Effects of direct peritoneal resuscitation with sodium pyruvate from hemorrhagic shock on intestinal injury in rats

Abstract

Objective To investigate the effects of direct peritoneal resuscitation (DPR) with sodium pyruvate from hemorrhagic shock (HS) on intestinal injury in rats.Methods Fifty SPF male Sprague-Dawley rats,weighing 200-250 g,were used in this study.The animals were anesthetized with 1％ pentobarbital sodium 40 mg/kg,tracheostomized and mechanically ventilated.Femoral artery was cannulated for mean arterial pressure (MAP) monitoring,blood-letting,blood sampling and fluid infusion.HS was induced according to the method described by Wiggers.MAP was maintained at 35-40 mm Hg for 60 min.The animals were then randomly and equally divided into 5 groups:sham operation group (group S) ; conventional resuscitation group (group CR) ; DPR with different fluid groups (DPRt-3 groups).In group CR,at 1 h after HS,the animals were resuscitated with infusion of the blood withdrawn and normal saline (the volume was 2 times volume of blood loss).In DPR1-3 groups,conventional resuscitation was performed,at the same time,1.5 ％ glucose-based peritoneal dialysis solution containing lactate,1.5％ glucose-based peritoneal dialysis solution containing lactate (40.00 mmol/L),and 1.5％ glucosebased peritoneal dialysis solution containing high lactate (80.00 mmol/L) 20 ml were infused intraperitoneally over 30 min,respectively.MAP was recorded before blood letting,at 5,30 and 60 min of HS,and at 5,30,60,90 and 120 min after the end of resuscitation.At 120 min after the end of resuscitation,the lactate level in the arterial blood was measured.The animals were then sacrificed.Small intestinal samples were obtained for determination of malondialdehyde (MDA) content,myeloperoxidase (MPO) activity and tumor necrosis factor-α (TNF-α) expression,and for microscopic examination.The damage to the small intestinal mucosa was assessed and scored.Results Compared with MAP before blood letting,MAP during HS was significantly decreased,and no significant change in MAP was found after resuscitation in CR and DPR1-3 groups (P ＜ 0.05).The lactate level in the arterial blood,MDA content,MPO activity,TNF-α expression and intestinal mucosal damage scores were significantly higher in CR and DPR1-3 groups than in S group (P ＜ 0.05 or 0.01),while lower in DPR1-3 groups than in CR group (P ＜0.01),and in DPR2,3 groups than in DPR1 group (P ＜ 0.05 or 0.01).The lactate level in the arterial blood,MDA content and TNF-α expression were significantly lower in DPR3 group than in DPR2 group (P ＜ 0.05 or 0.01).Conclusion Direct peritoneal resuscitation with sodium pyruvate can reduce the intestinal injury induced by HS and inhibition of lipid peroxidation and inflammatory responses is involved in the mechanism in rats. Key words: Pyruvic acid; Peritoneal dialysis; Resuscitation; Shock, hemorrhagic; Intestines; Reperfusion injury