Weisel R D, Mickle D A, Finkle C D, Tumiati L C, Madonik M M, Ivanov J
Division of Cardiovascular Surgery, Toronto General Hospital, Ontario, Canada.
Ann Thorac Surg. 1989 Oct;48(4):503-7. doi: 10.1016/s0003-4975(10)66850-6.
Previous studies have demonstrated that both myocardial metabolism and ventricular function were depressed after blood cardioplegic arrest for elective coronary artery bypass grafting. To evaluate the etiology of this metabolic defect, we measured the levels of adenine nucleotides and their precursors in 29 patients undergoing elective coronary revascularization. Myocardial biopsy specimens were obtained at 37 degrees C before cardioplegic arrest, immediately after 74 +/- 4 minutes of cardioplegic arrest, and after 30 minutes of reperfusion. Biopsy specimens were analyzed for levels of adenine nucleotides and their precursors by high-performance liquid chromatography. Adenosine triphosphate concentrations decreased with cardioplegic arrest and with reperfusion. Adenosine monophosphate concentrations increased after cardioplegic arrest and remained nearly twice the initial values after reperfusion. The ratio of adenosine monophosphate to adenosine triphosphate doubled after reperfusion, suggesting defective conversion of adenosine monophosphate to adenosine triphosphate. Levels of adenine nucleotide degradation products (adenosine, inosine, and hypoxanthine) increased after cardioplegia and decreased with reperfusion, suggesting a washout of soluble precursors. This study suggests that improvements in myocardial protection should attempt to stimulate mitochondrial energy production and preserve adenine nucleotide precursors.
先前的研究表明，在择期冠状动脉搭桥术采用冷血心脏停搏后，心肌代谢和心室功能均受到抑制。为了评估这种代谢缺陷的病因，我们测定了29例行择期冠状动脉血运重建术患者的腺嘌呤核苷酸及其前体水平。在心脏停搏前37℃时、心脏停搏74±4分钟后即刻以及再灌注30分钟后获取心肌活检标本。通过高效液相色谱法分析活检标本中的腺嘌呤核苷酸及其前体水平。三磷酸腺苷浓度随心脏停搏和再灌注而降低。单磷酸腺苷浓度在心脏停搏后升高，再灌注后仍几乎是初始值的两倍。再灌注后单磷酸腺苷与三磷酸腺苷的比值增加了一倍，提示单磷酸腺苷向三磷酸腺苷的转化存在缺陷。腺嘌呤核苷酸降解产物（腺苷、肌苷和次黄嘌呤）的水平在心脏停搏后升高，再灌注后降低，提示可溶性前体物质被清除。本研究表明，改善心肌保护应尝试刺激线粒体能量产生并保留腺嘌呤核苷酸前体。
