Effect of shock lymph on the expression of inflammatory mediators in pulmonary micro-vascular endothelial cells of rats

Abstract

To observe the effect of lymph collected during shock on free radical and expressions of nitric oxide (NO), tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) mRNA of pulmonary micro-vascular endothelial cells (PMVECs) of rats in order to explore the mechanisms of damaging effect of lymph collected during shock to the PMVECs. PMVECs were isolated and cultured, and used at passage 3. The model of serious hemorrhagic shock was reproduced by maintaining the arterial blood pressure of rats at 40 mm Hg (1 mm Hg=0.133 kPa) for 90 minutes by exsanguination under aseptic condition. Mesentery lymph and portal vein blood were obtained from both shock rats and normal rats. PMVECs were respectively incubated in them for 6 hours, and at the same time, fetal bovine serum (FBS) and serum-free DMEM were used as culture media for comparison. The expressions of inducible nitric oxide synthase (iNOS), TNF-alpha and IL-6 mRNA were detected by the method of reverse transcription-polymerase chain reaction (RT-PCR), and the content of malondialdehyde (MDA), NO, TNF-alpha and IL-6 in culture supernatants were determined. After the PMVECs was treated by shock lymph at a final concentration of 4% for 6 hours, the expressions of iNOS, TNF-alpha and IL-6 mRNA in PMVECs and the contents of MDA, NO, TNF-alpha and IL-6 in culture supernatant fluids in shock lymph group were significantly increased compared with those of FBS group, normal lymph group, shock plasma group, normal plasma group and DMEM group. At the same time, the expressions of iNOS, TNF-alpha and IL-6 mRNA in PMVECs and the contents of NO in culture supernatant fluid of shock plasma group were significantly increased compared with those of FBS group, normal lymph group, normal plasma group and DMEM group (P<0.05 or P<0.01). The results demonstrate that the shock lymph in final concentration of 4% could enhance the expressions of iNOS, TNF-alpha and IL-6 of PMVECs, reduce the free radical, and as a result, induce damage to PMVECs.