title: Beneficial effects of hypothermic reperfusion on metabolic and functional recovery after cold storage of the rat heart.
abstract: With an isolated rat heart preparation, we evaluated the effects of hypothermic reperfusion on myocardial metabolic and functional recovery after cold storage. Hearts in group 1 were reperfused at normothermia (35 degrees C) after 3 hours of cold (5 degrees C) storage, and hearts in group 2 were reperfused at 20 degrees C and gradually rewarmed to 35 degrees C during 20 minutes of Langendorff (nonworking) perfusion. Coronary vascular resistance in group 1 increased progressively, whereas that in group 2 tended to decrease during the early period of reperfusion. Total creatine kinase leakage during the initial 20 minutes of reperfusion was less in group 2 (0.87 +/- 0.13 IU/heart) than in group 1 (2.48 +/- 0.32 IU/heart, p less than 0.01). Hearts in group 2 showed a better recovery of energy charge (0.850 +/- 0.020) than did those in group 1 (0.787 +/- 0.013, p less than 0.05) at 5 minutes of reperfusion. Adenosine triphosphate (ATP) and total adenine nucleotide contents in group 2 exceeded those in group 1 (ATP, 18.0 +/- 1.8 and 13.4 +/- 0.8 mumol/gm dry weight; total adenine nucleotide, 22.7 +/- 1.5 and 17.8 +/- 1.0 mumol/gm dry weight, respectively, both p less than 0.05) at 20 minutes of reperfusion. Functional recovery at 60 minutes of reperfusion was better in group 2 than in group 1 (50.3 +/- 5.8% and 30.6 +/- 4.2%, respectively, p less than 0.01). These findings indicate that hypothermic reperfusion reduces the extent of myocardial damage and improves the oxygen supply and demand balance during the early period of reperfusion; hence there is a better recovery of heart function.
mesh_terms: D000818:Animals; D004734:Energy Metabolism; D006321:Heart / Q000502:physiology; D007036:Hypothermia, Induced; D009206:Myocardium / Q000378:metabolism; D009926:Organ Preservation; D010477:Perfusion; D051381:Rats; D011919:Rats, Inbred Strains