Astudy Of Lung Injury In Heat Stroke Rats In Dry Heat Environment Of Desert

Objective: The extremely dry-hot environment of desert are easily lead to heatstroke, in turn, lead tomultiple organ damage.This study is to explore the changes of lung injury in heat stroke rats in dry heatenvironment of desert.Methods:48male SD rats were randomly divided into6groups: mild heat stroke group and its controlgroup, moderate heat stroke group and its control group, severe heat stroke group and its control group.Then the3experiment groups of rats were taken into dry heat environment（T：41℃，HR：10％）,and the3control groups were taken into normal temperature environment（T：25℃， HR35%）.After theestablishment of the heat stroke rat models,the rats were sacrificed at their corresponding time point,which was:70minutes,110minutes,145minutes from the beginning of the experiment for mild heat strokegroup and its control group, moderate heat stroke group and its control group, severe heat stroke group andits control group, respectively. specimens from the bronchoalveolar lavage fluid (BALF) and lung tissuewere harvested.Pathological changes with HE staining were observed and lung injury pathological scorewere performed; Lung wet to dry weight ratio were calculated, the total protein of BALF were measured;the concentraion of MDA in lung tissue were detected.Result: Histopathological observation shows that the changes such as bronchial neutrophil accumulation,lung congestion, edema and widened alveolar septum were more serious in the heat stroke group than theircontrol group.The lung injury getting serious with the exposure time to the dry heat environment andprogression of the heat stroke.The lung injury pathological scores of heatstroke group are （3.25±0.5）、（6.5±0.58）、（8±0.82）, the lung wet-dry weight ratio are (3.5±0.57)、（4.85±0.19）、（4.10±0.07）, the lunglavage fluid total protein are（93.51±5.54）、（141.24±6.07）、（160.76±6.74）and the concentration of MDAare（1.79±0.08）、（2.79±0.11）、（3.52±0.36）.The lung injury pathological scores of the control group are（1.25±0.5）、（1.0±0）、（1.25±0.5），the lung wet-dry weight ratio are (1.78±0.66)、（1.67±0.68）、（1.67±0.25），the lung lavage fluid total protein are （42.6±8.67）、（45.25±6.78）、（41.68±3.62）, theconcentration of MDA are (1.21±0.12）、（1.20±0.12）、（1.28±0.19）.The heatstroke group were higherthan their control group. Except for the lung wet-dry weight ratio, they were all getting serious with thetime going and progression of the heat stroke, and the peak of lung wet to dry weight ratio appeared atmoderate heat stroke period. All these indicators were positively correlated with lung injury pathologicalscores(P<0.01).Conclusion: The heat stroke in dry heat environment of desert can cause lung injury in rats, anddeteriorated with the exposure time to the dry heat environment and progression of the heat stroke.Whichindicated that protection and treatment of lung injury should be pay more attention in the therapy of heatstroke in the dry heat envionment of desert.