蒲黄总黄酮对麻醉犬心肌耗氧量的影响

目的：观察蒲黄总黄酮对麻醉犬心肌耗氧量的影响。方法：采用麻醉犬冠脉流量、心肌耗氧量和心肌氧摄取率等指标的变化，研究蒲黄总黄酮对缺血心肌的作用。结果：灌胃给药30min到120min的各时间点，蒲黄总黄酮可明显增加冠脉血流量，降低心肌摄氧率和心肌耗氧量，与生理盐水组比较有显著差异（P〈0．01）。结论：蒲黄总黄酮对缺血心肌具有一定的保护作用。     

芍药苷对正常麻醉开胸犬血流动力学及心肌耗氧量的影响

目的:观察芍药苷对正常麻醉开胸犬血流动力学及心肌耗氧量的影响。方法:经十二指肠给药,以血压、左室内压、左室作功、冠脉阻力、心肌耗氧量等为观测指标,研究芍药苷对犬血流动力学及心肌耗氧量的影响。结果:芍药苷具有降低左室内压,降低左室作功指数、降低血压、降低总外周阻力、降低冠脉阻力;降低心肌耗氧量的作用。结论:芍药苷可通过增加冠脉流量,增加氧的供应,降低心肌耗氧量,改善心脏血流动力学。     

木犀草素对冠脉血流动力的实验研究

本文报道了木犀草素(Lut)10mg·kg~(-1)iv对麻醉犬具有明显扩张冠脉血流量及降低冠脉血管阻力的良好作用,而对心肌耗氧量无明显影响。     

当归对犬血流动力和心肌氧代谢的影响

本文研究了当归注射液对麻醉犬血流动力和清醒高血压犬血压和心率的作用。麻醉犬于静脉注射当归2 g/kg后,血压降低、冠脉、脑和外周血流量增加,血管阻力降低,心排出量稍增加,总外周阻力降低,心肌氧消耗量减少。清醒高血压犬静脉注射当归2 g/kg后,血压和心率均先有增加,随后减少。     

当归对犬血流动力和心肌氧代谢的影响

本文研究了当归注射液对麻醉犬血流动力和清醒高血压犬血压和心率的作用。 麻醉犬于静脉注射当归2 g/kg后,血压降低、冠脉、脑和外周血流量增加,血管阻力降低,心排出量稍增加,总外周阻力降低,心肌氧消耗量减少。 清醒高血压犬静脉注射当归2 g/kg后,血压和心率均先有增加,随后减少。     

蝙蝠葛酚性碱对犬血流动力学及冠脉循环的影响蝙蝠葛酚性碱对犬血流动力学及冠脉循环的影响

目的研究蝙蝠葛酚性碱（PAMD）对正常麻醉犬血流动力学、冠脉循环及心肌氧代谢的影响。方法设立生理盐水阴性对照组及PAMD 3.5和7.0 mg·kg^-1两剂量组，在不同时间点观察各组犬血流动力学、冠脉循环及心肌氧代谢的相关指标的改变。结果与药前相比，PAMD两剂量组均可降低左心室收缩压（LVSP）和±dP/dt_max，减慢心率，增加心肌氧含量、降低心肌氧利用率，且具有增加冠状动脉血流量，降低冠状动脉阻力和外周阻力的作用。对血压、心输出量和左室舒张末压（LVEDP）无显著影响。结论PAMD能改善血流动力学、冠脉循环及心肌氧代谢。     

参附注射液对犬急性心肌梗死的保护作用

目的:制备麻醉犬急性心肌梗死(AMI)模型,观察参附注射液对急性心肌梗死犬心肌酶学和氧摄取率的影响,初步探讨其对AMI的保护作用及可能的作用机制。方法:采用结扎冠脉法建立犬AMI模型。将健康杂种犬随机分为阴性对照组,丹参注射液组,参附注射液大、中、小剂量组,于冠脉结扎后15 min各组犬经股静脉滴注相应药物,结扎后30,60,90,120及180 min取血测氧摄取率,测定各组犬冠脉结扎前和结扎后180 min时血清中肌酸激酶(CK)、乳酸脱氢酶(LDH)、超氧化物歧化酶(SOD)以及丙二醛(MDA)的含量。结果:冠脉结扎后,阴性对照组犬血清CK、LDH和MDA含量显著升高,SOD含量明显减少,氧摄取率显著降低。与阴性对照组比较,丹参组和参附注射液各剂量组能显著对抗血清中CK、LDH和MDA活性的增高以及SOD、氧摄取率的降低。结论:参附注射液对犬AMI有一定的保护作用。     

生脉输液对麻醉犬血流动力学及心肌耗氧量的影响

目的研究生脉输液对麻醉犬血流动力学及心肌耗氧量的影响。方法将杂种犬36只,随机分为6组(每组6只):对照组、阳性药组(硝酸甘油注射液组和生脉注射液组)、生脉输液高、中、低三个剂量组。人工呼吸下开胸,观察用药前后不同时间点麻醉犬的冠脉流量(CBF)、心输出量(CO)、冠脉阻力(CAVR)、总外周阻力(TPVR)、心搏出量(SV)、心搏指数(SI)、心脏指数(CI)、左室作功(LVSW)、心肌血流量(MBF)、心肌耗氧指数(MOCI)、耗氧量(VO2)、心肌氧利用率(MOUR)等指标的变化。结果与对照组比较,生脉输液(200,100 mg生药.kg-1)能显著增加麻醉犬冠状动脉和主动脉的血流量、增加心肌血流量,降低总外周血管阻力和冠状动脉阻力,提高心搏出量和心肌氧利用率。结论生脉输液对麻醉犬血流动力学参数有改善作用,具有良好的抗心肌缺血作用。     

牡荆素对麻醉犬血流动力学及心肌耗氧量的影响

目的研究牡荆素对麻醉犬血流动力学及心肌耗氧量的影响。方法杂种犬30只,人工呼吸下开胸,给药后观察其心率（HR）、血压（MAP）、心输出量（CO）、冠脉血流量（CBF）、左室压（LVP）及血氧含量。计算冠脉阻力（CVR）和体循环总外周阻力（TPR）等血流动力学指标。采用多普勒超声血流仪测定麻醉犬冠脉流量和心输出量,用血气分析仪测定血氧含量。结果牡荆素可减慢心率和左心室内压,并显著增加麻醉犬冠脉血流量和心输出量,降低总外周血管阻力和冠脉阻力,提高心搏出量、心搏指数及心脏指数。结论牡荆素可显著改善麻醉犬血流动力学参数。     

丹参素对麻醉犬血流动力学的影响

目的观察丹参素钠注射液静注给药对正常麻醉犬心率、血压、心脏收缩舒张功能等血流动力学指标的影响。方法采用心脏导管法直接观察丹参素钠注射液（2、4、8 mg/kg）对麻醉犬心率（HR）、收缩压（SAP）、舒张压（DAP）、平均动脉压（MAP）、左心室收缩压（LVSP）、左心室平均压（MLVP）、左心室收缩压最大变化速率（±dp/dtm ax）、左心室舒张末期压（LV-EDP）等血流动力学的影响。结果丹参素钠注射液显著增加LVSP、±dp/dtm ax,对SAP、DAP、MDP无显著影响;高剂量组显著降低心率。结论丹参素钠注射液可显著改善心功能,具有减轻心脏负荷,降低心肌耗氧量的作用。     

Lack of protection of ischemic myocardium by verapamil in conscious dogs

To determine whether coronary dilation and decreased myocardial oxygen requirements resulting from administration of verapamil, a calcium and slow current antagonist, protect ischemic myocardium in conscious dogs, we studied 15 treated and 15 control animals after coronary occlusion. Verapamil (0.2–0.7 mg/kg/h) was given by continoous infusion for 17 h beginning 5 h after the initial plasma creatine kinase (CK) elevation after coronary occlusion. Observed infarct size and infarct size predicted before verapamil were estimated from hourly plasma CK values and infarct size was estimated also from myocardial CK depletion measured directly, 24 h after occlusion. Changes in heart rate, blood pressure, and frequency of premature ventricular complexes (recorded every 30 min) after occlusion were similar in treated and control dogs. Coronary flow after verapamil, measured with radioactively labeled microspheres, did not increase in ischemic zones but increased by 90% in normal myocardium (p < 0.05). The differences between observed and predicted infarct size estimated from plasma CK changes in treated and controls were similar (3.0±2.2 (S.E.) and 2.0±1.4 CK-g-eq), and myocardial CK depletion was also comparable in the two groups (25 ± 2% and 23 ±2%). Thus although verapamil, administered five hours after the initial plasma CK elevation, increased coronary flow in normal myocardium, it did not augment flow in ischemic tissue or limit the extent of infarction.     

三七提出物对心脏的药理作用

三七绒根提取物“76017”(简称17号)按1∶20000的浓度加入灌流液中,能增加离体豚鼠心脏冠脉流量。搏动心脏用17号后,冠脉流量增加84.04%,同时心肌收缩力增强,但心率变化不大;在用垂体后叶素收缩冠脉的基础上,用17号灌流,冠脉流量增加83.78%;纤颤心脏用17号灌流,冠脉流量增加65.06%。麻醉犬冠状静脉窦流出量测量。经十二指肠投予17号100mg/kg,冠脉流量增加57.03%,并能持续3小时以上,同时呈现心率减慢和血压降低。血氧测定结果,在冠脉流量增加高峰期,心肌耗氧量增加64.03%。心肌匀浆耗氧量测定。0.1%的17号抑制以丙酮酸为底物之耗氧量,增加以琥珀酸为底物之耗氧量。在实验性心肌梗塞模型上,静脉注入17号10mg/kg,未见到对心肌缺血性损害有保护作用,静脉注入心得安0.5 mg/kg,则有明显的保护作用。     

尼群的平对麻醉犬冠脉流量、心肌耗氧量、二氧化碳产生率的影响

尼群的平20μg/kg iv显著降低麻醉犬血压的过程,冠状窦流量明显增加。持续3h,冠状窦氧含量增加,氧摄取率、心肌耗氧量、二氧化碳产生率降低,持续了3h以上,说明该剂适用于高血压伴心肌缺血。     

The slow-channel calcium blocking agent, nitrendipine, and coronary collateral blood flow

The effects of a new dihydropyridine slow-channel calcium blocking agent, nitrendipine, on hemodynamics and myocardial blood flow in normal and ischemic areas distal to either an acute or chronic coronary artery occlusion were studied in anesthetized dogs. Nitrendipine produced significant and dose-related decreases in mean aortic blood pressure and increases in flow through the nonobstructed coronary artery. In acute coronary artery occlusion experiments, only small changes in perfusion of the ischemic zone were observed following nitrendipine. On the other hand, in dogs with a chronic coronary artery occlusion and well-developed collateral circulation, nitrendipine produced significant and dose-related increases in subepicardial perfusion within the central ischemic zone. No change in subendocardial blood flow during drug-induced hypotension was observed, but when aortic pressure was held constant, there was an increase in subepicardial, subendocardial, and overall transmural myocardial perfusion. The data demonstrate that nitrendipine improves oxygen supply to collateral-dependent myocardium via an increase in coronary collateral blood flow in a model of chronic coronary occlusion.     

Pentaerythritol trinitrate and glyceryl trinitrate on myocardial oxygen consumption and haemodynamics in the dog

1. The effects of pentaerythritol trinitrate (pentrinitrol) and glyceryl trinitrate on myocardial oxygen consumption and myocardial and systemic haemodynamics were studied in anaesthetized open-chest dogs. An in vivo oximeter in the coronary sinus permitted continuous determination of arteriovenous oxygen difference and myocardial oxygen consumption. All parameters were determined simultaneously at various intervals after drug administration. 2. Myocardial oxygen consumption was diminished by both nitrates for more than 16 min. Changes in arteriovenous oxygen difference and coronary sinus oxygen content were variable between drugs. Following an initial transient increase, coronary blood flow was reduced by both nitrates. Aortic blood pressure, aortic blood flow, left ventricular end-diastolic pressure and left ventricular dP/dt were also reduced. Heart rate and contractile force were not appreciably altered by either nitrate. 3. The decrease in myocardial oxygen consumption appears to be associated with the haemodynamic profile of these drugs. Both nitrates produced comparable reductions in preload (left ventricular end-diastolic pressure) and afterload (aortic pressure) as well as dP/dt.     

Effects of pinacidil on myocardial blood flow and infarct size after acute left anterior descending coronary artery occlusion and reperfusion in awake dogs with and without a coexisting left circumflex coronary artery stenosis

To determine whether partial stenosis of a second major coronary artery promoted vasodilator-induced coronary steal and increased infarct size after acute coronary artery occlusion, we produced acute myocardial infarction by 4-h left anterior descending coronary artery occlusion and 20-h reperfusion in awake dogs with and without a mild to moderate stenosis (33-72%) of the proximal left circumflex coronary artery. Dogs were randomized to receive intravenous (i.v.) normal saline or pinacidil, a new antihypertensive agent with a marked coronary dilator property, beginning 40 min after onset of coronary artery occlusion and continuing throughout the occlusion and the first hour of reperfusion. Pinacidil was titrated to decrease mean aortic pressure 25 mm Hg, which resulted in an increase in heart rate (HR), cardiac output (CO), and left ventricular (LV) dP/dt and LVdP/dt/P. Saline infusion had no effects. Blood flows to ischemic and remote myocardium did not differ between dogs with and without coronary stenosis. Pinacidil increased blood flow threefold in normal myocardium, but had no effect on infarct zone myocardial blood flow or infarct size (58 +/- 4% of region at risk vs. 56 +/- 4% in animals receiving normal saline) in dogs without coronary stenosis. In contrast, similar administration of pinacidil in dogs with coronary stenosis reduced infarct size zone myocardial blood flow and increased infarct size (69 +/- 3% vs. 55 +/- 5% in the saline group, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

葛根素对急性心肌缺血狗区域性心肌血流与心脏血流动力学的作用

麻醉开胸狗ⅳ葛根素(puerarin)可减慢心率(HR)、降低主动脉压(MAP),用同位素标记微球法测得的缺血区侧枝冠脉血流量并不减少。从狗的右室旁路制备的心脏血流动力学实验发现葛根素明显减低张力一时间指数(TTI)与左室压力升高速度(LV dp/dt)。当MAP调整到给药前的水平时,TTI与LV dp/dt恢复,进入缺血区的侧技血流增加,非缺血区的冠脉血流量(CBF)亦增加。葛根素减低冠脉血管阻力(CVR)的作用比减低全身血管阻力(SVR)的作用更显著。葛根素不影响心肌收缩力,但增加局部心肌缺血时的侧枝血流并减少与心肌氧消耗有关的血流动力学参数。这些结果提示葛根素有益于治疗心肌缺血。     

Measurement of oxygen tension in the ischemic myocardium using encased polargraphic oxygen electrodes

The ability to continuously monitor the delicate balance between blood flow and oxygen consumption would be a great asset in the study of myocardial ischemia. The present study was performed, in anesthetized dogs, to validate the use of encased polargraphic oxygen electrodes in the study of myocardial ischemia. Polargraphic oxygen electrodes were placed in the area to be rendered ischemic at fixed tissue depths of 3 mm (epicardium) and 9 mm (endocardium). Endocardial and epicardial oxygen tensions as well as the ratio of endocardial to epicardial oxygen tension and left circumflex coronary flow were monitored. Ischemia was induced by decreasing left circumflex coronary flow by 50%. Upon completion of a 20-min poststenotic period, endocardial pO₂, endocardial/epicardial ratio, and coronary flow were significantly decreased (59 ± 7, 52 ± 7, and 55 ± 4%, respectively) whereas epicardial pO₂ was slightly decreased. Nitroglycerin (10 μg/kg, i.v.) markedly increased endocardial pO₂ and endocardial/epicardial ratio above poststenotic control (13 ± 5 mmHg and 64 ± 10%, respectively) whereas epicardial pO₂ was not significantly decreased. The increases in endocardial pO₂ occurred at a point where coronary flow and mean arterial pressure were not significantly changed. Conversely, dipyridamole (125 μg/kg, i.v.) significantly increased coronary flow (26 ± 2 ml/min/100 g) although it did not appreciably alter endocardial or epicardial pO₂. It is concluded that encased polargraphic oxygen electrodes provide a quantitative method for determination of oxygen tension in the ischemic myocardium.