected from the efferent cannula. The popliteal lymph node formed lymph at the rate of approximately 1 ml/h and might contribute 30-50% of the protein output observed in efferent lymph. The importance of lymph formation within the lymph node varied between nodes found in different regions of the body. This was due to the different nodes. A positive correlation was found between the protein and lymphocyte concentrations in efferent lymph from the popliteal lymph node in 7 out of 11 sheep and in lymph formed within the popliteal lymph node in 2 of 3 sheep. This relationship might be due to an increased transfer of plasma proteins through the post-capillary venules in the lymph node accompanying the continual traffic of lymphocytes across the wall of these vessels. The protein transfer across the post-capillary venules was not an indiscriminate transfer of plasma per se but a selective transport from the blood plasma compartment based on molecular size.