The Study Of The Effect Of NLRP3 Inflammatory In Liver Injury In Rats With Exertional Heat Stroke

Heat stroke is a highly leathal medical emergency. By environmental factor and etiology, heat stroke can be classified into exertional heat stroke and classic/nonexertional heat stroke. EHS is commonly seem in young health population such as military personel, atheletes and students. It is a clinical syndrome mostly caused by physical exertion in high termperature, high humidity environment. It can lead to multiple organ failure and even death. It can severe damage the health of general population.Purpose: EHS mode in rats was used. To explore the role of inflammation in the liver injury of exertional heat stroke and to further reveal the pathogenesis of exertional heat stroke and provide a scientific basis for the safety protection of sports body under special conditions.Methods: EHS model in rats were established using 5-tracks computer control treadmill under simulated both high temperature and high humidity environment and normal temperature and normal humidity environment. Serum ALT, AST, creatinine, BUN and CK levels were examined. Gross pathological examination of liver, kidney, heart and brain were performed using HE stain. Serum IL-1βand IL-18 level were examined by ELISA. Liver expression of HMGB1 and NLRP3 were examined by western-blot.Results: Running time is the period from begin to the body core temperature(rectal temperature) reaching 42 ℃, EHS group and N-EHS rats average exercise time was 15.8±1.3min and 57±6min, the difference was statistically significant(P = 0.002). ⑵ thermoregulatory response to heat stress quantitative analysis: The core body temperature rising rate of EHS group is 42.5±3.3% and N-EHS group is 11.9±1.2%, the difference was statistically significant(P <0.001); heat load of EHS group is 8.25±0.87 and N-EHS is 29.5±8.3, the difference was statistically significant(P <0.001). Serum ALT level in EHS-0h group is higher than R group. There is no difference between N-EHS and R group, neither between N-EHS and EHS group. Serum ALT level in both N-EHS and EHS-0h groups are higher than in R groupSerum BUN and Cr level in both N-EHS and EHS-0h groups are higher than in R group(P<0.05)Serum IL-1βand IL-18 level in both N-EHS and EHS-0h groups are higher than in R group(P=0.034 and P<0.001).Hepatic NLRP3 and HMGB1 levels in EHS-12 h group are higher than in R group(P=0.032 and P<0.001).Compared to N-EHS group, liver portal area in EHS-0h showed more inflammatory cell infiltration, more severe hepatic cell edema and more spotty necrosis, Liver injury is severe.Conclusion: The exercise capacity of rats in high temperature and high humidity environment decreases. During exercise, body temperature rises in a 3 phase pattern and in a faster rate. In EHS induced liver injury, significant increase of the NLRP3 and HMGB1 wan detected in liver tissue, plasma IL-1β, IL-18 content is increased significantly, these suggest that the inflammasome pathway in the liver injury disease exertional heat stroke play an important role, which may be an important pathogenic mechanism of exertional heat stroke of a liver injury.