ENERGETIC RESPONSE OF CORONARY ENDOTHELIAL-CELLS TO HYPOXIA
ENERGETIC RESPONSE OF CORONARY ENDOTHELIAL-CELLS TO HYPOXIA
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DOI：
10.1152/ajpheart.1990.258.3.h689
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发表时间：
1990-03-01
影响因子：
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通讯作者：
PIPER, HM
中科院分区：
文献类型：
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作者：
MERTENS, S;NOLL, T;PIPER, HM
在大鼠培养的冠状动脉内皮细胞中研究了内皮能量代谢对氧供应的响应，所述内皮细胞在0.1和1000 Torr之间的限定的PO 2水平。在葡萄糖（5 mM）的存在下，内皮呼吸（4 nmol O2. min-1. mg蛋白质-1）与外部PO 2> 3 Torr无关;在0.8 Torr时，氧气消耗量为最大值的一半。在100托下，乳酸盐产量为26 nmol·cm-1。min-1. mg蛋白-1; PO 2降低至0.1 Torr导致乳酸盐产量增加2.2倍。ATP，ADP，和AMP的含量分别为21，4，和2 nmol/mg蛋白质，分别，他们保持恒定的2.5小时孵育在0.1和100托之间的PO 2水平。在棕榈酸酯（100 μ M）加谷氨酰胺（0.5mM）存在下，耗氧量为8 nmol·cm-1。min-1 mg蛋白-1，并且在0.8 Torr下再次观察到半最大速率。乳酸盐的产生可以忽略不计。在PO 2水平>3托时，电池保持良好的通电。然而，低于3托，腺嘌呤核苷酸含量迅速下降。这些结果表明，冠状动脉内皮细胞的需氧量较低的跳动心肌。在葡萄糖存在的情况下，有氧糖酵解是明显的，巴斯德效应很小。在严重缺氧（PO_2 <0.1Torr）时，能态保持稳定。在没有葡萄糖的情况下，冠状动脉内皮细胞的能量状态对外部PO 2 < 3 Torr敏感，随着呼吸的减少而下降。
The response of endothelial energy metabolism to oxygen supply was studied in cultured coronary endothelial cells from the rat at defined PO2 levels between 0.1 and 1000 Torr. In the presence of glucose (5 mM), endothelial respiration (4 nmol O2 .cntdot. min-1 .cntdot. mg protein-1) was independent of the exterior PO2 > 3 Torr; oxygen consumption was half maximal at 0.8 Torr. At 100 Torr, lactate production was 26 nmol .cntdot. min-1 .cntdot. mg protein-1; the decrease of the PO2 to 0.1 Torr resulted in a 2.2-fold increase in lactate production. The contents of ATP, ADP, and AMP were 21, 4, and 2 nmol/mg protein, respectively; they remained constant for 2.5-h incubations at PO2 levels between 0.1 and 100 Torr. In the presence of palmitate (100 .mu.M) plus glutamine (0.5 mM), oxygen consumption was 8 nmol .cntdot. min-1 mg protein-1 at PO2 levels > 3 Torr, and the half-maximal rate was again observed at 0.8 Torr. Lactate production was negligible. At PO2 levels >3 Torr, the cells remained well energized. Below 3 Torr, however, the adenine nucleotide contents rapidly declined. These results demonstrate that the oxygen demand of coronary endothelial cells is low compared with the beating myocardium. In the presence of glucose, aerobic glycolysis is pronounced and the Pasteur effect small. In severe hypoxia (PO2 < 0.1 Torr) the energetic state remained stable. In the absence of glucose, the energetic state of coronary endothelial cells is sensitive to the exterior PO2 < 3 Torr, declining concomitantly with the decrease in respiration.