肝素输注期间人体心肌游离脂肪酸代谢的评估。

Dagenais G R, Marquis Y, Gailis L

Recent Adv Stud Cardiac Struct Metab. 1975;10:3-16.

Free fatty acids (FFA) have been shown to be a major myocardial substrates during the postabsorptive state in humans. In order to document the utilization of these substrates by the heart while heparin was infused, the following study was designed. During heparin infusion, total and individual FFA were measured in arterial and coronary sinus plasma during the postabsorptive state in 13 patients with coronary artery disease and in 4 patients with no evidence of cardiac disease. Oleic-1-14C acid bound to albumin was infused at a constant rate for at least 7 min into the left coronary artery. Left coronary blood flow was determined in all patients. It was assumed the oleic-1-14C acid behaves like endogenous FFA. Arterial FFA concentration was high (mean and SEM: 1 +/- 0.21 mumoles/ml) and varied by less than 10% during the course of the study in 14 of the 17 patients. Oleic acid constituted 44% of all arterial FFA. The relative concentrations of the various individual FFA were similar in arterial and coronary sinus plasma. The average FFA extraction was 19.9 +/- 2.1%. In contrast, the oleic-1-14C acid extraction was relatively more steady during the infusion, and the mean extraction of this tracer was 36.0 +/- 2.1%. Myocardial uptake for the entire group was 52.3 +/- 6.3 mumoles/min. Although a definite plateau for 14CO2 release from oleic-1-14C acid oxidation was not obtained, at least 31.8 +/- 4.3% of the removed FFA was oxidized, representing 49.3 +/- 6.4% of myocardial oxygen consumption. The failure of oleic-1-14C acid oxidation to reach a steady state was not due to delay in the myocardial CO2 pool, since 14CO2 release from infused NaH 14CO3 and lactate-1-14C in 11 other subjects revealed that in equilibrium was obtained within 5 min. These findings indicate that the generation of 14CO2 from oleic-1-14C acid oxidation is relatively slow, and the uptake of labeled FFA is partly matched by release of unlabeled FFA, suggesting that the human heart has important lipid pools.

游离脂肪酸（FFA）已被证明是人类吸收后状态下心肌的主要底物。为了记录在输注肝素时心脏对这些底物的利用情况，设计了以下研究。在输注肝素期间，对13例冠心病患者和4例无心脏病证据的患者在吸收后状态下测量动脉和冠状窦血浆中的总游离脂肪酸和单个游离脂肪酸。将与白蛋白结合的油酸-1-14C以恒定速率至少输注7分钟到左冠状动脉。测定了所有患者的左冠状动脉血流量。假定油酸-1-14C的行为类似于内源性游离脂肪酸。在17例患者中的14例中，动脉游离脂肪酸浓度较高（平均值和标准误：1±0.21微摩尔/毫升），并且在研究过程中变化小于10%。油酸占所有动脉游离脂肪酸的44%。动脉和冠状窦血浆中各种单个游离脂肪酸的相对浓度相似。游离脂肪酸的平均提取率为19.9±2.1%。相比之下，油酸-1-14C在输注期间的提取相对更稳定，该示踪剂的平均提取率为36.0±2.1%。整个组的心肌摄取量为52.3±6.3微摩尔/分钟。虽然未从油酸-1-14C酸氧化中获得14CO2释放的明确平台期，但至少31.8±4.3%的去除游离脂肪酸被氧化，占心肌耗氧量的49.3±6.4%。油酸-1-14C酸氧化未能达到稳定状态不是由于心肌二氧化碳池的延迟，因为在其他11名受试者中，输注NaH 14CO3和乳酸-1-14C后14CO2的释放表明在5分钟内达到了平衡。这些发现表明，油酸-1-14C酸氧化产生14CO2相对较慢，标记游离脂肪酸的摄取部分与未标记游离脂肪酸的释放相匹配，这表明人类心脏有重要的脂质池。