Optimal myocardial preconditioning in a human model of ischemia and reperfusion.
Optimal myocardial preconditioning in a human model of ischemia and reperfusion.
复制标题
人体缺血和再灌注模型中的最佳心肌预处理。
作者：
G. Cohen;T. Shirai;R. Weisel;V. Rao;F. Merante;L. Tumiati;M. K. Mohabeer;M. Borger;R. K. Li;D. Mickle
背景
腺苷(ADE)可能介导预适应(PC)的保护作用。然而，缺乏人类数据，ADE的最佳给药方法和保护机制仍未解决。
方法和结果
我们在静止的人心室肌细胞上建立了模拟“缺血”(I)和“再灌注”(R)的模型。用缺氧(PC0)、缺氧(PC16)、缺氧上清液(SUP0)、缺氧上清液(SUP16)或缺氧上清液(SUP16)加或不加ADE受体拮抗剂(SPT)或ADE脱氨酶(ADA)进行细胞损伤和代谢参数的检测。在I前、I中、I后或持续应用ADE，同时给予SPT或不给予SPT。用PKC激动剂PMA处理细胞。用蛋白激酶C(PKC)拮抗剂Calphostin-C(Calphostin-C)孵育PC细胞。检测PKC易位和PKC活性。PC0是最具保护性的。保护可通过产生最高浓度ADE的SUP0转移。SPT或ADA的保护作用消失。细胞内ATP在PC后和I/R延长后下降，外源性ADE在I前给予50mumol时保护作用最强。艾德在我身上起到了一定的保护作用。持续的ADE治疗没有提供额外的保护。ADE可防止ATP降解，但在给药后立即增加乳酸。SPT可阻断ADE的保护作用。PMA提供了保护，但Cal-C废除了这一保护。在没有SPT的情况下，ADE可刺激PKC易位和PKC活性。
结论
极大I赋极大PC。I的程度反映在上清液中ADE的浓度。最初的ATP与PC一起下降可能是在I和R之后缺乏ATP保存的原因。ADE复制了PC的保护作用，保存了ATP，并增加了乳酸的产生，可能是通过刺激糖酵解。心脏手术期间应用ADE的临床试验是必要的，以进一步确定其对人类的有益影响。
BACKGROUND
Adenosine (ADE) may mediate the protective effects of preconditioning (PC). However, human data are lacking, and the optimal method of ADE administration and the mechanism of protection remain unresolved.
METHODS AND RESULTS
We have developed a model of simulated "ischemia" (I) and "reperfusion" (R) in quiescent human ventricular cardiomyocytes. Cellular injury and metabolic parameters were assessed after various interventions: Cells were preconditioned with anoxia (PC0), hypoxia (PC16), anoxic supernatant (SUP0), or hypoxic supernatant (SUP16) with or without the ADE receptor antagonist (SPT) or ADE deaminase (ADA). ADE was applied before, during, or after I or continuously with and without SPT. Cells were treated with the PKC agonist PMA. PC cells were incubated with the protein kinase-C (PKC) antagonist Calphostin-C (Cal-C). PKC translocation and PKC activity were assessed. PC0 was most protective. Protection was transferable via SUP0, which produced the highest concentrations of ADE. Protection was lost with SPT or ADA. Intracellular ATP fell after PC and prolonged I and R. Exogenous ADE was most protective when administered before I at 50 mumol. ADE during I was partially protective. No additional protection was provided with continuous ADE treatment. ADE prevented ATP degradation but increased lactate immediately after its administration. SPT abolished the protective effects of ADE. PMA conferred protection, which was abolished with Cal-C. ADE stimulated PKC translocation and PKC activity in the absence of SPT.
CONCLUSIONS
Maximal I confers maximal PC. The degree of I is reflected in supernatant ADE concentrations. The initial ATP fall with PC may account for a lack of ATP preservation after I and R. ADE reproduces the protective effects of PC, preserves ATP, and increases lactate production, perhaps by stimulating glycolysis. Clinical trials of ADE administered during cardiac surgery are necessary to further define its beneficial effects in humans.