Considerations in the Use of Biochemical Markers of Ischemic Injury
Considerations in the Use of Biochemical Markers of Ischemic Injury
复制标题
使用缺血性损伤生化标志物的注意事项
作者：
B. Sobel;R. Roberts;K. B. Larson
选择血液中的一种生化标志物--肌酸磷酸激酶(CPK)对心肌梗死面积的估计结果表明，心肌梗死面积是预后、心功能受损、早期室性心律失常和临床表现严重程度的重要决定因素。基于血清CPK活性系列变化的评估与形态评估密切相关，并已被用于评估治疗干预措施。任何生化标记物的改进估计都需要排除标记物的非心脏来源，并在所用的经验或基于生理学的数学模型中表征生理变化对参数的影响。因此，使用MB CPK而不是总CPK可改善心肌梗塞合并非心源性CPK释放到循环中时的酶活性估计。CPK从梗死区释放和从循环中消失的生理学模型的初步结果表明，CPK的释放可能是扩散受限的，CPK消失率相对不受严重的血流动力学紊乱或心肌梗死本身的影响。CPK在体外和原位淋巴中的大量失活强调了确定影响血液中坏死性心肌所耗尽的生化标记物比例的重要性，因为该比例是用于定量估计不可逆缺血性损伤的模型中使用的参数之一。
Results of estimation of infarct size with a selected biochemical marker in blood, creatine phosphokinase (CPK), have suggested that infarct size is an important determinant of prognosis, impaired ventricular function, early ventricular dysrhythmia, and the severity of clinical manifestations. Estimates based on serial changes in serum CPK activity have correlated closely with morphological estimates and have been employed to evaluate therapeutic interventions. Improved estimates with any biochemical marker require exclusion of noncardiac sources of the marker and characterization of the influence of physiological alterations on parameters in empirical or physiologically based mathematical models utilized. Use of MB CPK instead of total CPK therefore improves enzymatic estimates when infarction is accompanied by release of noncardiac CPK into the circulation. Preliminary results with physiologically based models of CPK release from the infarct and its disappearance from the circulation suggest that release may be diffusion-limited and that the CPK disappearance rate is relatively uninfluenced by profound hemodynamic derangements or myocardial infarction per se. The substantial inactivation of CPK in lymph in vitro and in situ underscores the importance of defining factors influencing the proportion of a biochemical marker depleted from necrotic myocardium appearing in blood, since the proportion is one parameter used in models employed to quantitatively estimate irreversible ischemic injury.