EFFECT OF DEHYDROEPIANDROSTERONE (DHEA) ON INTESTINAL MUCOSAL IMMUNITY IN YOUNG-ADULT AND AGING RATS

The present study assesses the effectiveness of oral DHEA on the intes tinal mucosal immune response in aging rats. Young adult (6 months) an d aging (21 months) female rats received powdered rat chow with or wit hout 0.2% DHEA for 23 days. The animals were immunized intraduodenally with either cholera toxin (CTx) or vehicle alone and boosted two week s later. Seven days after boosting, serum, bile, small intestinal tiss ue, and liver were collected for analysis. Anti-CTx IgA antibody titer s were measured in serum and bile and the concentration of anti-CTx an tibody containing cells (ACCs) in the small intestinal lamina propria and liver were determined by quantitative immunohistochemistry. Interg roup comparisons indicated that there was only one significant differe nce in serum and none in bile anti-CTx IgA titers between CTx-immunize d animals fed DHEA or the diet alone. Immunohistochemical analysis det ermined that the density and distribution patterns of ACCs within the lamina propria were unaffected by DHEA. Both DHEA-treated and control young immunized animals exhibited similar numbers of ACCs. Only 40% of the aging rats responded to intraduodenal immunization with CTx, as d etermined by the presence of ACCs in the intestine, regardless of the presence or absence of DHEA in the diet. These data suggest that DHEA in the diet does not enhance the intestinal mucosal immune response to intraduodenal CTx in either young adult or aging rats. (C) 1998 Elsev ier Science Inc.