The Protective Effect Of Oral Rehydration Solution Ⅲ On Multiple Organ Dysfunction In Exertional Heatstroke Rats

Objective:To investigate the protective effect of Oral Rehydration Solution III（ORS III）on multiple organ dysfunction in exertional heatstroke（EHS）rats.Methods:51 male SD rats were ramdomly divided into 4 groups:Control（n=13）,EHS（Exertional heatstroke）（n=13）,EHS+Water（n=12）,EHS+ORS（Oral Rehyration solution）（n=13）.All rats received adapative trainning 7 days before the experiment.On the 8^th day,rats from group EHS+Water were injected by gavage with 20ml/kg water.Rats from group EHS+ORS were given the same volume of Oral Rehydration Solution III（ORS III）.The EHS model was built through exercising under hot enviroment.We considered core temperature of 40.5℃as the onset of exertional heatstroke.After 6 hours,the concentrations of serum creatine phosphokinase-MB（CK-MB）,lactate dehydrogenase（LDH）,alanine transaminase（ALT）,aspartate transaminase（AST）,Serum creatinine（SCr）,blood urea nitrogen（BUN）,serum potassium（K⁺）,serum sodium（Na⁺）and serum chloride（Cl^-）were detected by Antomatic Chemical Analyzer.Serum neutrophil gelatinase-associated lipocalin（NGAL）was measured using an NGAL ELISA Kit.Serum intestinal fatty acid-binding protein（I-FABP）were measured by I-FABP ELISA Kit.Light microscopy was used for kidney structural analysis.The data were analyzed using SPSS21.0.For data which followed a normal distribution,values were expressed as mean±SD.Skewed data were expressed as median（25%–75%）quartiles.Comparisons for parametric data among groups using a one-way analysis of variance（ANOVA）,following LSD multiple comparisons.For non-parametric data,significance levels were from Kruskal–Wallis ANOVA,A value of P<0.05 was considered statistically significant.Results:The LDH level in group EHS rats was higher than group Control（P=0.032）,the concentrations of ALT,AST,Na⁺and Cl^-in group EHS were significantly higher than group Control（P<0.001）,while the concentration of K⁺in group EHS+ORS was lower than group EHS（P=0.002）.NGAL levels in Group EHS were higher than Group Control（P<0.001）.NGAL concentrations in group EHS+Water were no different from Group EHS（P>0.05）,but NGAL levels were significant between Group EHS and Group EHS+ORS（P=0.012）.For the intestinal barrier function assessment,I-FABP level in group EHS was higher than group Control（P<0.01）,the same conclusion was observed between group EHS and group EHS+Water（P<0.05）,as well as group EHS and EHS+ORS（P<0.01）.Renal histopathologies of rats in Group EHS and Group EHS+Water showed flattened lumens filled with eosinophilic materials.The damage was milder in Group EHS+ORS,in which injured tubules showed degeneration of the tubular epithelium and sloughing of the brush border membrane.Conclusions:1、EHS could lead to liver and intestinal barrier dysfunction,as well as ion imbalance.2、Pre-treatment of ORS III could alleviate the intestinal function and ion disorder caused by EHS in rats.It can lower the serum K⁺to some extent.ORS III could alleviate the kidney injury in EHS rats.However,the ORS III failed to protect heart and liver from EHS.