Solomon M A, Jeffrey F M, Storey C J, Sherry A D, Malloy C R
Department of Internal Medicine, Mary Nell and Ralph B. Rogers Magnetic Resonance Center, University of Texas Southwestern Medical Center at Dallas 75235-9085, USA.
Magn Reson Med. 1996 Jun;35(6):820-6. doi: 10.1002/mrm.1910350606.
Several substrates are available in vivo for oxidation by the myocardium. Although substrate selection has been studied extensively in normoxic myocardium, relatively little is known about substrate preference very early during reperfusion after ischemia. Carbon-13 isotopomer analysis was used to study substrate usage by nonischemic and reperfused-ischemic myocardium in a working heart that was subjected to 15 min or regional ischemia and reperfused for 5 min. Compared with nonischemic myocardium, the contribution of acetoacetate to acetyl coenzyme A was increased in the reperfused-ischemic region, and the contribution of exogenous lactate was decreased. Free fatty acid oxidation, however, was not different in the two regions. These results indicate that (1) early during reperfusion, ketone body oxidation may be more significant than has been emphasized, (2) the relative contribution of fatty acids to acetyl coenzyme A is not sensitive to ischemia followed by reperfusion, and (3) Carbon-13 magnetic resonance spectroscopy methods may be used for analysis of spatial heterogeneity of metabolism in the heart.
体内有几种底物可供心肌进行氧化。尽管在常氧心肌中对底物选择已进行了广泛研究，但对于缺血后再灌注早期的底物偏好了解相对较少。采用碳 - 13 同位素异构体分析方法，研究在工作心脏中经历 15 分钟局部缺血并再灌注 5 分钟后的非缺血心肌和缺血再灌注心肌对底物的利用情况。与非缺血心肌相比，缺血再灌注区域中乙酰乙酸对乙酰辅酶 A 的贡献增加，外源性乳酸的贡献降低。然而，两个区域的游离脂肪酸氧化没有差异。这些结果表明：（1）在再灌注早期，酮体氧化可能比之前所强调的更为显著；（2）脂肪酸对乙酰辅酶 A 的相对贡献对缺血后再灌注不敏感；（3）碳 - 13 磁共振波谱方法可用于分析心脏代谢的空间异质性。
