ORIGIN OF THE VARIOUS IMMUNOGLOBULINS IN LYMPH FROM THE POPLITEAL LYMPH NODE OF SHEEP BEFORE AND AFTER ANTIGENIC STIMULATION

SummaryVarious immunoglobulins labelled with 131I or 125I were injected into sheep and the distribution of radioactivity between plasma and efferent popliteal lymph followed during the course of an immune response, with a view to determining the nodal contribution of immunoglobulin to efferent lymph. The results showed that up to 60% of the IgM and usually a small amount of the IgG1in efferent lymph were newly synthesized in a lymph node undergoing an immune response.A subcutaneous injection of antigen below the tarsus was often accompanied by early transient increases in the flow and protein concentration of afferent popliteal lymph. In contrast, there were more sustained increases in these parameters in efferent lymph. It is suggested that the higher protein concentration of efferent than afferent lymph prior to antigenic stimulation and the sustained increases in protein concentration of efferent lymph during an immune response are associated with recirculation of lymphocytes through the post-capillary venules in the popliteal lymph node.Australian Journal of Experimental Biology and Medical Science (1974) 52, 887–896; doi:10.1038/icb.1974.88