| Abstrakt: |
Total parenteral nutrition TPN decreases intestinal IgA and levels of Th2 cytokines, interleukin IL4, and IL10 within the supernatants of intestinal homogenates. These cytokines are known to stimulate IgA production in vitroby cells of the gutassociated lymphoid tissue GALT. Glutamine GLN supplementation of TPN normalizes GALT mass and cytokine levels. Because intestinal homogenates contain mucosa which itself is a source of cytokines, it was unclear whether cytokines change within the GALT itself. This study investigates dietary effects on IL4 and IL10 cytokine mRNA expression within isolated GALT lamina propria cells after lipopolysaccharide LPS stimulation. Prospective randomized experimental trials were used in this study. Fiftynine mice were randomized to chow, intravenous TPN IVTPN, intragastric TPN IGTPN, complex enteral diet CED, or 2 GLNsupplemented TPN GLNTPN. In experiment 1, animals were fed chow, IVTPN, IGTPN, or CED for 5 days and received intraperitoneal LPS 100 gkg BW, and then were sacrificed 1 h later. Intestine was harvested for GALT lamina propria. Total RNA was extracted from lamina propria cells and cytokine mRNA for IL4, and IL10 was measured by reverse transcriptase polymerase chain reaction. IgA levels of intestinal washing were also measured with ELISA. In experiment 2, mRNA for IL4 and IL10, and intestinal IgA levels were measured in mice fed chow, IVTPN, or GLNTPN as in experiment 1. Both IL4 and IL10 mRNA expression decreased significantly in IVTPN mice compared to chow or CED feeding. IGTPN resulted in IL10 mRNA expression significantly lower than chow or CED but significantly better than IVTPN. GLN preserved IL4 and IL10 mRNA levels, which correlated with intestinal IgA levels. Route and type of nutrition as well as GLN influence message for the Th2 type IgAstimulating cytokines, IL4 and IL10, within the primary site of GALT IgA production, the lamina propria. |
