Migration patterns of lymphocytes following syngeneic heterotopic small bowel transplantation in rodents.

Adult rats received syngeneic accessory small bowel grafts with venous drainage to either the portal vein (hetero-portal) or the inferior vena cava (hetero-systemic). Lymphoid cell recovery in different lymphoid organs (spleen, pooled peripheral lymph nodes, mesenteric nodes, Peyer's Patches) was evaluated at varying times (days 0-300) post-grafting. While minimal changes were observed for cell recovery in other organ tissues, lymphocyte recovery in Peyer's Patches of both host and graft small intestine of hetero-systemic animals was decreased from 10- to 100-fold with respect to hetero-portal recipients or non-operated controls. These changes were seen throughout the time course of the study. In additional experiments, lymphoid cells from different organs/donors were labelled in vitro with 111In and injected intravenously into normal/transplanted recipients. Recovery of 111In in various organs was assessed at 1 and 6 h postinjection. The major change seen was in the decreased ability of mononuclear cells derived from Peyer's Patches to migrate to small intestinal tissue (host and graft) in hetero-systemic recipients. In addition, Peyer's Patch cells from these animals 'homed' poorly to small intestine in non-operated animals by comparison with cells from normal rats (or hetero-portal donors).