Fig. 1

Prolonged isoflurane exposure induced dose-dependent toxic effects in cultured astrocytes. a Cell viability was measured with MTT assays following exposure to isoflurane for different hours at 2.4%, and the relative cell viabilities of the experimental groups were normalized to that of the control group (N = 4). b The cell viability was determined with MTT assays following exposure to different doses isoflurane for 9 h (N = 5). c LDH release was quantitatively measured as a biomarker of cellular cytotoxicity and cytolysis, and the relative LDH release levels in the experimental groups were normalized to that of the control group after isoflurane exposure for 9 h (N = 5). d The percentages of TUNEL-positive astrocytes after isoflurane exposure for 9 h are shown (N = 3). e The graphs display representative data from three independent experiments (N = 3). Bar = 200 μm. ISO, isoflurane. The data are presented as the mean ± SEM. ^* P < 0.05, ^** P < 0.01. The P values were determined by one-way ANOVA (a, b, c and d) with correction for multiple comparisons