Pepe Salvatore, McLennan Peter L
Cardiac Surgical Research Unit, Alfred Hospital and Baker Medical Research Institute, Monash University Faculty of Medicine, Melbourne, Australia.
Circulation. 2002 May 14;105(19):2303-8. doi: 10.1161/01.cir.0000015604.88808.74.
Regular fish consumption is associated with low cardiovascular disease morbidity and mortality. Fish oils modify cardiac membrane phospholipid fatty acid composition with potent antiarrhythmic effects. We tested the effects of dietary fish oil on ventricular hemodynamics and myocardial oxygen consumption (MVO2).
Male Wistar rats were fed for 16 weeks on a reference diet rich in n-6 polyunsaturated fatty acids (PUFA), a diet rich in saturated animal fat (SAT), or a diet rich in n-3 PUFA from fish oil. Isolated working hearts were perfused with porcine erythrocytes (40% hematocrit) at 75 mm Hg afterload with variable preload (5 to 20 mm Hg) or with low coronary flow ischemia with maintained afterload, preload, and heart rate, then reperfused. MVO2 was low and coronary perfusion reserve high in n-3 PUFA hearts, and cardiac output increased with workload. The n-3 PUFA reduced ischemic markers-acidosis, K+, lactate, and creatine kinase-and increased contractile recovery during reperfusion. SAT hearts had high MVO2, low coronary perfusion reserve, and poor contractile function and recovery. Dietary differences in MVO2 were abolished by KCl arrest (basal metabolism) or ruthenium red (3.4 micromol/L) but not by ryanodine (1 nmol/L). Fish oil or ryanodine, but not ruthenium red, prevented ventricular fibrillation in reperfusion.
Dietary fish oil directly influenced heart function and improved cardiac responses to ischemia and reperfusion. The n-3 PUFA reduced oxygen consumption at any given work output and increased postischemic recovery. Thus, direct effects on myocardial function may contribute to the altered cardiovascular disease profile associated with fish consumption.
经常食用鱼类与心血管疾病的低发病率和死亡率相关。鱼油可改变心脏膜磷脂脂肪酸组成，具有强大的抗心律失常作用。我们测试了膳食鱼油对心室血流动力学和心肌耗氧量（MVO2）的影响。
将雄性Wistar大鼠分别用富含n-6多不饱和脂肪酸（PUFA）的参考饮食、富含饱和动物脂肪（SAT）的饮食或富含鱼油n-3 PUFA的饮食喂养16周。在75 mmHg后负荷下，用猪红细胞（血细胞比容40%）灌注离体工作心脏，预负荷可变（5至20 mmHg），或在维持后负荷、预负荷和心率的情况下进行低冠状动脉血流缺血，然后再灌注。n-3 PUFA组心脏的MVO2较低，冠状动脉灌注储备较高，心输出量随工作量增加。n-3 PUFA降低了缺血标志物——酸中毒、钾离子、乳酸和肌酸激酶——并增加了再灌注期间的收缩恢复。SAT组心脏的MVO2较高，冠状动脉灌注储备较低，收缩功能和恢复较差。KCl停搏（基础代谢）或钌红（3.4 μmol/L）可消除MVO2的饮食差异，但ryanodine（1 nmol/L）不能。鱼油或ryanodine可预防再灌注时的心室颤动，但钌红不能。
膳食鱼油直接影响心脏功能，改善心脏对缺血和再灌注的反应。n-3 PUFA在任何给定的工作输出下都降低了耗氧量，并增加了缺血后的恢复。因此，对心肌功能的直接影响可能有助于改变与鱼类消费相关的心血管疾病状况。
