PRECONDITIONING IN ISOLATED SUPERFUSED HUMAN MUSCLE.
J MOL CELL CARDIOL
1349 - 1357.
Studies in isolated superfused rabbit papillary muscles indicate that preconditioning (PC) is not confined to arterially perfused myocardium. In the present study PC of isolated human right atrial trabeculae was investigated avoiding the problems of invasive experimentation in patients. Atrial trabeculae were suspended in an organ bath, superfused with Tyrode's solution and field stimulated at 1 Hz. After stabilization, muscles were randomly allocated to five groups (n = 8 per group). Control (C) muscles had no additional treatment. PC was induced by 3 min rapid pacing at 3 Hz with hypoxic. substrate-free buffer, followed by reoxygenation with substrate for 12 min. In two additional groups 8-p-sulfophenyltheophylline (SPT) was added to the superfusate either during stabilization in controls (C + SPT) or during preconditioning (PC + SPT). In the final group, R-phenyl-isopropyl adenosine (R-PLA) was added to the superfusate for 5 min to see whether or not this could substitute for preconditioning. Air muscles were then exposed to 90 min hypo;da with no substrate and pacing at 3 Hz, followed by 120 min reoxygenation at 1 Hz. Recovery of developed tension was significantly improved by PC (46.5 +/- 2.4% v 24.6 +/- 2.3% in controls) and this protective effect was blocked by the addition of SPT without adversely affecting controls (recovery in PC + SPT, 25.8 +/- 4.1% and C + SPT, 22.7 +/- 2.9%). R-PVA protected the muscles to a similar extent as PC (43.8 +/- 1.9%). These data provide evidence for the involvement of adenosine in preconditioning in human myocardium.
|Title:||PRECONDITIONING IN ISOLATED SUPERFUSED HUMAN MUSCLE|
|Keywords:||PRECONDITIONING, HUMAN ATRIAL TRABECULAE, HYPOXIA, REOXYGENATION, MYOCARDIAL PROTECTION, ACUTE MYOCARDIAL-INFARCTION, A1 ADENOSINE RECEPTORS, ISOLATED RAT-HEART, CORONARY-OCCLUSION, POTASSIUM CHANNELS, CANINE MYOCARDIUM, RABBIT HEART, ISCHEMIA, DOGS, SIZE|
|UCL classification:||UCL > School of Life and Medical Sciences > Faculty of Population Health Sciences > Institute of Cardiovascular Science|
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