Figure 3. Concentration-response curves for the effects of increasing end-tidal concentrations of inhalational anesthetics on spontaneous renal sympathetic nerve activity. (Top) Desflurane. (Middle) Isoflurane. (Bottom) Halothane. Values expressed as percentage of control, mean (SD, n = 5) in each group. Off indicates values following withdrawal of each agent. Recovery to within control values occurred at 60 min and 30 min for desflurane and isoflurane, respectively. There were no statistically significant changes in response to either the administration or withdrawal of halothane. Asterisks indicate within-group comparison with control:*P < 0.02, **P < 0.01, ***P < 0.001.