the relationship between the concentrations of imi or its active metabolites in plasma or brain and the extracellular availability of cerebral norepinephrine was also studied and found to be nonlinear : the concentration of norepinephrine in the cerebroventricular fluid approached a maximal value when the combined concentration of imi and its metabolites was 10 micrograms/g in the brain or 1.5 micrograms/ml in plasma .
C0086045
concentration
C0006104
brain