Central Nervous System Injury In Heat Stroke

ObjectiveTo investigate the injury of central nervous system in heat stroke and its possible pathogenesis using whole genomic oligonucleotide microarrays, cytokine assay and pathological examination.Methods1. The concentrations of serum LPS, IL-1β, TNF-αand GFAP were assayed, and pathological examination of brain were made in heat stroke rats.2. The differentially expressed genes in cerebellums of heat stroke rats was screened using rat whole genomic oligonucleotide microarrays3. Thirty-seven soldiers who participated in the intensity military training under high temperature environment and 32 control soldiers who accepted the routine training were selected randomly, and their serum MDA, ICAM-1 and IL-6 levels and plasma activity of total SOD were detected.Results1. Pulmonary edema was found in most of the rats when the core temperature reached to 42℃, and convulsion appeared in almost all of the heat stroke rats. Two of 10 rats died soon after heat stroke initiated.2. Serum LPS, IL-1β,TNF-αand GFAP levels in heat stroke rats were higher than those in control group. There were no significant differnece on serum GFAP level between heat stroke group and control group.3. On H&E staining, cell shrinkage, loss of nissl substance, reducing in number of cells (Purkinje's cells and granulosa cells in erebellums of HS, neurons in hippocampus) could be found in heat stroke rats 4. By using rat whole genomic oligonucleotide microarrays,103 up-regulated genes and 21 downregulated genes were found comparing with control rats. Among them,7 up-regulated genes were related to MAPK signal transduction pathways. B3galt4 and Cblnl were the down-regulated genes which were play an important role in biosynthesis of ganglioside and regulating morphological integrity of parallel fiber-purkinje cell synapses and synaptic plasticity.5. Serum MDA, ICAM-1 and IL-6 levels of control group were lower than those of soldiers with intensity military training under high temperature environment, while the plasma activity of total SOD was higher.ConclusionsThere was severe central nervous system impairment in heat stroke, especially in cerebellum and hippocampus. MAPK signal transduction pathways might be involved the pathophysiological process of heat stroke. Some of the down-regulated genes, Cbln1 and B3galt4, might play an important role in pathogenesis of cerebellum impairment in heat stroke. Intensity military training under high temperature environment could cause marked lipid peroxidation and other impairments.