The role of hsp70 and IP3-DAG mechanism in the adaptive stabilization of structures and heart protection.

This study has shown that the maximal activation of the IP3-DAG regulatory circuit is observed on the 14th day of adaptation to repeated stresses. This activation is characterized by increased activity of phospholipase C and of the positive inotropic response of isolated heart to an alpha-agonist. Simultaneously, this activation is accompanied by the accumulation of five heat shock protein 70 (hsp70) isoforms. The IP3-DAG circuit activation and the hsp70 accumulation are accompanied by a significant increase in the cardiac resistance to post-ischemic reperfusion, as evidenced by a considerable decrease in the contracture, arrhythmias and the creatine kinase release into the perfusate. Continuation of the adaptation to repeated stresses for 28 days leads to complete reversal of the observed shifts.