The Role And Mechanism Of Glutamine On Intestinal Ischemia-reperfusion Injury Of Rats

Objective：To explore the pathological morphological protective effect of glutamineon intestinal mucosa of ischemia-reperfusion injured rat and to explore itsmolecule mechanism, and observe the influence of different dosingmethod or dosing time on the role of glutamine.Methods：1. Establish rat model of intestinal ischemia-reperfusion injury throughsurgical method.2. We use Enzyme-linked immunosorbent assay (ELISA) to detect changesof TNF-α level in rat blood samples.3. Intestinal specimens embedded in paraffin, sliced, and H&E staining,observe the morphological effect of glutamine on intestinalischemia-reperfusion injury.4.We use RT-PCR and Western-blot method to detect mRNA and proteinexpression of NF-κB and PPAR-γ gene in intestinal tissue samples ofintestinal ischemia-reperfusion injury of rat.Results：1. Rat model of intestinal ischemia: Normal feeding group（NG group）、The tail vein injection of glutamine group (GIG group)、Intragastricglutamine group (GOG group)、The superior mesenteric vein injectionglutamine group（GIOG group）、The intestine injection glutamine group(GIEC group).2. We use ELISA method to detect the level of serum TNF-αof fivegroups of rats(NG、GIG、GOG、GIOG、GIEC), we found that1hour,12hours, the level of serum TNF-αof NG、GIEC group was significantlyhigher than GIG、GOG group, and also higher than GIOG group.3. We use H&E staining method to observe the morphological effect ofglutamine on intestinal ischemia-reperfusion injury in rat. The resultsshowed that in1hour and12hours NG and GIEC groups morphological damage to the intestinal mucosa of rats were very serious. But in1hourand12hours the extent of morphological damage to the intestinal mucosaof GOG、GIG group rats were lighter than NG, GIEC group rats. In1hourand12hours, the extent of morphological damage to the intestinal mucosaof GIOG group rats was more serious than GOG、GIG group rats.4. We use reverse transcription-polymerase chain reaction (RT-PCR) andWestern-blot techniques (Western-blot) to assess mRNA and proteinexpression of NF-κB gene and PPAR-γ gene in rat intestinal mucosaspecimens in each group(NG, GIG, GOG, GIOG, GIEC). mRNA andprotein expression of NF-κB gene and PPAR-γ gene in rat intestinalmucosa specimens is highest in NG, GIEC group. And there is nodifference between the two groups (P>0.05). mRNA and proteinexpression of NF-κB gene and PPAR-γ gene in rat intestinal mucosaspecimens is lowest in GIG, GOG group. Compared with group NG, GIEC,the mRNA and protein expression of NF-κB gene and PPAR-γ gene hassignificant difference.Conclusion：1. For intestinal ischemia-reperfusion injury model in rat, givenglutamine4days in advance, either intravenous injection group, or oralgroup, glutamine can protect intestinal mucosa of rat and can reduce thelevel of serum TNF-α; but given glutamine when intestinal ischemiaexisted, because cells can get much glutamine so soon by intravenousinjection, so it is possible to play a protective role, but given glutaminethrough intestine, because of the existence of ischemia-reperfusioninjury, intestine does not absorb glutamine, so glutamine could notprotect intestinal mucosa and could not reduce the level of serumTNF-α.2. For intestinal ischemia-reperfusion injury model, the role mechanismof glutamine is lowering the activity of TNF-α and increasing theactivity of PPAR-γ to protect intestinal ischemia-reperfusion injury.