Lawton J S, Sepic J D, Allen C T, Hsia P W, Damiano R J
Department of Surgery, Medical College of Virginia, Richmond, USA.
Ann Thorac Surg. 1996 Jul;62(1):31-8; discussion 38-9. doi: 10.1016/0003-4975(96)00260-3.
Previous work from our laboratory has demonstrated the advantage of adenosine triphosphate-sensitive potassium-channel openers as cardioplegic agents when compared with hyperkalemic (20 mmol/L KCl) Krebs-Henseleit solution. However, Krebs-Henseleit with 20 mmol/L KCl is not an ideal hyperkalemic cardioplegia. Therefore, we investigated the hypothesis that hyperpolarized arrest with pinacidil and aprikalim could provide equal or superior myocardial protection to hyperkalemic arrest with the widely accepted St. Thomas' solution.
Myocardial protection was compared in the blood-perfused isolated parabiotic rabbit heart Langendorff model. Twenty-four hearts were protected with a 50-mL infusion of cardioplegia for a 30-minute global normothermic ischemic period followed by 30 minutes of reperfusion. Systolic function (percent recovery of developed pressure) and the diastolic properties of the left ventricle were measured. Coronary blood flow was measured throughout each experiment.
The percent recovery of developed pressure (mean +/- standard error of the mean) for St. Thomas' solution, pinacidil, and aprikalim was 53.1% +/- 5.4%, 64.0% +/- 3.0%, and 62.4% +/- 3.2%, respectively. The time (minutes) until mechanical and electrical arrest was significantly longer in the pinacidil (4.82 +/- 0.10 and 12.06 +/- 1.07) and aprikalim (3.33 +/- 0.28 and 11.12 +/- 0.94) groups when compared with the St. Thomas group (1.84 +/- 0.74, and 3.17 +/- 1.44). Coronary blood flow upon reperfusion was significantly greater in the pinacidil (16.4 +/- 2.1 mL/min) and aprikalim (19.4 +/- 2.8 mL/min) groups compared with the St. Thomas' solution group (8.0 +/- 1.0 mL/min), and this returned to baseline after 15 minutes of reperfusion.
Myocardial protection with pinacidil and aprikalim is comparable with that of St. Thomas' solution in the blood-perfused isolated rabbit heart despite prolonged mechanical and electrical activity during ischemia.
我们实验室之前的研究表明，与含20 mmol/L氯化钾的高钾克氏-亨氏溶液相比，三磷酸腺苷敏感性钾通道开放剂作为心脏停搏液具有优势。然而，含20 mmol/L氯化钾的克氏-亨氏溶液并非理想的高钾心脏停搏液。因此，我们研究了如下假设：使用匹那地尔和阿普卡林进行超极化停搏与使用被广泛认可的圣托马斯液进行高钾停搏相比，能提供同等或更好的心肌保护。
在血液灌注的联体兔心脏离体Langendorff模型中比较心肌保护效果。24颗心脏用50 mL心脏停搏液灌注保护，进行30分钟的全心常温缺血期，随后再灌注30分钟。测量收缩功能（舒张末压恢复百分比）和左心室舒张特性。在每个实验过程中测量冠状动脉血流量。
圣托马斯液、匹那地尔和阿普卡林组舒张末压恢复百分比（均值±均值标准误）分别为53.1%±5.4%、64.0%±3.0%和62.4%±3.2%。与圣托马斯组（1.84±0.74和3.17±1.44）相比，匹那地尔组（4.82±0.10和12.06±1.07）和阿普卡林组（3.33±0.28和11.12±0.94）达到机械和电停搏的时间（分钟）显著更长。再灌注时，匹那地尔组（16.4±2.1 mL/min）和阿普卡林组（19.4±2.8 mL/min）的冠状动脉血流量显著高于圣托马斯液组（8.0±1.0 mL/min），且在再灌注15分钟后恢复至基线水平。
在血液灌注的离体兔心脏中，尽管缺血期间机械和电活动持续时间延长，但匹那地尔和阿普卡林的心肌保护效果与圣托马斯液相当。
