Adverse effects of endotoxin following massive distal bowel resection

Sepsis is a frequent cause of morbidity following extensive bowel resection. It has been suggested that the lymphoid tissues of the gut may be essential to normal humoral immunity. This study evaluates: (1) the effect of endotoxin on mortality following selective massive bowel resection and jejunoileal bypass; (2) cellular immunity by skin allograft rejection and bypass, and (3) T and B cell lymphocyte subpopulations is mesenteric lymph nodes, intestine and appendix. Endotoxin increased mortality in rats with more distal bowel resection but not following bypass. Skin allograft rejection was similar in each group. Peyer's patches, mesenteric lymph nodes and appendices were evaluated for T & B cell subpopulations. These tissues had a greater percentage of B cells (53% lymph nodes, 63% appendix) with IgM the predominant immunoglobulin. Cellular immunity was not a factor. Lymphoid tissues of the distal bowel and mesentery contain abundant B cells and IgM that may contribute to humoral immunity. Massive bowel resection may increase the risk of morbidity from gram negative sepsis and/or endotoxin presumably due to decreased humoral immunity.