ABSTRACT
Objective To investigate the influences of Radix salvia miltiorrhiza (RSM) preconditioning on the expressions of phosphorylated eukaryotic initiation factor 2α (p-eIF-2ot) and caspase12 in hepatic ischemia reperfusion in rats.Methods Eighty Wistar rats were randomly divided into the control group (5 rats),sham operation group (25 rats),ischemia reperfusion (IR) group (25 rats) and RSM pretreated group (25 rats).Rats in the sham operation group,IR group and RSM pretreated group were subdivided into 5 groups at different time intervals (0,3,12,24 and 72 hours).Mter midline laparotomy,all structures in the hepatic portal were clamped for 45 minutes followed by different periods of reperfusion.Rats in the control group did not receive any treatment; rats in the sham operation group only received anatomy of the hepatic portal without clamping; rats in the RSM pretreated group received RSM by intravenous injection 30 minutes before ischemia at a dose of 6 ml/kg.Rats in the sham operation group and the IR group received a dose of normal saline as RSM pretreated group.The protein expressions of p-eIF-2α and caspase12 in the hepatic tissues of each group were detected by the Western blot,and the pathological changes of hepatic tissues in each group were detected by hematoxylin and eosin staining.All data were analyzed using the analysis of variance,LSD test or Games-Howell method.Results The relative expression of p-eIF-2α in the control group was 0.296 ± 0.038,and the relative expressions of p-eIF-2α in the sham operation group at different time points were 0.304 ± 0.048,0.298 ± 0.038,0.272 ± 0.042,0.266 ± 0.076 and 0.296 ± 0.043,with no significant difference between the 2 groups (P ＞ 0.05).The relative expression of p-eIF-2α in the IR group at 0 hour was 0.310 ± 0.034,which had no significant difference compared with the control group and the sham operation group (F =0.15,P ＞0.05).The relative expressions of p-eIF-2α in the IR group at 3,12,24 hours were 0.386 ± 0.021,0.710 ± 0.034,0.474 ± 0.017,which had no significant difference compared with the control group and the sham operation group (F =11.90,211.52,25.15,P ＜ 0.05).The relative expression of p-eIF-2α in the IR group at 72 hours was 0.336 ± 0.043,which was back to the level of the control group and the sham operation group (F =1.57,P ＞ 0.05).The relative expressions of p-eIF-2α in the RSM pretreated group at different time intervals were 0.278 ± 0.044,0.800 ± 0.079,1.056 ± 0.125,0.736 ±0.087 and 0.442 ± 0.047,which were significantly lower than the group at 3,12,24,72 hours (P ＜ 0.05).The relative expression of caspase12 in the control group was 0.983 ± 0.003,and the relative expressions of caspase12 in the sham operation group at different time intervals were 0.974 ± 0.004,0.983 ± 0.005,0.985 ± 0.003,0.981 ± 0.004 and 0.978 ± 0.004,with no significant difference between the 2 groups (P ＞ 0.05).The relative expression of caspase12 in the IR group at 0 hour was increased to 1.018 ± 0.076,while it had no significant difference compared with the control group and the sham operation group (F =1.43,P ＞ 0.05).The relative expressions of caspase12 in the IR group began to rise at 3 hours (2.056 ±0.067),and peaked at the 12 hours (2.804 ± 0.050),still at a relative higher level at 24 hours (1.882 ± 0.037),and began to decrease at 72 hours (1.282 ± 0.066),it had significant difference compared with the control group and the sham operation group (F=1290.69,6490.84,2898.71,103.61,P ＜ 0.05).The relative expressions of caspase12 in the RSM pretreated group at different time intervals were 0.998 ± 0.056,1.442 ± 0.066,1.990 ± 0.068,1.364 ± 0.056and 0.962 ±0.054.The relative expressions of caspase12 in the RSM pretreated group at 3,12,24,72 hours were significantly lower than the IR group (P ＜ 0.05).The results of pathomorphological examination showed that the hepatic lobules were integrated and the nucleuses were large and round in the control group an d the sham operation group; deformation of the hepatic lobule,smaller cell volume,nuclear condensation and necrosis were observed in the IR group; cell swelling and slight spotty necrosis were detected in the RSM pretreated group.Conclusions RSM could protect liver from damages during IR through up-regulating the expression of p-eIF-2α,reducing the apoptosis induced by endoplasmic reticulum stress.
ABSTRACT
Early growth response gene-1 is an immediate early response gene,a transcription factor which includ three zinc finger-like domains.Recentl studies demonstrate that early growth response gene-1 is involved in regulating cell cycle,proliferation and differentiation,and plays a critical role in injuring and repairing.Early growth response gene- 1 induces Target genes,and promotes extracellular environmental signal( such as oxygen deficit,oxidative stress,mechanical injury and cytokine)link with the complex biological responses.Intensive study to early growth respnse gene-1 will contribute to further illustrate the mechanism of the ischemia-reperfusion injury.This article summarizes from protein structure,signal transduction,biological functions and the relationship with ischemia- reperfusion injury.