Hypoxic tolerance induction in rat brain slices following hypoxic preconditioning due to expression of neuroprotective proteins as revealed by dynamic changes in glucose metabolism

We prepared rat brain slices following sublethal hypoxic pretreatment (preconditioning) and untreated (control) rats, and measured the cerebral glucose metabolic rate (CMRglc) by dynamic positron autoradiography with [F-18]2-fluoro-2-deoxy-D-glucose before and after originally lethal 20-min hypoxic loading. In the regions of interest such as the frontal cortex, the CMRgIc before hypoxic loading did not differ between the preconditioning and control groups. The CMRgIc after reoxygenation was markedly lower than that before hypoxic loading in the control group but did not significantly differ from the preloading value in the preconditioning group. Thus, hypoxic tolerance induction by preconditioning was demonstrated using the maintenance of CMRgIc as a neuronal viability index. In addition, profiling of gene expression using an Atlas Rat Stress Array suggested the involvement of the expression of genes such as stress protein in hypoxic tolerance induction. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.