Acquisition and decay of heat-shock-enhanced postischemic ventricular recovery

Abstract

Hyperthermia induces the synthesis of the 71-kDa heat-shock protein (heat-shock response) in all rat tissues, including heart. We examined whether induction of the heat-shock response alters the response of isolated hearts to ischemia and reperfusion. Anesthetized male rats were pretreated with 15 min of hyperthermia (42 degrees C) and then recovered for 0, 24, 48, 96, or 192 h. Hearts were isolated from control and hyperthermia-treated rats and retrogradely perfused. Greatest recovery occurred in 48-h postheat-shock hearts; after 30 min of reperfusion there was a 38, 62, and 62% recovery of force, +dF/dt, and -dF/dt, respectively, and 17, 36, and 30% recovery, respectively, for the control hearts. Creatine kinase efflux during reperfusion was reduced by 75% for 24-h postheat-shock hearts. The antioxidative enzyme catalase was increased 24, 48, and 96 h posthyperthermia. Treatment of rats with 3-amino-1,2,4-triazole (1 g/kg body wt), which irreversibly inactivates catalase, 30 min before isolation of hearts, abolished the hyperthermia-induced enhancement of postischemic recovery. These results show a strong relationship between the acquisition and decay of the enhanced postischemic ventricular recovery and the hyperthermic induction of the heat-shock response indicated by the accumulation of heat-shock protein HSP71 (mol mass 71 kDa) and the increase in catalase activity.

Impact of hyperthermic preconditioning on postischemic hepatic microcirculatory disturbances in an isolated perfusion model of the rat liver

“…They showed a strong relationship between the acquisition and decay of the postischemic ventricular recovery of the heart and the induction of HSP70. 30 In contrast, Currie et al 31 demonstrated that in spite of easily detectable expression of HSP70, hyperthermia-induced myocardial protection was observed only transiently at 24 hours and dissipated by 40 hours. These studies show that the protective effect of stress preconditioning does not always correlate with HSP70 induction.…”

“…18,28,29 So far, few attempts have been made to examine the time-dependent protective effect of hyperthermic preconditioning. Karmazyn et al 30 studied the time course of HSP70 induction at 0, 24, 48, 96, and 192 hours following whole-body hyperthermia. They showed a strong relationship between the acquisition and decay of the postischemic ventricular recovery of the heart and the induction of HSP70.…”

Insulin-induced myocardial protection in isolated ischemic rat hearts requires p38 MAPK phosphorylation of Hsp27

“…Thirty minutes of ischemia causes substantial cellular injury in control hearts as indicated by release of creatine kinase and disruption of mitochondria (13,34) particularly with reperfusion. Improved myocardial function after ischemia is associated with minimal release of creatine kinase and maintenance of cellular morphology, and such protection has been repeatedly associated with elevated expression of Hsp70 (13,34,46,59). However, in the current study, the improved myocardial function is unlikely to be due to elevated levels of Hsp70 or Hsp27.…”

Nitric oxide donor induces HSP70 accumulation in the heart and in cultured cells

“…Our results supplement this picture: NO can operate as a factor initiating the synthesis of the stress protein HSP70. Taking into account that HSP70 plays an important role in stress and adaptive responses of the organism [1][2][3][4][5][6][7], the present results allow us to classify the system of NO generation as one that determines the resistance of the organism to stress as well as the adaptive capacity of the organism.…”

“…[1,2]. HSP70 plays an important role in the restriction of stress damage [3] and in enhancing the resistance of the heart to ischemia and reperfusion after heat shock [4,5], ischemic preconditioning [6], and adaptation to stress [7]. At the same time, the question of what cell mechanisms are involved in the activation of HSP70 synthesis remains open in many respects.…”