Resveratrol ameliorates intestinal barrier injury in rats with hemorrhagic shock through superoxide dismutase 2 activation / 中国中西医结合急救杂志

ABSTRACT

Objective To explore the protective effect of resveratrol (RSV) on intestine barrier injury induced by hemorrhagic shock and its mechanism in rats.Methods According to random number table method,sixty-four SPF grade male Sprague-Dawley (SD) rats were divided into four groupsSham operation group (only the catheters were indwelled in arterial and venous passages after anesthesia),hemorrhagic shock model group (model group,the catheters were indwelled in arterial and venous passages after anesthesia,and 0.3 mL solvent was administrated after hemorrhagic shock),RSV group (the catheters were indwelled in arterial and venous passages after anesthesia,15 mg/kg RSV was administered after hemorrhagic shock),superoxide dismutase 2 (SOD2) specific inhibitor,2-Methoxyoestradiol (2-ME) group (on the basic treatment of RSV group,0.1 mmol/L 2-ME was administered).The hemorrhagic shock model was reproduced by femoral artery bleeding.After drug administration,all rats were divided into two parts.One part was used for observations on 24-hour survival rate and survival time,while in the other part,2 hours after the hemorrhagic shock,the blood was collected for determination of the content of serum D-lactic acid,and afterward the rats were executed to obtain small intestine tissues for the examination of histopathological changes and Chiu's score.Moreover,differences of expression levels of tight junction proteins (Occludin,Claudin,ZO-1) of small intestine tissue and the oxidative stress related indexes SOD2 activity and reduced glutathione (GSH),oxidized glutathione (GSSH),malonaldehyde (MDA) contents were compared among the groups.Results Compared with the sham group,the model group demonstrated decreased survival rate,SOD2 activity,GSH content,GSH/GSSH ratio,reduced survival time,significantly increased serum D-lactic acid activity,Chiu's score and MDA content,and decreased expressions of tight junction proteins in small intestine tissue.Compared with model group,the RSV group showed significant increased survival rate [75.0％ (6/8) vs.37.5％ (3/8)] and prolonged survival time (hours21.0±4.3 vs.10.4±5.8,P ＜ 0.05),significantly decreased serum D-lactic acid (μg/L380.18 ± 70.59 vs.500.88 ± 97.53) and Chiu's score (1.75 ± 0.71 vs.4.00± 0.53) in small intestine (both P ＜ 0.05),obviously increased expressions of tight junction proteins,SOD2 activity,GSH and GSH/GSSG [Occludin (gray value)0.89 ± 0.10 vs.0.43 ± 0.77,Claudin (gray value)0.78±0.06 vs.0.33 ± 0.05,ZO-1 (gray value)0.83 ± 0.06 vs.0.34 ± 0.07,all P ＜ 0.05],and the elevated SOD2 activity (kU/L0.85 ± 0.12 vs.0.51 ± 0.11,P ＜ 0.05],as well as increased GSH content and GSH/GSSG ratio [GSH (μmol/L)7.25±1.01 vs.3.86±0.54,GSH/GSSG6.39± 1.14 vs.1.56±0.25,both P ＜ 0.05] in the small intestine,and markedly reduced MDA content (ng/g5.00± 1.31 vs.8.63±0.92,P ＜ 0.05).Compared with RSV group,the 2-ME group demonstrated significantly decreased survival rate [50.0％ (4/8) vs.75.0％ (6/8)] and further shorter survival time (hours12.2 ± 5.7 vs.21.0±4.3),increased serum D-lactic acid (μg/L463.88 ± 60.16 vs.380.18 ± 70.59),obviously elevated Chiu's score (3.13 ± 0.99 vs.1.75±0.71,P ＜ 0.05),decreased expressions of tight junction proteins [Occludin (gray value)0.55±0.04 vs.0.89±0.10,Claudin (gray value)0.38±0.05 vs.0.78±0.06,ZO-1 (gray value)0.41±0.04 vs.0.83±0.06,all P ＜ 0.05];moreover,the activity of SOD2,GSH content,GSH/GSSG ratio were greatly reduced [SOD2 activity (kU/L)0.58 ± 0.13 vs.0.85 ± 0.12,GSH (μmol/L)4.49 ± 0.52 vs.7.25 ± 1.01,GSH/GSSG1.57 ± 0.39 vs.6.39 ± 1.14,all P ＜ 0.05],and increased MDA content (ng/g6.25 ± 1.04 vs.5.00 ± 1.31,P ＜ 0.05).The small intestine tissue was basically normal in Sham group,and no significant pathological changes were seen;in the model group,the small intestine epithelial mierovilli were collapsed and the mucosal barrier was destroyed obviously;in the RSV group the damages of small intestine microvilli and barrier were markedly alleviated;in 2-ME group the pathological changes were more evident compared with those in the RSV group.Conclusion RSV can improve intestinal barrier injury following hemorrhagic shock in rats;its mechanism may be related to SOD2 activation.