MYOCARDIAL-METABOLISM DURING HYPOXIA - MAINTAINED LACTATE OXIDATION DURING INCREASED GLYCOLYSIS
MYOCARDIAL-METABOLISM DURING HYPOXIA - MAINTAINED LACTATE OXIDATION DURING INCREASED GLYCOLYSIS
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DOI：
10.1016/0026-0495(90)90300-2
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发表时间：
1990-09-01
影响因子：
9.8
通讯作者：
GERTZ, EW
中科院分区：
文献类型：
--
作者：
MAZER, CD;STANLEY, WC;GERTZ, EW
在完整的动物，心肌乳酸的利用和氧化过程中缺氧还没有得到很好的理解。9只犬长期在左前降支冠状动脉和冠状窦采样导管上安装流量探头。给予[14 C]乳酸盐和[13 C]葡萄糖示踪剂或[13 C]乳酸盐和[14 C]葡萄糖以定量乳酸盐和葡萄糖氧化、乳酸盐转化为葡萄糖以及同时的乳酸盐提取和释放。将动物麻醉并暴露于90分钟的严重缺氧（PO 2 = 25 ± 0.5）。4分）。缺氧导致心率、心输出量和心肌血流量显著增加，但心肌耗氧量无显著变化。动脉/冠状窦葡萄糖和乳酸的差异从常氧到缺氧没有变化;但是，由于心肌血流量增加，葡萄糖摄取率显著增加。示踪剂测量的乳酸提取并没有减少缺氧，尽管增加了250%的乳酸释放。在缺氧期间，90%。提取的14 C-乳酸的4%由冠状窦中的14 CO2的出现所占，相比之下，88% ± 4%由冠状窦中的14 CO2的出现所占。4%。因此，除了预期的葡萄糖摄取和乳酸产生增加外，我们还观察到缺氧期间乳酸氧化增加。
In the intact animal, myocardial lactate utilization and oxidation during hypoxia are not well understood. Nine dogs were chronically instrumented with flow probes on the left anterior descending coronary artery and with a coronary sinus sampling catheter. [14C]lactate and [13C]glucose tracers, or [13C]lactate and [14C]glucose were administered to quantitate lactate and glucose oxidation, lactate conversion to glucose, and simultaneous lactate extraction and release. The animals were anesthetized and exposed to 90 minutes of severe hypoxia (PO2 = 25 .+-. 4 torr). Hypoxia resulted in significant increases in heart rate, cardiac output and myocardial blood flow, but no significant change in myocardial oxygen consumption. The arterial/coronary sinus differences for glucose and lactate did not change from normoxia to hypoxia; however, the rate of glucose uptake increased significantly due to the increase in myocardial blood flow. Tracer-measured lactate extraction did not decrease with hypoxia, despite a 250% increase in lactate release. During hypoxia, 90% .+-. 4% of the extracted 14C-lactate was accounted for by the appearance of 14CO2 in the coronary sinus, compared with 88% .+-. 4% during normoxia. Thus, in addition to the expected increase in glucose uptake and lactate production, we observed an increase in lactate oxidation during hypoxia.