Plasma 3,4-dihydroxyphenylethyleneglycol and 3-methoxy-4-hydroxyphenylethyleneglycol as indicators of central noradrenergic activity. A comparative study on control subjects and depressed patients.

Animal studies have suggested interspecies differences in brain norepinephrine (NE) metabolism, especially with regard to the relative proportions of 3,4-dihydroxyphenylethyleneglycol (DOPEG) compared to 3-methoxy-4-hydroxyphenylethyleneglycol (MOPEG). In order to question the value of both glycol metabolites as peripheral indices of central noradrenergic activity, a comparative study of plasma DOPEG and MOPEG (measured by HPLC) related to depression, sex, age and diagnostic categories (DSM-III) was carried out on depressed and control subjects. In addition, two groups of 8 patients were randomly submitted to a desipramine 150 mg/day, or a metapramine 450 mg/day antidepressant treatment influencing the formation of DOPEG and MOPEG in a different way. The study did not demonstrate any difference between DOPEG and MOPEG for most of the experimental factors. We found also a significant positive correlation between plasma levels of DOPEG and MOPEG. Our results support the idea that each of these two biological indices can be used in the assessment of central noradrenergic activity.