ABSTRACT
OBJECTIVE: To study the effect of omega-3 polyunsaturated fatty acids (omega-3 PUFA) on inflammation in lung tissue of rats with severe scald and its mechanism. METHODS: Seventy-two adult SD rats were divided into sham scald group (SS, n = 8), treatment group 1 (T1, n = 32), treatment group 2 (T2, n = 32) according to the random number table. Rats in T1 group and T2 group were inflicted with 30% TBSA full-thickness scald, and then they were respectively injected with 100 g/L omega-3 PUFA (1 mL/kg) and 200 g/L long-chain fatty acid (2 mL/kg) via tail vein within 5 minutes after burn. The above two fatty acids with equivalent calories were continuously injected for 10 days (once a day). On post burn day (PBD) 1, 4, 7, and 10, serum level of TNF-alpha and level of macrophage inflammatory protein 1alpha (MIP-lalpha) in lung homogenate of T1 and T2 groups were detected, the levels of NF-kappaBp65 and macrophage migration inhibitory factor (MIF) in lung tissue of T1 and T2 groups were observed with immunohistochemical staining (recorded as score). Above-mentioned parameters were also determined in SS group. Data were processed with t test. RESULTS: The levels of 4 parameters in T1 and T2 groups on PBD 1, 4, 7, 10 were higher than those in SS group (with t values from 3.411 to 8.782, P values all below 0.01), and those in T1 group on PBD 4, 7, 10 were lower than those in T2 group (with t values from 2. 321 to 2.785, P values all below 0.05). The serum level of TNF-alpha and levels of MIP-1alpha, NF-kappaBp65, and MIF in lung tissue in SS group was respectively (0.96 +/- 0.32) ng/mL, (76 +/- 16) pg/mL, 0.24 +/- 0.03, 1.31 +/- 0.03, and those in T1 and T2 groups all peaked on PBD 7 [(2.43 +/- 0.32) ng/mL, (210 +/- 56) pg/mL, 4.23 +/- 2.15, 4.69 +/- 1.83; (3.15 +/- 0.54) ng/mL, (274 +/- 64) pg/mL, 5.15 +/- 2.31, 5.37 +/- 2.16]. CONCLUSIONS: Omega-3 PUFA can effectively reduce serum level of TNF-alpha and levels of MIP-1alpha, NF-kappaBp65, and MIF in lung tissue of rats with severe scald, showing that it has a protective effect against injury of lung tissue.
Subject(s)
Burns/metabolism , Burns/therapy , Fatty Acids, Omega-3/therapeutic use , Inflammation/metabolism , Lung/metabolism , Animals , Burns/pathology , Chemokine CCL3/metabolism , Female , Intramolecular Oxidoreductases/metabolism , Macrophage Migration-Inhibitory Factors/metabolism , Male , Rats , Rats, Sprague-Dawley , Transcription Factor RelA/metabolism , Tumor Necrosis Factor-alpha/bloodABSTRACT
OBJECTIVE: To investigate the protective effects of enteral immuno-nutrition on intestinal mucosa injury following severe burn. METHODS: Sixty-four Wistar rats with 30% total body surface area (TBSA) full-thickness burn were randomly divided into enteral nutrition (EN, n=32) group and enteral immuno-nutrition (EIN, n=32) group. Another 8 Wistar rats were used as normal control group. The concentration of secretory immunoglobulin A (sIgA) in intestinal mucosa, the blood levels of diamine oxidase (DAO) activity and tumor necrosis factor-alpha (TNF-alpha) were determined, and the expression of TNF-alpha mRNA in intestinal mucosa was determined by reverse transcription polymerase chain reaction (PT-PCR) in control group and on 1st, 4th, 7th, and 10th day postburn in EN and EIN group. RESULTS: Compared with that of before injury, the blood levels of DAO activity, TNF-alpha content, the concentration of sIgA and the expression of TNF-alpha mRNA in intestinal mucosa were significantly increased in both EN and EIN groups (P<0.05 or P<0.01). However, the blood levels DAO activity, TNF-alpha content, the concentration of sIgA on 4th, 7th and 10th postinjury days and the expression of TNF-alpha mRNA in intestinal mucosa on 1st, 4th, 7th and 10th days postinjury in EIN group were significantly lower than those in EN group (P<0.05 or P<0.01). CONCLUSION: EIN can ameliorate the damage of the intestinal mucosa in burned rats compared with EN group. This might be related to an increase in the sIgA level and reduction of the expression of TNF-alpha mRNA in intestinal mucosa.
