Changes in Lymphocyte Phenotypes and Cytokine Production by Surgical Stress in a Rat Small Intestinal Resection Model

Small intestinal resection rats are used widely as a malabsorption model, but the immunological changes are unclear. We examined the changes in systemic and mucosal immune status after a small intestinal resection in rats with a controlled nutritional status. Rats had 60% of their small intestine removed. At 5 days after the surgery, spleen cells and intraepithelial lymphocytes (IEL) were isolated. The phenotypes of spleen cells and IEL, the production patterns of Th1 and Th2 cytokines, and the proinflammatory cytokine levels in the plasma were measured. CD4+ T cells in the blood and spleen were significantly decreased in the Resection group (p<0.05). In contrast, IEL subpopulations were not different between the two groups. Interferon-γ production from the spleen cells was significantly decreased in the Resection group (p<0.05). Interleukin (IL)-4 production was not different between the two groups. Plasma IL-6 concentrations were significantly elevated in the Resection group 6 h after surgery (p<0.05). In conclusions, small intestinal resection in rats suppressed systemic immunity, and this model is useful as a surgical stress model.