C-FOS AND HSP70 GENE-EXPRESSION IN RAT BRAINS IN HIGH GRAVITATION-INDUCED CEREBRAL-ISCHEMIA

Previous studies have shown that brief exposures of rodents to high gr avitation forces (+G(z)) in a specifically designed centrifuge cause g lobal cerebral ischemia. In the present study, the effect of +G(z) exp osure to +22.5G(z) for 15 to 60 s on c-fos and HSP70 gene expression w as examined. Northern and RT-PCR analyses of total RNA isolated from b rains of rats at different post-exposure times revealed a significant, time-dependent increase in the c-fos mRNA level which returned to nea r normal by 180 min. The HSP70 mRNA level was increased two-fold at 30 min post exposure, and remained elevated until 180 min. The transient stimulation of c-fos and HSP70 gene expression should serve as useful biomarkers for hypergravic stress on the brain. The present results s hould aid in design of future experiments in our understanding of the pathophysiology of the high +G(z) challenges.