沙漠干热环境下中暑大鼠炎症因子与心肌损害及细胞凋亡相关性研究

摘要

Objective To explore the corelation of the inflammatory cytokine TNF -α, IL-1βand myocardial cells apoptosis in the injury of the myocardial cells of the heat stroke rats in the dry heat environment of desert .Methods Forty-eight male SD rats were randomly divided into 6 groups:mild heat stroke group and its control group , moderate heat stroke group and its control group , severe heat stroke group and its control group .Then the three experimental groups of rats were put into dry -heat environment ( temperature 41 ℃, humidity 10%) and the three control groups were put into normal environment ( temperature 25℃, humidity 35%) .After establishment of the heat stroke rat models , the rats were sacrificed at their corresponding time points (70, 110 and 145 min) from the beginning of the experiment for the mild heat stroke group and its control group , moderate heat stroke group and its control group , and severe heat stroke group and its control group , respectively .Blood samples were taken and heart tissues were harvested .The creatine kinase ( CK ) were detected by biochemical analyzer , the inflammatory cytokines TNF -α, IL-1βwere detected by ELISA method .The myocardial cells apoptosis were detected by TUNEL method .Results The cytokines TNF -α, IL-1βand CK were significantly higher in the dry heat stroke groups than those in their control groups (P<0.01), and TNF-α, IL-1βand CK showed higher and higher with the progress of the heat stroke in the groups of dry heat enviroment of the desert , and each group had significant difference compared with other group in dry heat stroke (P<0.01).The changes of the myocardial apoptosis had the same tendency as TNF -α, IL-1βand CK.The correlation analysis indicated that TNF -αand IL-1βsignificantly correlated with CK (r=0.799, 0.734, P<0.01).TNF-α, IL-1βand CK all correlated with myocardial apoptosis label indicator (LI) (r=0.577, 0.666, 0.769, P<0.01), but the correlation did not exit in the normal control groups (P>0.05).Conclusion TNF-α, IL-1βand CK increase along with the progression of heat stroke , the myocardial apoptosis induced by the inflammatory cytokine may play an important role in the injury of the myocardial cell in the heat stroke of the dry heat environment of desert.Intervening the inflammatory cytokines may be an effective method to pretect the myocardial cell from injuries caused by heat stroke under the dry heat environment of desert .%目的：探讨沙漠干热环境下中暑大鼠血清炎症因子TNF－α、IL－1β的变化与心肌细胞损害和细胞凋亡的关系。方法48只雄性SD大鼠随机平均分成六组：沙漠干热环境轻度中暑组及其常温对照组，中度中暑组及其常温对照组，重度中暑组及其常温对照组，然后将三个实验组大鼠分别置于模拟沙漠干热环境中（ T：41℃，湿度：10％），三个对照组大鼠置于常温环境（ T：25℃，湿度35％）中，在建立沙漠干热环境中暑大鼠模型后，干热环境组及其对照组分别在实验开始70 min（轻度中暑）、110 min（中度中暑）、145 min（重度中暑）三个时间点麻醉处死，并留取血液标本和心肌组织，检测血清肌酸激酶（ CK），用ELISA 法检测大鼠血清TNF－α、IL－1β；用TUNEL法检测大鼠心肌细胞凋亡并计算心肌细胞凋亡率。结果干热中暑各组大鼠血清TNF－α、IL－1β、CK均明显高于相对应的常温对照组（P＜0.01）；随着中暑程度加重，TNF－α、IL－1β、CK三者均明显增加，各组之间差异有统计学意义（ P＜0.01）。干热中暑各组大鼠心肌凋亡细胞指数变化趋势与炎症因子（TNF－α、IL－1β）和心肌酶（CK）变化趋势一致（P＜0.01），相关性分析提示沙漠干热组TNF－α、IL－1β与CK相关（相关系数分别为0.799、0.734，P＜0.01），TNF－α、IL－1β、CK三者均与心肌细胞凋亡相关（相关系数分别为0.577、0.666、0.769，P＜0.01），常温环境组无上述相关性（ P＞0.05）。结论沙漠干热环境下TNF－α、IL－1和CK随着中暑程度的加重而增加明显，在沙漠干热环境中暑发生过程中炎症因子诱导的心肌细胞凋亡参与了心肌损害的进程。同时提示，干预炎症因子诱导的细胞凋亡可能是沙漠干热环境下中暑心肌保护的重要措施之一。