七氟烷对低温环境下失血性休克猪心肌保护作用及其对信号转导及转录激活因子蛋白活性影响研究

Protective effect of sevoflurane on myocardium of pigs with hemorrhagic shock in low temperature environment and its effects study on the influence of protein activity of signal transduction and transcriptional activator

目的探讨七氟烷对低温环境下失血性休克猪心肌保护作用及其对信号转导及转录激活因子(STAT)蛋白活性的影响。方法选取24头巴马小型猪为研究对象。采用随机数字表法将其分为假手术组(S组)、失血性休克组(HS组)与七氟烷后处理组(Post/Sev组),每组各8头。术前禁食、不禁水,以3 mg/kg丙泊酚诱导气管插管,机械通气。HS组:行股动脉穿刺放血,制备HS模型;Post/Sev组:HS模型制备成功后30 min,吸入2%七氟烷30 min;S组:仅作穿刺置管,不做放血处理。实验中低温环境设定为-5℃~0℃。分别于休克前(T_(0))、休克后0.5 h(T_(1))、休克后1.0 h(T_(2))、休克后1.5 h(T_(3))、休克后2.0 h(T_(4))、休克后3.0 h(T5)及休克后4.0 h(T_(6)),检测并比较3组血清中肌酸激酶同工酶(CK-MB)水平。失血性休克4.0 h后,取心肌组织,采用酶联免疫吸附法检测肿瘤坏死因子-α(TNF-α)、白细胞介素-6(IL-6)、肌钙蛋白I(cTnI)水平。采用Western blot法测定3组磷酸化信号传导子及转录激活子1(p-STAT1)、磷酸化信号传导子及转录激活子3(p-STAT3)表达情况。光镜下观察3组心肌病理学结果。结果Post/Sev组心肌纤维排列较整齐,偶见炎性细胞浸润,较少细胞形态异常,病理学损伤较HS组明显减轻。与S组比较,HS组、Post/Sev组T_(1)~T_(6)时间点血液中CK-MB水平均显著升高,差异均有统计学意义(P<0.05);与HS组比较,Post/Sev组T_(1)~T_(6)时间点血液中CK-MB水平均显著降低,差异均有统计学意义(P<0.05)。与S组比较,HS组、Post/Sev组心肌组织中IL-6、TNF-α、p-STAT1及p-STAT3水平均显著升高,差异均有统计学意义(P<0.05);与HS组比较,Post/Sev组心肌组织中IL-6、TNF-α、p-STAT1及p-STAT3水平均显著降低,差异均有统计学意义(P<0.05)。结论七氟醚后处理可通过抑制心肌组织STAT蛋白的活性,从而减轻低温环境下失血性休克猪心肌损伤。

Objective To investigate the protective effect of sevoflurane on myocardium of hemorrhagic shock pigs under low temperature and its effect on the activity of signal transduction and transcriptional activator(STAT)protein.Methods Twenty-four Bama miniature pigs were selected as the research objects.The rats were divided into sham operation group(S group),hemorrhagic shock group(HS group)and sevoflurane post-treatment group(POST/SEV group)by random number table method,with 8 heads in each group.Before surgery,the patients were fasted and unable to stop drinking water.Tracheal intubation was induced with 3 mg/kg propofol and mechanical ventilation.HS group:femoral artery puncture and bloodletting were performed to prepare HS model.Post/SEV group:30 min after successful preparation of HS model,inhalation of 2%sevoflurane for 30 min.Group S:puncture and catheterization only,without bloodletting.The low temperature environment in the experiment was set at-5℃~0℃.The serum creatine kinase isoenzyme(CK-MB)levels in the three groups were measured and compared before(T_(0)),0.5 h(T_(1)),1.0 h(T_(2)),1.5 h(T_(3)),2.0 h(T_(4)),3.0 h(T_(5))and 4.0 h(T_(6))of shock,respectively.After hemorrhagic shock 4.0 h,the levels of tumor necrosis factor-α(TNF-α),interleukin-6(IL-6)and cardiac troponin I(cTnI)in myocardial tissue were detected by enzyme-linked immunosorbent assay.The expressions of phosphorylated signal transduction and transcriptional activator1(p-STAT1)and phosphorylated signal transduction and transcriptional activator 3(p-STAT3)in the three groups were determined by Western blot.The expressions of human phosphorylated signal transduction and transcriptional activator 1(p-STAT1)and human phosphorylated signal transduction and transcriptional activator 3(p-STAT3)in the three groups were determined by Western blot.The myocardial pathological results of 3 groups were observed under light microscope.Results The myocardial fibers in the Post/Sev group were arranged neatly,with occasional inflammatory cell infiltration and less abnormal cell morphology,and the pathological injury was significantly reduced compared with that in the HS group.Compared with the S group,the blood CK-MB level in the HS group and the Post/Sev group was significantly increased at T_(1)~T_(6) time point,with statistical significance(P<0.05).Compared with the HS group,the blood CK-MB level in the Post/Sev group was significantly decreased at T_(1)~T_(6) time point,with statistical significance(P<0.05).Compared with S group,the levels of IL-6,TNF-α,p-STAT1 and p-STAT3 in cardiac tissue of HS group and Post/Sev group were significantly increased,with statistical significance(P<0.05).Compared with the HS group,the levels of IL-6,TNF-α,p-STAT1 and p-STAT3 in the myocardial tissue of the Post/Sev group were significantly decreased,with statistical significance(P<0.05).Conclusion Post-treatment with sevoflurane can reduce the myocardial injury of pigs with hemorrhagic shock under low temperature by inhibiting the activity of STAT protein in cardiac tissue.