Fig. 4. Kinetics of adenosine induction after ketamine administration. ( A ) Saline or ketamine (10 mg/kg) was injected subcutaneous to a rat. At each time point, the same animal was bled by heart puncture for adenosine determination. ( B ) Saline or ketamine (10 mg/kg) was injected subcutaneously with or without an intraperitoneal inoculation of a lethal dose of E. coli (3 × 107colony-forming units) to CD1 mice or injected with saline. After treatment CD1 mice were bled by heart puncture and killed (n = 3 for each time point), ( C ) saline or ketamine (10 mg/kg) was injected subcutaneously. After treatment at the indicated time points, mice were killed, and peritoneal lavage was performed (n = 3 for each time point). Adenosine concentrations in sera and lavage fluids were determined by high-performance liquid chromatography as described in figure 3 . * P < 0.05 for ketamine treatment compared with time 0. P < 0.05 for ketamine plus E. coli treatment compared with time 0. Each graph in the figure depicts a representative experiment out of three performed.
