Acidic HEPES-KH reperfusion enhances myocardial protection in immature rabbits

Abstract

To study the effects of different pH HEPES-KH reperfusate solution on immature myocardial protection, isolated perfused Langendorff model from immature rabbit hearts were developed formed. Control group (C) was perfused only with pH 7.4 HEPES-KH solution for 90 min. Ischemia/reperfusion group (group I/R) was perfused with pH 7.4 HEPES-KH solution before ischemia or after ischemia. Experimental group (group E), after ischemia,w as perfused with pH 6. 8, pH 7. 1 and pH7. 4 HEPES-KH solutions for 5 min, 5 min, and 20 min, respectively. The left ventricular function recovery, MWC, LDH and CK leakage, MDA, ATP content, and SOD activity were determined. Our results showed that the left ventricular function recovery, ATP content and SOD activity in group E were higher than those of group I/R (P<0.05). MWC, MDA content, LDH and CK leakage in group E were lower than those of group I/R (P<0.05). There findings suggested that pH paradox might be one of important mechanisms for immature myocardial ischemiareperfusion injury, and acidic perfusate, at the beginning of reperfusion, might attenuate pH paradox and ameliorate functional recovery in isolated perfused immature rabbit hearts.

Keywords

acidosis / immature myocardium / heart protection

References

[1] DochertyJ C, YangL, PieceG N, et al. . Na⁺/H⁺ exchange inhibition at reperfusion is cardioprotective during myocardial ischemia-reperfusion: 31P NMR studies. Mol Cell Biochem, 1997, 1776257-257

[2] AlbuquerqueC R, GerstenblityG, WeissR G. Importance of metabolic inhibition and cellular pH in mediating preconditioning contractile and metabolic effects in rat hearts. Cir Res, 1994, 74139-139

[3] HurtadoC, PierceG N. Inhibition of Na⁺/H⁺ exchange at the beginning of reperfusion is cardioprotective in isolated, beating adult cardiomyocytes. J Mol Cell Cardiol, 2000, 321897-1897

[4] CurrinR T, GoresG J, ThrmanR G, et al. . Protection by acidotic pH against anoxic cell killing in perfused rat liver: evidence for a pH paradox. FASEB J, 1991, 5207-207