Chace K V, Odessey R
Circ Res. 1981 Jun;48(6 Pt 1):850-8. doi: 10.1161/01.res.48.6.850.
The ability of rabbit aorta to oxidize various substrates was studied to determine which of these compounds may be energy substrates for vascular smooth muscle (VSM). Glucose, ketone bodies, medium-chain length fatty acids, branched-chain amino acids, and glutamine all are oxidized at comparable rates on a molar basis. Some other amino acids, long chain fatty acids, pyruvate and glycerol also are oxidized, but at lower rates. The oxidation of 6 amino acids could not be detected. VSM was found to release ketone bodies when incubated in leucine beta-hydroxybutyrate or octanoate. This suggests that the acetoacetyl CoA and/or acetoacetate derived from these substrates is not completely oxidized. The oxidation rate of several substrates when measured individually is inhibited by 50-80% by the presence of a combination of other substrates in the medium. Under these conditions, glucose is a minor substrate for oxidative metabolism accounting for only 5% of O2 consumption. The oxidation rate of all the exogenous substrates together is calculated to account for less than half of the oxygen consumption; this finding indicates that an endogenous substrate must also be utilized.
研究了兔主动脉氧化各种底物的能力，以确定这些化合物中哪些可能是血管平滑肌（VSM）的能量底物。葡萄糖、酮体、中链脂肪酸、支链氨基酸和谷氨酰胺在摩尔基础上的氧化速率相当。其他一些氨基酸、长链脂肪酸、丙酮酸和甘油也会被氧化，但速率较低。未检测到6种氨基酸的氧化。发现VSM在亮氨酸β-羟基丁酸酯或辛酸中孵育时会释放酮体。这表明源自这些底物的乙酰乙酰辅酶A和/或乙酰乙酸没有被完全氧化。当单独测量时，几种底物的氧化速率会受到培养基中其他底物组合的存在的抑制，抑制率为50-80%。在这些条件下，葡萄糖是氧化代谢的次要底物，仅占氧气消耗的5%。所有外源底物的氧化速率加起来计算占氧气消耗的不到一半；这一发现表明还必须利用内源性底物。
