The effects of splenectomy, mesenteric lymphadenectomy and portacaval shunt on antibody responses to antigens within the small intestine.

The primary and secondary systemic antibody responses to protein antigens introduced into the gut (diphtheria toxoid, lauroylated human serum albumin) were not diminished or enhanced by previous splenectomy, mesenteric lymphadenectomy or portacaval shunt. Immunization with diphtheria toxoid before such operations did not produce significant alterations in the responses. The cells forming antibody were found predominantly in the lamina propria of the small bowel and to a lesser extent in the subcapsular sinuses of the mesenteric lymph nodes when tissues were examined by the fluorescent antibody technique, ten days after the secondary stimulus of intestinal diphtheria toxoid. The experiments show that the responses, stimulated locally by gut absorbed protein are little affected by an altered portal circulation.