Lithium Treatment Increases Norepinephrine Turnover in the Plasma of Healthy Subjects

To the Editor.—  Manji and associates¹ reported that 2 weeks of treatment with lithium enhanced norepinephrine (NE) levels in plasma and urinary NE and normetanephrine (NMN) excretion in normal subjects, while 1 week of treatment with lithium did not. These temporally specific effects of lithium treatment on NE turnover have been suggested to be connected to desensitization of presynaptic-2— adrenergic receptors in peripheral sympathetic nerves.We confirm these results and specify the temporal action of lithium salts on plasma NE turnover. Our study in healthy volunteers compared levels of dihydroxyphenylethyleneglycol (DOPEG), the main deaminated metabolite of NE in the central nervous system, in plasma before, during, and after 20 days of lithium treatment. We administered lithium carbonate during 20 days to seven volunteers (five men and two women aged 30 to 40 years) in good health from whom informed consent was obtained. Lithium was administered at 9 AM