Significance of Immunohistochemical Studies of Heat Shock Proteins of the HSP70 Family in the Investigation of Postresuscitative Brain Changes

Abstract

Objective: to evaluate the immunological responsiveness of various neuronal populations of heat shock proteins of the HSP 70 family and to reveal their association with the magnitude of postresuscitative neuronal morphological changes. Materials and methods. The hypoxia-highly sensitive neuronal populations of pyramidal neurons in the layer of the fifth cerebral sensomotor cortex and hippocampal sectors CA1 and CA4 throughout the postresuscitative period after 12-minute cardiac arrest were subject to a complex immunocytochemical and morphometric study. Their immunological responsiveness to the thermal shock proteins was determined by the indirect peroxidase-antiperoxidase test using the polyclonal antibodies to HSP70. The density and composition of neuronal populations were ascertained by the morphometric assay. Results. The baseline immunological responsiveness of neuronal populations has been demonstrated to be an important factor of its resistance to ischemic lesions. The authors have determined a trend in postresuscitative changes in the immunological responsiveness of neuronal populations to HSP70 and established its association with the development of nerve cell dystrophic changes. They discuss whether complex immunocytochemical and morphometric studies are promising in investigating the mechanisms of postresuscitative brain abnormality. Conclusion. By and large, the findings suggest that the role of HSP70 in maintaining the homeostasis of neuronal populations is more complex and multifactorial, as earlier considered, and it is unlikely to be restricted itself to only merely neuroprotective properties. The high baseline content of HSP70 makes a considerable contribution to the resistance of neuronal populations to ischemia-reperfusion; and the changes in the immunological responsiveness to HSP70 are closely associated with the development of pathological nerve cell changes during a postresuscitative process.