Høst N, Peuhkurinen K, Haunsø S, Hassinen I
Department of Cardiology and Internal Medicine, Rigshospitalet, University of Copenhagen, Denmark.
Cardiovasc Res. 1992 May;26(5):502-7. doi: 10.1093/cvr/26.5.502.
The sequelae of myocardial ischaemia can in principle be alleviated by repeated reperfusion, but the accumulation of adenosine monophosphate (AMP) and the loss of interstitial adenosine may lead to adenylate depletion. Repeated oxidative stress could predispose the heart to reperfusion injury. The aim of this study was to investigate the effect of intermittent reperfusion on myocardial energetics and postischaemic function.
Isolated retrogradely perfused rat hearts were subjected to 20 min ischaemia, this being continuous in group I while the hearts in group II were reperfused for three 2 min periods at 5 min intervals. Function and energy metabolism were evaluated during the postischaemic reperfusion.
Considerable efflux of adenosine compounds was seen during the final reperfusion, this being greater in group I than in group II, at 6.6(SEM 0.9) v 2.0(0.4) mumol.g-1 dry weight (p < 0.01). Tissue AMP, inorganic phosphate, and adenosine catabolites were higher in group I than in II after the ischaemic insult (p < 0.02), and ATP was higher in group II at the end of the final reperfusion (p < 0.05). All the hearts recovered; however, in group I the rate-pressure product was lower than in group II.
Repetitive reperfusion, although short in duration, is beneficial in ischaemia in terms of lower adenylate loss and better postischaemic recovery. This should be taken into consideration when designing clinical reperfusion interventions.
原则上，心肌缺血的后遗症可通过反复再灌注得到缓解，但单磷酸腺苷（AMP）的积累和间质腺苷的丢失可能导致腺苷酸耗竭。反复的氧化应激可能使心脏易患再灌注损伤。本研究的目的是探讨间歇性再灌注对心肌能量代谢和缺血后功能的影响。
对离体逆行灌注的大鼠心脏进行20分钟缺血处理，I组为持续缺血，II组心脏在5分钟间隔内进行3次2分钟的再灌注。在缺血后再灌注期间评估心脏功能和能量代谢。
在最后一次再灌注期间观察到腺苷化合物大量外流，I组比II组更明显，分别为6.6（标准误0.9）μmol·g-1干重和2.0（0.4）μmol·g-1干重（p<0.01）。缺血损伤后，I组的组织AMP、无机磷酸盐和腺苷分解代谢产物高于II组（p<0.02），最后一次再灌注结束时，II组的ATP更高（p<0.05）。所有心脏均恢复；然而，I组的速率-压力乘积低于II组。
尽管再灌注持续时间较短，但反复再灌注在降低腺苷酸损失和改善缺血后恢复方面对缺血有益。在设计临床再灌注干预措施时应考虑这一点。
