控制性降压下不同程度的低血压对大鼠cTnI的影响研究

目的观察硝普钠(SNP)复合艾司洛尔(ESM)控制性降压下持续不同程度的低血压对大鼠心肌细胞cTnI的影响,研究控制性降压下心肌对不同程度低血压的耐受能力。方法 24只纯种雄性大鼠随机分成4组(n=6):A组为对照组,不予降压干扰,B组MAP降压至50mmHg持续1h,C组MAP降压至40mmHg持续1h,D组MAP降压至30mmHg持续1h。24h后取大鼠心脏组织做HE染色,用免疫组化的方法观察心肌细胞cTnI的表达。结果 HE染色:A、B组心肌细胞呈梭形,核清蓝色,肌纤维呈深红色,胞浆淡红色;C、D组开始出现不同程度水肿。免疫组化染色:A、B组心肌细胞蓝染,而C、D组开始出现不同程度黄染。结论硝普钠(SNP)复合艾司洛尔(ESM)控制性降压至50mmHg持续1h,大鼠心肌未出现明显损伤;降压至40mmHg及30mmHg持续1h时,大鼠心肌出现不同程度的损伤。

Effects of Deliberate Hypotension at Different Levels on Cardiac Troponin in Rats

Objective To observe the effects of sodium nitroprusside （SNP） - and esmolol （ESM） - induced hypotension at different levels on cardiac troponin （cTnl） in rats, and to study the rats＇ myocardial tolerance under deliberate hypotension at different levels. Methods Twenty - four male Sprague - Dawley rats were randomly divided into four groups. Group A （n= 6） was served as control group with normotension. Hypotension lasted for onehour was induced by SNP combined with ESM in group B Emean arterial pressure （MAP） = 50 mmHg], group C [MAP = 40 mmHg], and group D [MAP = 30 mmHg]. After 24 - hour, rats＇ cardiac tissues were studied using HE staining, and the expression of cTnl was observed by immunohistochemical SP staining. Results The results of HE staining showed that the myocardial cells of groups A and B displayed spindle- shaped, light - blue nuclear, scarlet cardiac muscle fiber, and reddish cytoplasm, while the myocardial cells of groups C and D displayed different degrees of edema. The results of immunohistochemical SP staining showed that the myocardial cells of groups A and B were light- blue nuclear, the cytoplasm in groups C and C revealed different degrees of yellow staining. Conclusions It is safe for myocardial cells of rats with deliberate hypotension lasted for one - hour induced by SNP combined with ESM at MAP = .50 mmHg, but rats display myocardial injury to a different extent when deliberate hypotension lasts for one- hour at MAP = 40 mmHg or MAP = 30 mmHg.