| Summary: | 碩士 === 臺北醫學大學 === 保健營養學系 === 92 === This study investigated the effect of Gln-enriched diets before and Gln-containing total parenteral nutrition (TPN) after sepsis or both on mucosal and systemic immunity in rats with gut-derived sepsis. Male Wistar rats were assigned to the control and 4 experimental groups. The control and groups 1 and 2 were fed a semipurified diet, while groups 3 and 4 had part of the casein replaced with 25% of total nitrogen as Gln. After feeding the diets for 10 d, sepsis was induced by cecal ligation and puncture (CLP), whereas the control group underwent sham operation; at the same time, an internal jugular vein was cannulated. All rats were maintained on TPN for 3 d. The control and groups 1 and 3 were infused with conventional TPN, while groups 2 and 4 were supplemented with Gln, replacing 25% of total nitrogen in the TPN solution. The TPN solutions were isonitrogenous and identical in nutrient composition except for the difference in the amino acid content. There were 5 groups of rats in this study: the control group, Gln not supplemented before or after the sham operation; group 1, Gln not supplemented before or after CLP (-/-); group 2, a semipurified diet given before and Gln-containing TPN after CLP (-/+); group 3, a Gln-enriched diet given before and conventional TPN after CLP (+/-); and group 4, a Gln-enriched diet given before and Gln-containing TPN after CLP (+/+). All rats were sacrificed 3 d after the sham operation or CLP to examine their immune responses. The results demonstrated that compared with group 1, Gln supplementation before or after CLP maintained plasma Gln levels, preserved total T and helper T lymphocytes in whole blood, splenocytes and Peyer’s patches. Also, plasma immunoglobulin A levels and splenic cytokines mRNA expression were increased in these 2 groups. Gln-enriched diets before CLP significantly enhanced peritoneal phagocytic activity, whereas Gln-containing TPN after CLP promoted intestinal immunoglobulin A secretion. Gln supplementation both before and after CLP seemed to have a synergistic effect on all the immune parameters mentioned above. However, Gln had no favorable effects on reducing plasma cytokine concentration, and the effect of Gln on phagocytic cells in the systemic circulation was not obvious in rats with gut-derived sepsis.
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