Myocardial glucose and lactate metabolism during rest and atrial pacing in humans
Myocardial glucose and lactate metabolism during rest and atrial pacing in humans
复制标题
DOI：
10.1113/jphysiol.2008.168286
复制
发表时间：
2009-05-01
影响因子：
5.5
通讯作者：
Wolfel, Eugene E.
中科院分区：
文献类型：
--
作者：
Bergman, Bryan C.;Tsvetkova, Tatiana;Wolfel, Eugene E.
在评估增加心脏工作期间的心肌基质利用方面，在人体内的数据很少。本研究测定了7名健康男性和女性(年龄49.7±-3.9岁，体重指数23.4±1.1 kg m(-2)，最大耗氧量35.5±3.0ml kg(-1)min(-1)，射血分数68±3%)在静息和心房起搏增加心脏工作时的心肌葡萄糖和乳酸代谢平衡。饮食控制3天后，将导管置入冠状静脉窦、股动脉、股静脉和周围静脉血管。在整个研究过程中，受试者接受了预先准备的持续输注[3，3，3-H-2]乳酸和[6，6-H-2]葡萄糖。在静息和心房起搏时，以大约111次/分(-1)的频率采集动脉和冠状静脉窦血样并测量冠状静脉窦血流量。静息至心房起搏心肌耗氧量增加(P=0.04)。静息状态下的净葡萄糖摄取增加(P=0.04)，抽取分数不变(静息：9.1+/-2.7%，心房起搏9.8+/-2.9%)。从静息到心房起搏，从心肌摄取到全身葡萄糖处置的百分比也增加了。从静息到心房起搏，同位素测量的乳酸摄取量也显着增加，但在抽出分数方面没有显着差异。在整个实验过程中，心肌释放乳酸，在静息和心房起搏时乳酸显著增加(P<；0.05)。心房起搏时心脏占全身乳酸的比例(15.0±-4.4%)明显高于静息时(4.9±0.9%，P=0.03)。这些数据表明：(1)在没有缺血的情况下，心肌在静息状态下不断摄取和释放乳酸，这种乳酸在心房起搏过程中会增加；(2)在体内，当动脉底物输送不变时，在葡萄糖和乳酸利用比例相似的情况下，增加的心肌做功是完成的。
There is minimal in vivo data in humans evaluating myocardial substrate utilization during increased heart work. This study was performed to determine the balance of myocardial glucose and lactate metabolism during rest and increased heart work induced by atrial pacing in seven healthy men and women (age, 49.7 +/- 3.9 years; body mass index, 23.4 +/- 1.1 kg m(-2), maximum oxygen consumption, 35.5 +/- 3.0 ml kg(-1) min(-1), ejection fraction, 68 +/- 3%). After 3 days of dietary control, catheters were placed in coronary sinus, femoral arterial and venous, and peripheral venous blood vessels. Subjects received a primed continuous infusion of [3,3,3-H-2]lactate and [6,6-H-2]glucose throughout the study. Arterial and coronary sinus blood sampling and measurements of coronary sinus blood flow were made during rest and atrial pacing at approximately 111 beats min(-1). Myocardial oxygen consumption increased (P = 0.04) from rest to atrial pacing. Net glucose uptake increased (P = 0.04) from rest to atrial pacing with unchanged fractional extraction (rest: 9.1 +/- 2.7%, atrial pacing 9.8 +/- 2.9%). The percentage of whole body glucose disposal from myocardial uptake also increased from rest to atrial pacing. Isotopically measured lactate uptake also increased significantly from rest to atrial pacing with no significant differences in fractional extraction. The myocardium released lactate throughout the experiment, which increased significantly from rest and atrial pacing (P < 0.05). The heart accounted for a significantly greater percentage of whole body lactate disposal during atrial pacing (15.0 +/- 4.4%) compared to rest (4.9 +/- 0.9%, P = 0.03). These data suggest: (1) in the absence of ischaemia the myocardium is constantly taking up and releasing lactate at rest which increases during atrial pacing, and (2) when arterial substrate delivery is unchanged, increased myocardial work is accomplished with similar proportions of glucose and lactate utilization in healthy humans in vivo.