摘要
目的:本研究旨在探讨甲状腺激素(三碘甲状腺原氨酸,T3)替代治疗能否改善心功能和甲状腺功能,并探索最佳治疗剂量,为临床提供初步试验数据。方法:腹腔注射异丙肾上腺素(ISO)诱导心肌梗死后心力衰竭(心衰)伴甲状腺功能紊乱的动物模型,并检测血清中肌钙蛋白I(cTnI),以确定动物发生心肌梗死。将心衰大鼠随机分为4组:无治疗对照组(C-group)、低剂量T3治疗组(10μg/kg,L-group)、中剂量T3治疗组(30μg/kg,M-group)和高剂量T3治疗组(60μg/kg,H-group),连续给予T3治疗3d。定期行心脏超声心动图检查,检测游离T3(FT3)和游离T4(FT4)浓度,32d实验结束处死动物,取心脏做氯化三苯基四氮唑染色(TTC染色)。结果:①ISO诱导应激性心肌梗死模型大鼠心衰并伴有FT3、FT4降低,cTnI升高和超声心动图的改变。②给予T3替代治疗后,与C-group相比,L-group心功能明显改善,心脏超声短轴缩短率(FS)上升显著(P<0.01),血清中FT3和FT4下降幅度明显低于其他组(P<0.05);与L-group相比,M-group和H-group血清中FT3和FT4下降值、FS降低更明显,以H-group为甚;③大鼠心肌组织TTC染色提示心肌梗死重量指数各组间无明显差异,表明T3补充治疗对心功能的改善作用不依赖于显著降低心肌梗死面积。结论:严重心衰动物会出现甲状腺功能紊乱,予以适当小剂量T3补充治疗后能改善心脏功能,剂量过大反而使心功能受损。
To examine if thyroid hormone （triiodothyronine, T3 ） replacement therapy potentially improve cardiac function and find out an optimal dosage, which could provide an important information for clinical application. Method：Animal models of heart failure after myocardial infarction combined with thyroid dysfunction were created by intraperitoneal injection isoproterenol （ISO）. Troponin I（cTnI） was then tested to make sure the occurrence of the rats with myocardial infarction. The heart failure rats were then randomly devided into the fol- lowing four groups： heart failure group without any treatment （control group, C-group）, low dose T3 treatment group （10 μ/kg, L-group）, medium dose Ta treatment group （30 μg/kg, M-group） and high dose T3 treatment group（60 μg/kg, H-group）. T3 was given continuously for three consecutive days. Echocardiography was per-formed and serum FT3 and FT： were detected at regular intervals. Animals were sacrificed on 32 days and the heart of each rat was obtained for triphenyltetrazolium chloride staining （TTC staining）. Result： ①ISO injection induced myocardial infarction rats with heart failure, and resulted in decrease of FT3 and FT4, increase of cTnI, and echocardiography transformation. ②Compared with the C-group, T3 replacement therapy increased the FT3 and FT4 levels, and improved left ventricular fractional shortening （FS） remarkably in L-group, which preceded to M-group or H-group （P〈0.01）. QTTC staining demonstrated that the infarct size was not different in the four groups, and indicated that T3 replacement therapy to cardiac function improvement did not depend on the sig-nificant reduction of myocardial infarct size. Conclusion： Heart failure following myocardial infarction induced by ISO presents a low T3 level . An appropriate dose T3 replacement therapy could improve cardiac function,whereas excessive dose would potentially aggravate heart failure.
出处
《临床心血管病杂志》
CSCD
北大核心
2012年第7期549-552,共4页
Journal of Clinical Cardiology
