The Expression And Significance Of Endoplasmic Reticulum Stress Chaperone GRP78in Rat Liver Induced By Ischemia-reperfusion Injury

Objectivecompared expression levels of glucose-regulated protein78(GRP78) related withendoplasmic reticulum stress during the liver ischemia-reperfusion in SD rats, toexplore the possible mechanism and effect of endoplasmic reticulum stress in theischemia-reperfusion process.Methods70%of hepatic ischemia model was induced by clamping the portal vein, hepaticartery and bile duct of the left and median.30healthy male SD rats were randomlydivided into3groups: control group (SO), ischemia group (I) and ischemiareperfusion (I/R).According to the reperfusion time I/R group was divided into I/R6hand I/R12h,each group had6rats. The severity of liver damage was determined bymeasuring serum ALT and AST levels using automatic biochemical analyzer; RT-PCRshowed expression levels of GRP78mRNA in liver tissue; histopathologicexaminations using HE staining; Apoptotic levels was detected by TUNEL staining.All data using SPSS17.0software for statistical analysis.Results1. Compared with SO group, in30min I, I/R6h and I/R12h group serum AST werehigher, respectively was51.01±5.29u/L,131.91±1.74u/L and1.74±4.03u/L;Elevation was observed in serum ALT, respectively was97.94±4.42u/L,324.04±3.22u/L and3.22±5.13u/L, this two indicators had statistically significant difference.between groups, I/R12h group was significantly higher than the I/R6h group (P <0.05).2. Expression levels of GRP78mRNA in30min I, I/R6h and I/R12h group werehigher than SO group, respectively was0.76±1.04,2.61±1.48and5.57±2.11.ischemia-reperfusion group raised most(P <0.01), and I/R12h more than I/R6h(P <0.01).3. According to HE staining we observed that in30min I group hepatic tissue becamepale and disorganized under microscope. Hepatic sinusoid was widened obviously.I/R group seen congestion in different degrees, the severity of liver was more than30min I group, hepatic cells occurring punctuated necrosis, I/R12h was obviouslyhigher than I/R6h, and the number of normal liver cells significantly reduced.4.30min I and I/R group occurred hepatocyte apoptosis, Apoptosis index (AI)respectively was (3.22±0.03)%,(20.87±0.71)%and (59.11±1.92)%.I/R groupwas obviously severer than30min I (P <0.01), I/R12h was worst(P <0.05). Conclusions1. endoplasmic reticulum chaperone GRP78expression was upregulated in theprogress of liver ischemia-reperfusion. ischemia-reperfusion injury;2. endoplasmic reticulum stress maybe was one of mechanisms in acute hepaticischemia-reperfusion through GRP78.