Author:
Bopassa J. C.,Michel P.,Gateau-Roesch O.,Ovize M.,Ferrera R.
Abstract
We hypothesized that low-pressure reperfusion may limit myocardial necrosis and attenuate postischemic contractile dysfunction by inhibiting mitochondrial permeability transition pore (mPTP) opening. Male Wistar rat hearts ( n = 36) were perfused according to the Langendorff technique, exposed to 40 min of ischemia, and assigned to one of the following groups: 1) reperfusion with normal pressure (NP = 100 cmH2O) or 2) reperfusion with low pressure (LP = 70 cmH2O). Creatine kinase release and tetraphenyltetrazolium chloride staining were used to evaluate infarct size. Modifications of cardiac function were assessed by changes in coronary flow, heart rate (HR), left ventricular developed pressure (LVDP), the first derivate of the pressure curve (dP/d t), and the rate-pressure product (RPP = LVDP × HR). Mitochondria were isolated from the reperfused myocardium, and the Ca2+-induced mPTP opening was measured using a potentiometric approach. Lipid peroxidation was assessed by measuring malondialdehyde production. Infarct size was significantly reduced in the LP group, averaging 17 ± 3 vs. 33 ± 3% of the left ventricular weight in NP hearts. At the end of reperfusion, functional recovery was significantly improved in LP hearts, with RPP averaging 10,392 ± 876 vs. 3,969 ± 534 mmHg/min in NP hearts ( P < 0.001). The Ca2+load required to induce mPTP opening averaged 232 ± 10 and 128 ± 16 μM in LP and NP hearts, respectively ( P < 0.001). Myocardial malondialdehyde was significantly lower in LP than in NP hearts ( P < 0.05). These results suggest that the protection afforded by low-pressure reperfusion involves an inhibition of the opening of the mPTP, possibly via reduction of reactive oxygen species production.
Publisher
American Physiological Society
Subject
Physiology (medical),Cardiology and Cardiovascular Medicine,Physiology
Reference37 articles.
1. Akamoto T, Yamashita C, and Okada M.Efficacy of initial controlled perfusion pressure for ischemia-reperfusion injury in a 24-hour preserved lung.Ann Thorac Cardiovasc Surg5: 21–26, 1999.
2. Preconditioning delays Ca2+-induced mitochondrial permeability transition
3. Postconditioning Inhibits Mitochondrial Permeability Transition
4. Bernardi Pand Petronelli V.The permeability transition pore as a mitochondrial calcium release channel: a critical appraisal.J Bioenerg Biomembr28: 129–136, 1996.
5. Beyersdorf F, Sarai K, Maul FD, Wendt T, and Satter P.Immediate functional benefits after controlled reperfusion during surgical revascularization for acute coronary occlusion.J Thorac Cardiovasc Surg102: 856–866, 1991.
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