Induction of HSP70 mRNA after transient ischemia in gerbil brain

Heat shock protein (HSP) plays an important role in stress responses of cells. Inductions of HSP70 mRNA, amyloid precursor protein (APP) mRNA, and tubulin mRNA within hippocampal CA1 and parietal cortex in gerbil brains were examined at 1 h to 7 days after 10 min of bilateral common carotid artery occlusion using Northern blot analyses. In contrast to the induction of HSP70 mRNA, no induction was observed in APP mRNA or tubulin mRNA. Regional differences in the induction of HSP70 mRNA were found. CA1 cells produced less amount of HSP70 mRNA than cortical cells at 8 h after the transient ischemia. Transient global ischemia is known to result in the selective neuronal death of hippocampal CA1 cells days after reperfusion. Our results suggest that the regional difference in the induction of HSP70 mRNA may relate to the regional difference of the vulnerability of neuronal cells after transient ischemia.