Fig. 2. (A ) Percentage of young and aged rats with no movement for sevoflurane. Each point represents n = 12 rats. Curves were fitted using sigmoidal concentration-response analysis. The minimum alveolar concentration (MAC) for young adult and aged rats with 95% CI (horizontal bars ) is shown. (B ) Percentage sevoflurane required in young and aged rats to produce anesthesia over 4 h. Data are mean values of sevoflurane concentration in the anesthetic chamber in two consecutive experimental groups for each age group. n = 10 young rats and n = 7 aged rats. Superimposed on these curves are the 95% CIs from the MAC determination from A , Red dashed lines and blue dashed lines are the 95% CIs for young and aged rats, respectively. Error bars are obscured by the symbols. (C ) Systolic (closed symbols ) and diastolic (open symbols ) blood pressure in young and aged sevoflurane-anesthetized rats. Data are mean ± SEM. n = 10 per treatment group in young rats and n = 7 in aged rats.