Association of GRP78 Protein Expression with the Degree of Postischemic Hippocampal Damage in Rats of Both Sexes

Abstract

Objective: to reveal an association of the changes in GRP78 protein expression with the state of hippocampal neuronal populations in the postresuscitative period. Materials and methods. Adult albino rats of both sexes underwent 10-minute cardiac arrest, followed by resuscitation. On postresuscitative days 1, 7, and 14, the density and composition of pyramidal neuronal populations in the CA1 and CA4 hippocampal sectors were determined by differentiated morpho-metric analysis and the level of GRP78 protein expression was estimated in these neuronal populations. The results were statistically processed using the ANOVA procedure (Post-hog comparisons of means). Results. Gender differences were found in the damageability of hippocampal neuronal populations after ischemia-perfusion. Thus, the resuscitated females, unlike the resuscitated males, showed postresuscitative changes only in the CA1 hippocampal sector, rather than in the CA4 one. At the same time the changes and magnitude of postresuscitative changes within one neuronal population (CA1 sector) were dissimilar in the animals of both sexes. There were trends and gender differences in the postresuscitative changes in the immune responsiveness of hippocampal CA1 and CA4 neuronal populations to GRP78 protein. Complex analysis indicated that neuronal loss occurred with a lower immune responsiveness to GRP78 and the elevated expression of GRP78 protein in the early postoperative period promoted the prevention of neuronal dystrophic changes and/or death. The findings favor the idea of the neuroprotective properties of GRP78 protein. Conclusion. The results of the present study are promising for the elaboration of new approaches to the pathogeneti-cally sounded prevention and therapy for posthypoxic encephalopathies. Key words: ischemia-reperfusion, neurons, GRP78 protein, hippocampus, gender differences.