Figure 4. The mean (SD) levels of (A) plasma epinephrine, (B) norepinephrine, and (C) 3,4-dihydroxyphenylglycol (DHPG) in part 2 of the study (n = 8). Dexmedetomidine (2.5 [micro sign]g/kg) was administered intramuscularly at time 0 followed by intravenous placebo or atipamezole (15, 50, and 150 [micro sign]g/kg) infusion at 60 - 62 min (indicated by an arrow). Most error bars have been omitted for clarity.