利用焦锑酸钾沉淀法和电镜—能谱技术研究失血心肌细胞内Ca^（2＋）的分布

利用焦锑酸钾沉淀法和电镜－能谱技术研究失血心肌细胞内的Ｃａ（２＋）的分布。结果表明：在失血心肌细胞的线粒体和内质网内的Ｃａ（２＋）明显增多。这一结果对探讨失血肌细胞损伤机理具有一定意义。

缺血修饰白蛋白对大鼠急性失血性心肌缺血的早期预测价值

目的:探讨缺血修饰白蛋白(ischemia-modified albumin,IMA)作为早期预测因子在大鼠急性失血性心肌缺血中的价值。方法:采用SD大鼠制作急性失血动物模型,24只大鼠(实验A组)间断放血,分别使血红蛋白(Hb)降至100、90、80、70、60 g/L,当血清IMA明显升高时处死大鼠,取心肌组织判断是否有心肌损害。24只大鼠(实验B组)间断放血,分别使Hb降至100、90、80、70、60 g/L,当血清心肌肌钙蛋白T(cTnT)、肌酸激酶同工酶(CK-MB)明显升高时处死大鼠,取心肌组织判断是否有心肌损害。另外24只大鼠进行干预实验(干预实验对照组),间断放血,分别使Hb降至100、90、80、70、60 g/L,放血的同时输注少量人血白蛋白以抑制血清IMA变化,当血清cTnT、CK-MB明显升高时处死大鼠,取心肌组织判断是否有心肌损害。结果:实验A组大鼠当Hb降至80 g/L时,血清IMA明显升高至(64.2±3.0)U/mL(P<0.05),而此时cTnT、CK-MB、NT-proBNP数值均没有明显变化。此时处死大鼠,在显微镜下观察心肌组织,未发现缺血坏死。实验B组大鼠当Hb降至60g/L时,血清IMA为(90.2±9.0)U/mL,NT-proBNP含量上升至(1 175.3±274.1)pg/mL,cTnT上升至(1.48±0.33)ng/mL,CK-MB上升至(91.8±7.0)U/L,此时IMA、NT-proBNP、cTnT、CK-MB变化均有统计学意义(P<0.05)。此时处死大鼠,在显微镜下观察心肌组织,发现有心肌坏死。干预实验对照组大鼠Hb降至不同水平时,血清IMA均无明显变化;当Hb降至60 g/L时,血清NT-proBNP含量上升至(879.8±83.5)pg/mL(P<0.05),cTnT上升至(1.03±0.02)ng/mL(P<0.05),CK-MB上升至(86.2±7.0)U/L(P<0.05)。此时处死大鼠,取其心肌组织,显微镜下观察,发现有心肌坏死。结论:血清IMA升高可用于早期预测急性失血性心肌缺血,值得进一步研究。

Antiarrhythmic Efficacy of Neferine Assessed by Programmed Electrical Stimulation in a Canine Model of Electropharmacology

An ishemic ventricular tachyarrhythmias canine model was established in open-chest dogs subjected to programmed electrical stimulation (PES)for 5-8 days after acute myocardial infarction. The electrophysiologic effects of neferine (Nef) and procainamide (PA) were observed in this model. With routine methods of PES,ventricular tachycardia (VT)and ventricular fibrillation (VF) could be reproducibly initiated. Both drugs lengthened the QTc interval (P【0.01) and effective refractory period(ERP)of normal and ischemic ventricular myocardia (NERP and IERP) respectively (P【0.01), decreased the dispersion of ERP in ischemic myocardium and the dispersion of ERP in left ventricle (P【0.01), and increased the diastolic excitability threshold of normal and ischemic ventricular myocardia (P【0.01). The two compounds prevented the PES-induced VT or VF (Nef group P【0.01, PA group P【0.05) and ischemia-induced VF (P【0.05). The results indicated that neferine and procainamide may be effective in preventing the onset of reentrant ventricular tachyarrhythmias after myocardial ischemic damage in dogs.