The Study On The Rats Multiple Organs Damage On Movement Under High Tempreture&Humidity And Its Mechanism

Heatstroke is a high morbidity rate and high mortality medical emergency,dividedinto classic heatstroke disease (classic/the nonexertional heat stroke, CHS) andexertional heatstroke disease (exertional heat stroke, EHS). The former is mainlycaused by the ambient temperature, occur in the elderly, immunocompromised and/or complicated by other diseases; latter is mainly due to the increase in individualstrenuous exercise heat production, heat production is far more than the body coolingcapacity due mostly occurs in young healthy people, such as athletes, soldiers.ObjectiveBuild exertional heat stroke model in rats, observe the experimental rat liverfunction, renal function, blood biochemical indices and related parameters of liverlipid peroxide (MDA, SOD,8-OhdG), SIRS major inflammatory mediators (TNF-α,IL-6) the change of the concentration and hepatocyte mitochondrial membranepotential and common pathological detection for the rat liver, kidney, lung, heart,brain under the different conditions of building,, and then discuss under hightemperature and high humidity environment strenuous exercise for the liver injury andits mechanism, improve the understanding of exertional heat stroke, as well as ourscientific training and combat tolerated under special conditions.Methods1.Through computer control rats wheel running machine and construct theexertional heat stroke model; mechanical preparation of fresh liver cell suspension,and then using the JC-1(5,5’,6,6’-tetrachloro-1,1’,3,3’-tetraethylbenzimidazolcarbocyanine iodide) staining using flow cytometry todetect hepatocyte mitochondria membrane potential changes.2.The morphology and pathological changes of rat liver, kidneys, heart, lungs,brain was observed with hematoxylin and eosin (HE) staining in the control group, theexperiment group1(normal temperature movement group), the experiment group2(high temperature high humidity movement group).and test the alanine aminotransferase (ALT), nmda aminotransferase (AST), alkaline phosphatase (ALP),gamma glutamyl transpeptidase (GGT),urea nitrogen (BUN), creatinine (CRE), andthe concentration of creatine kinase (CK) in rats serum by automatic biochemicalanalyzer.3.Using enzyme-linked immune response to detect the plasma Tumor necrosisfactor α(TNF-α), Interleukin-6(IL-6),8-hydroxy deoxyguanosine (8-OhdG)concentration; explore exertional heat stroke cause liver dysfunction pathologicalinitiating link and its possible mechanism.Consequence1. Running timeExperimental group1, and the experimental group2rats running time to startrunning to exhaustive or the body temperature of the diagnostic criteria of the timeperiod, controlled way was not involved in sports, the experimental group of rats1onaverage to exercise for60±5min, experiment group2rats an average time of15±3min, there is significant difference (p=0.002).2. Liver mitochondrial membrane potential changeThe control group, compared with the experimental group1, P>0.05; control group ascompared with the experimental group2, P <0.05; experimental group1compared tothe experimental group.3. Biochemical results(1)Blood biochemical results①Compared with control group, serum ALT, AST, ALP, LDH, CREA, BUN andCK were significantly elevated in experimental group1and group2, there issignificant difference (P <0.05),②Contrast experiment1and2, serum ALT, AST,ALP, LDH, CREA, BUN and CK were significantly elevated, there is significantdifference,(P <0.05);(2)8-OhdG levelCompared with the control group: liver tissue8-OhdG express elevated inexperiment1and2, there are significant difference（p=0.029）, and the contrastbetween two groups has significant difference,(p=0.042). (3)Plasma levels of inflammatory mediatorsCompared with the control group:①the rats plasma IL-6increased obviously inexperimental group1and2, difference have statistical significance (p=0.000), and thecontrast between two groups has significant difference,(p=0.045).②the rats plasmaTNFα declined obviously in experimental group1and2, difference have statisticalsignificance (p=0.000), and the contrast between two groups has significant difference,(p=0.043).Conclusion1. Rats’s exercise tolerance decreases under high tempreture&humidity. Itdecreases to be as1/4as its normal level2. After exhaustive exercise under normal tempreture, the damage to rats’organ mainly shows as edema and acute inflammation, rarely see tissue and cellnecrosis. While in the high tempreture esperiment group, a large number of various oftissue necrosis and nuclear fragmentation were seen on rats’ogans biopsy.3. TNF-α，IL-6in exertional heatstroke rat’s plasma were significantly increased,showing heat-stress and exercise may induce systemic inflammatory responsesyndrome, causing multiple organ damage, which may be one of the importantpathogenesis for exertional heatstroke.4. The study results indicated that8-OhdG increases in exertional heatstroke ratliver, and hepatocyte mitochondrial membrane potential decreased, which suggeststhat tissue ischemia and hypoxiainduce lipid peroxidation and oxidative stress andapoptosis plays an important role in liver injury and its development under exertionalheatstroke.These results indicate that heat stress the direct and indirect effects on the livertogether with sports-induced liver injury may be the pathophysiological basis ofexertional heatstroke liver damage.