Effect of enteral diet supplemented with arginine on anti-inflammatory cytokines after thermal injury in rats

Male Wistar rats weighing about 200g underwent catheter jejunostomy and rec eived scald bums covering 30% of the whole-body surface area. Animals were divided into two groups: a control group (no supplemental arginine, n = 8) and an arginine group (supplemental arginine: 7.7 g/L, n = 8), both of whom received continuously total enteral nutrition for 7 days (250 kcal/kg/day, 1.72 gN/kg/day). The mRNA expression of interleukin-2 (IL-2), IL-10, and t ransforming growth factor-betal (TGF-beta1) in the spleen, thymus, lungs, a nd liver was measured by a semiquantitative reverse transcription-polymeras e chain reaction method. The concentration of the cytokines in plasma and s upernatant of the cultured splenic lymphocytes was determined by enzyme-lin ked immunosorbent assay. The enteral diet supplemented with arginine signif icantly decreased the messenger RNA expression for IL-2 and TGF-beta1 in th e spleen (p < 0.05, p < 0.01), and for IL-2 in the lungs (p < 0.05) in burn ed rats when compared with the control diet. Moreover, the level of IL-2 in the supernatant from the cultured splenic lymphocytes was significantly su ppressed in animals fed the arginine-supplemented diet (p < 0.05). These re sults suggest that dietary arginine supplementation decreases the mRNA expr ession and production of anti-inflammatory cytokines after thermal injury. (C) 2001 Elsevier Science Inc. All rights reserved.