Heat-shock response is associated with enhanced postischemic ventricular recovery.

Abstract

In cells, hyperthermia induces synthesis of heat-shock proteins and the acquisition of thermotolerance. Thermotolerant cells are resistant to subsequent oxidative stress. In this study, heat-shocked hearts were examined for evidence of protection during ischemia and reperfusion. Rats were exposed to 15 minutes of 42 degrees C hyperthermia. Twenty-four hours later their hearts were isolated and perfused and the contractility examined during and after ischemic perfusion. No protection was observed during ischemic perfusion. However, upon reperfusion heat-shocked hearts had recovery of contractility within 5 minutes of reperfusion, while control hearts showed no contractility at this time. Throughout 30 minutes of reperfusion heat-shocked hearts had significantly improved recovery of contractile force, rate of contraction and rate of relaxation. Creatine kinase release, associated with reperfusion injury, was significantly reduced from a high of 386.8 +/- 78.9 mU/min/g heart wt for controls to 123.7 +/- 82.9 mU/min/g heart wt for heat-shocked hearts at 5 minutes of reperfusion. Following 30 minutes of reperfusion, ultrastructural examination revealed less damage of mitochondrial membranes in the heat-shocked hearts. Further biochemical investigations revealed that the antioxidative enzyme, catalase, was significantly increased to 137 +/- 12.7 U/mg protein in the heat-shocked hearts while the control value was 64.8 +/- 8.3 U/mg protein. Hyperthermic treatment, which induces the heat-shock response, may be therapeutic for salvaging ischemic myocardium during reperfusion, through a mechanism involving increased levels of myocardial catalase.

• Authors: R W Currie, M Karmazyn, M Kloc, K Mailer
• Journal: Circulation research (Circ Res) Vol. 63 Issue 3 Pg. 543-9 (Sep 1988) ISSN: 0009-7330 [Print] United States
• PMID: 3409486 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Oxidoreductases
• Creatine Kinase

Topics

• Animals
• Coronary Disease (enzymology, pathology, physiopathology)
• Creatine Kinase (metabolism)
• Electrophoresis, Polyacrylamide Gel (methods)
• Heart (physiopathology)
• Heart Ventricles
• Hot Temperature
• In Vitro Techniques
• Male
• Microscopy, Electron
• Mitochondria, Heart (ultrastructure)
• Myocardial Contraction
• Myocardium (enzymology, ultrastructure)
• Oxidoreductases (metabolism)
• Rats
• Rats, Inbred Strains
• Shock (physiopathology)