| Objective. The present study was performed to (1) identify the characteristic of expression TNF-a in rats with sepsis induced by cecal ligation and puncture (CLP); (2) investigate the effect of Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway on expression of tumor necrosis factor (TNF)-a in septic rats (3) clarify the role of TNF-a in the pathogenesis of CLP-induced sepsis and subsequent multiple organ dysfunction syndrome (MODS).Material and methods: 140 male Wistar rats were randomly divided into six groups as follows: (1) normal control group (n=10); (2) sham operation group (n=10); (3) CLP group (n=60): being further divided respectively into 0.5h, 2h, 6h, 12h, 24h and 48h subgroups post-CLP; (4) AG490 treatment group (n=24): subcutaneous injection of AG490 at a dose of 8.0mg/kg at 20mins prior to CLP, being further divided respectively into 2h, 6h, 24h and 48h post-CLP subgroups; (5) RPM treatment group (n=24): subcutaneousinjection of RPM at a dose of 0.4mg/kg at 20mins prior to CLP, being further divided respectively into 2h, 6h, 24h, 48h post-CLP subgroups; (6)DMSO treatment group (n=12): subcutaneous injection of DMSO at a dose of 4.0mg/kg at 20mins before CLP, being further divided respectively into 2h and 24h post- sham operation subgroups; At serial time points in each group, animals were sacrificed, and tissue samples from liver, lungs were harvested. TNF-a mRNA expression was semi-quantitative determined by the reverse transcription polymerase chain reaction (RT-PCR) taking GAPDH as an internal standard. Protein levels of tissues TNF-a were determined by enzyme-linked immunosorbent assay (ELISA). The major organ functional indices-serum AST, ALT, BUN and Cr contents, were measured with automatic biochemistry analyzer.Results: 1. The kinetic changes in TNF-a expression in CLP rats TNF-a mRNA expression could be detected in livers and lungs in normal controls, and it did not markedly elevate in sham group. Compared with sham group, TNF-a mRNA in hepatic and pulmonary tissues significantly increased at 0.5h following CLP, peaked at 2h, fell towards to some extent at 24h, and increased markedly again at 48h. It increased ra pidly in lungs with a peak value at 2h, and tended to near normal range at 48h. Meanwhile, the expressive feature of protein of TNF-a in hepatic and pulmonary tissues either following CLP were similar to that of TNF-a mRNA 2. The effect ofpretreatment with AG490 or RPM on TNF-a expression Compared with corresponding time points in CLP group, treatment with AG490 or RPM could significantly inhibit the expression of TNF-a mRNA and protein in septic hepatic and pulmonary tissue induced with CLP at almost all time points. 3. The changes in serum biochemical indices reflecting hepatic and renal function. (1) Serum ALT concentrations were statistically elevated only at 24h after CLP. AST concentrations began to increase significantly from 6h following CLP, peaking at 24h, and keeping at high levels until 48n. BUN contents were statisticallyhigher in CLP group than that in normal controls at 6, 24 and 48h, and Cr contents were much higher compared to normal controls only at 24h after CLP. (2) The effect of AG490 pretreatment on serum biochemical parameters Compared with CLP group, serum ALT and AST levels significantly decreased in AG490-treated group at 24h, and 24 as well as 48h after CLP, respectively. Similarly, both serum BUN and Cr levels significantly decreased at 24h after CLP. (3) The effect of RPM pretreatment on serum biochemical indices Compared with corresponding time points of CLP group, serum ALT and AST levels in RPM-treated group significantly decreased at 24,48h, and 48h after CLP, respectively. Levels of serum of BUN and Cr significantly decreased at 24 or 48h after sepsis. 4. The changes in pulmonary MPO activity and the effect of pretreatment with AG490 and RPM on it Pulmonary MPO activity significantly elevated at 2h Mowing CLP, peaking in 24h, and keeping at relatively high levels at 48h. It was markedly lower in both A...
|
PDF Full Text Request