Objective: Cytoplasmic members of the heat shock protein HSP70, family, inducible HSP72 and constitutive HSC73, are known to protect cells and organisms against harmful factors including ischemia, trauma, etc. The up-regulation of HSP70 was shown to greatly increase resistance of myocardial cells in vitro as well as in transgenic animals. It seems reasonable to expect that in patients undergoing open heart surgery cytoplasmic HSP70 should play a protective role, reducing the risk of the myocardial cell injury.
Methods: Using Western blotting, we determined levels of HSP72 and HSC73 in myocardium and peripheral blood lymphocytes of 51 patients with coronary and valvular diseases. In all the cases, HSP70 was detected in samples of the right atria before and after cardiopulmonary bypass.
Results: Induction of HSP72 was observed in 40% of all patients and correlated with the endurance of cardiopulmonary bypass and with disease duration in 33 patients with coronary artery disease. The cardioprotective effect of the elevated pre-operational level of HSP72 was shown to correlate with the lower activity of cardiospecific enzymes in the coronary disease patients. The HSC73 level in the right atria did not depend on conditions of the open heart surgery, while in some cases, it was increased after bypass. No correlation has been found between preoperational content of HSP72/HSC73 in lymphocytes and its pre- or post-bypass content in myocardium.
Conclusion: HSP72 is implicated in cardioprotection in combination with some other factors, and its pre-operational level, among other parameters, might be of prognostic value.