Fig. 16
Effects of preconditioning on Gz-induced cerebral hypoperfusion. Two weeks before the acceleration stress of +3.0 Gz for 30 s, rats (n = 8) were exposed to repeated lighter Gz acceleration stress (+1.5 Gz for 15 min, three times per day, one of 2 days, five cycles). Three days later after the conditioning, the effects of +3.0 Gz acceleration for 30 s on arterial pressure at the level of the brain (brain AP) and brain-tissue oxygen concentration (tissue PO2) were measured in the conditioned rats (Pre-conditioned, n = 8), and compared to those in non-conditioned control rats (non-conditioned, n = 8). Each of 8-rat data were presented. *p < 0.05 by one-factor ANOVA with the Tukey–Kramer test. The decreasing rate (Slope decrease/s) in PO2 of the hippocampus during 30 s of +3.0 Gz did not show any significant difference, whereas the slope in APLB and PO2 of the cortex during the 30 s showed significant differences between conditioned and control rats [26, 29, 37]