MYOCARDIAL SUBSTRATE UTILIZATION DURING EXERCISE IN HUMANS - DUAL CARBON-LABELED CARBOHYDRATE ISOTOPE EXPERIMENTS
MYOCARDIAL SUBSTRATE UTILIZATION DURING EXERCISE IN HUMANS - DUAL CARBON-LABELED CARBOHYDRATE ISOTOPE EXPERIMENTS
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DOI：
10.1172/jci113822
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发表时间：
1988-12-01
影响因子：
15.9
通讯作者：
NEESE, RA
中科院分区：
文献类型：
--
作者：
GERTZ, EW;WISNESKI, JA;NEESE, RA
本研究的目的是研究人类中强度运动时心肌底物的利用情况。冠状窦和动脉导管插入9名健康男性受试者（平均年龄25岁以上）。6 （SD）年)。注入双碳标记同位素，通过测量心肌产生14CO2来定量底物氧化。仰卧循环测力仪运动在受试者最大氧摄取的40%时进行。运动组动脉乳酸水平显著升高（P < 0.05）。乳酸水平与乳酸同位素提取呈极显著正相关（r = 0.93; P < 0.001）。心肌乳酸同位素摄取从34.9 +-增加。6.5 .mu。静止时Mol /min为120.4 +-。36.5 .mu。运动5min时mol/min （P < 0.005）。14CO2数据表明100.4 .+-。根据同位素分析，3.5%的乳酸被氧化脱羧。心肌糖摄取随运动的增加而显著增加（P < 0.04）。[14C]葡萄糖数据显示只有26.0 .+-。8.5%的提取葡萄糖在静止状态下立即氧化，在运动过程中被氧化的百分比增加到52.6。7.3% （p < 0.01）。这项研究首次在人类中证明了中等强度运动期间外源性葡萄糖和乳酸的心肌氧化增加。
The purpose of this study was to investigate myocardial substrate utilization during moderate intensity exercise in human. Coronary sinus and arterial catheters were inserted in nine healthy trained male subjects (mean age, 25 .+-. 6 (SD) years). Dual carbon-labeled isotopes were infused, and substrate oxidation was quantitated by measuring myocardial production of 14CO2. Supine cycle ergometer exercise was performed at 40% of the subject''s maximal O2 uptake. With exercise there was a significant increase in the arterial lactate level (P < 0.05). A highly significant positive correlation was observed between the lactate level and the isotopic lactate extraction (r = 0.93; P < 0.001). The myocardial isotopic lactate uptake increased from 34.9 .+-. 6.5 .mu.mol/min at rest to 120.4 .+-. 36.5 .mu.mol/min at 5 min of exerecise (P < 0.005). The 14CO2 data demonstrated that 100.4 .+-. 3.5% of the lactate extracted as determined by isotopic analysis underwent oxidative decarboxylation. Myocardial glucose uptake also increased significantly with exercise (P < 0.04). The [14C] glucose data showed that only 26.0 .+-. 8.5% of the glucose extracted underwent immediate oxidation at rest, and during exercise the percentage being oxidized increased to 52.6 .+-. 7.3% (P < 0.01). This study demonstrates for the first time in humans an increase in myocardial oxidation of exogenous glucose and lactate during moderate intensity exercise.