慢性仪器化猪心肌顿抑延迟预处理的决定因素。
Determinants of delayed preconditioning against myocardial stunning in chronically-instrumented pigs.
机构信息
VA Western New York Health Care System at Buffalo, the Center for Research in Cardiovascular Medicine and the Division of Cardiovascular Medicine, Department of Medicine, University at Buffalo, Buffalo, NY, USA.
出版信息
J Cardiovasc Transl Res. 2009 Mar;2(1):71-80. doi: 10.1007/s12265-008-9081-6.
To test the hypothesis that a critical stenosis prevents delayed preconditioning against stunning, studies were conducted in pigs chronically-instrumented with occluders and segment-shortening crystals. In the setting of a critical stenosis, a preconditioning stimulus of repetitive brief occlusions resulted in infarction. Thereafter, a single 10-minute occlusion was used as the preconditioning stimulus. Delayed preconditioning against stunning was documented on subsequent days by the deficit-of-function following brief repetitive occlusions. In contrast to experiments in the naïve heart, the deficit-of-function improved on the day after a single 10-minute occlusion (from 60+/-14 to 24+/-6 arbitrary units, p=0.003), and similar improvement occurred when reperfusion was performed through a critical stenosis (32+/-6 units, p=0.02 vs. naïve and p=0.34 vs. no stenosis). Delayed preconditioning also reduced the frequency of ventricular fibrillation, and produced a 4-fold increase in both calcium-dependent and calcium-independent NOS activity. Thus, a critical stenosis did not prevent delayed preconditioning against stunning.
为了验证“狭窄病变会阻止迟发性预处理以防止心肌顿抑”这一假说，本研究采用慢性阻塞器和节段缩短晶体对猪进行了实验。在临界狭窄病变的情况下，重复短暂阻塞的预处理刺激会导致梗塞。此后，单次 10 分钟的阻塞被用作预处理刺激。随后通过短暂重复阻塞后的功能缺陷来记录迟发性预处理对心肌顿抑的保护作用。与在正常心脏中的实验相比，单次 10 分钟阻塞后的功能缺陷在一天后得到改善（从 60+/-14 到 24+/-6 个任意单位，p=0.003），并且当通过临界狭窄病变进行再灌注时也出现了类似的改善（32+/-6 个单位，p=0.02 与正常组相比，p=0.34 与无狭窄病变组相比）。迟发性预处理还降低了心室颤动的频率，并使钙依赖性和钙非依赖性 NOS 活性增加了 4 倍。因此，临界狭窄病变并不能阻止迟发性预处理以防止心肌顿抑。
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