Figure 1. The concentration-related effects of inhaled isoflurane and sevoflurane on the diameters of pial arterioles (large arteriole [>or= to 100 [micro sign]m]; small arteriole [< 100 [micro sign]m]) in 24 dogs. Data are expressed as percentage changes in diameter. Isoflurane and sevoflurane significantly dilated both large and small pial arterioles in a concentration-dependent manner. Glibenclamide attenuated such vasodilations (difference not significant in isoflurane). Values are expressed as mean +/− SD (n = 12 for each column). *P < 0.05 for comparisons between indicated values. NS = not significant.[dagger] P < 0.05 compared with the corresponding 0.5 minimum alveolar concentration value.[section] P < 0.05 compared with the corresponding 1 minimum alveolar concentration value.