A comparison of lymphocyte migration through intestinal lymph nodes, subcutaneous lymph nodes, and chronic inflammatory sites of sheep.

The migration of 51Cr- and 111In-labeled lymphocytes from blood to various lymph compartments was studied in sheep. When lymphocytes were isolated from lymph, radiolabeled, and returned intravenously to the same animal, nonrandom patterns of lymphocyte migration were observed, which depended on the source of the labeled cells. Lymphocytes isolated from intestinal (jejunum, ileum, or ileocecal junction) efferent lymph always produced greater specific activity in the efferent intestinal lymph than in the efferent lymph of subcutaneous (popliteal or prefemoral) lymph nodes. Conversely, lymphocytes isolated from the efferent lymph of subcutaneous lymph nodes produced greater specific activity in the efferent lymph of subcutaneous lymph nodes than in the intestinal efferent lymph. Unit gravity sedimentation of the free-floating lymphocytes in intestinal efferent lymph demonstrated that small, recirculating lymphocytes, but not lymphoblasts, were responsible for the radioactivity recovered in lymph. The most dramatic examples of nonrandom lymphocyte migration were seen when the migration of lymphocytes was compared between the intestinal efferent lymph and through sites of chronic inflammation.