Fig. 5. Effects of sevoflurane on the carbachol (ED⁸⁰)–enhanced airway muscle tone and increased intracellular concentration of free Ca²⁺([Ca²⁺]ⁱ) in control (cigarette-sham), ovalbumin-sensitized, and chronic cigarette-smoking groups. Data are expressed as mean ± SD (n = 6 each). *  P < 0.05  versus each control value without sevoflurane. †  P < 0.05  versus the values in other groups. MAC = minimum alveolar concentration. Similar to the data obtained for respiratory function parameters, in both the control and ovalbumin-sensitized groups, sevoflurane significantly and substantially inhibited muscle tension, concomitant with a decrease in [Ca²⁺]ⁱin a dose-dependent manner. The anesthetic had a rather smaller but significant inhibitory effect on both muscle tension and [Ca²⁺]ⁱin the chronic cigarette-smoking group.