Fig. 4. The time course histogram of the percentages of early apoptotic lymphocytes after 6, 12, and 24 h of exposure to 1.5-mm inhalation anesthetics. Data are expressed as mean ± SD. The percentages of early apoptotic lymhocytes in all the groups were significantly higher than that at one previous time point (P < 0.01) and significantly higher in the isoflurane group, followed by the sevoflurane group and the control group in descending order at the 12- and the 24-h time points (P < 0.01). There were no significant differences among the groups at the 6-h time point. n = 12 per group.