This Article  • References  • Full text PDF  • Reply to article  • Send to a friend  • Save in My Folder  • Save to citation manager  • Permissions  Citing Articles  • Citation map  • Citing articles on HighWire  • Contact me when this article is cited  Related Content  • Similar articles in this journal  Social Bookmarking   What's this?

Evaluation Using a Peripheral Decarboxylase Inhibitor

Paul E. Garfinkel, MD; Jerry J. Warsh, MD, PhD; Harvey C. Stancer, MD, PhD; Damodar D. Godse, PhD

Arch Gen Psychiatry. 1977;34(6):735-739.

Abstract
• Carbidopa, a decarboxylase inhibitor that does not cross the blood-brain barrier, inhibits the peripheral synthesis of noradrenaline, serotonin, and tryptamine. By reducing the peripheral component of end-products of these amines in urine, a more accurate assessment of central nervous system (CNS) amine metabolism is provided. Urinary 5-hydroxyindoleacetic acid (5-HIAA), tryptamine, and 3-methoxy-4-hydroxyphenylglycol (MHPG) were measured over ten days in ten normal controls and eight bipolar depressives. After a three-day baseline period, carbidopa, 100 mg three times a day, was given for seven days. While the patients tended to excrete less MHPG in the baseline period, these differences became somewhat larger, and statistically significant when peripheral contributions were reduced with carbidopa. While carbidopa resulted in striking inhibition of tryptamine excretion, and smaller decreases in the excretion of 5-HIAA and MHPG, evidently from storage pools, there were no significant differences in degree of inhibition between patients and controls. Absolute values of 5-HIAA and tryptamine were similar for both groups, during the baseline and again with carbidopa. These results after carbidopa are compatible with a central catecholaminergic deficit in bipolar depressives and the use of urinary MHPG as an index of CNS catecholamine function.

Author Affiliations
From the Department of Psychiatry, Clarke Institute of Psychiatry, University of Toronto.

Footnotes
Accepted for publication Dec 7, 1976.

Reprint requests to Department of Psychiatry, Clarke Institute of Psychiatry, 250 College St, Toronto, Canada M5T 1R8 (Dr Garfinkel).

CiteULike    Connotea    Del.icio.us    Digg    Reddit    Technorati     What's this?

THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES

Afternoon Continuous Plasma Levels of 3-Methoxy-4-hydroxyphenylglycol and Age: Distinctive Biologic Subgroups of Endogenous Depression?
Halbreich et al.
Arch Gen Psychiatry 1987;44:804-812.
ABSTRACT  

Five Antidepressant Treatments in Depressed Patients: Effects on Urinary Serotonin and 5-Hydroxyindoleacetic Acid Output
Linnoila et al.
Arch Gen Psychiatry 1984;41:688-692.
ABSTRACT  

Plasma Free and Conjugated MHPG in Psychiatric Patients: A Pilot Study
Sweeney et al.
Arch Gen Psychiatry 1980;37:1100-1103.
ABSTRACT  

Primary Affective Disorder, Clinical State Change, and MHPG Excretion: A Longitudinal Study
Pickar et al.
Arch Gen Psychiatry 1978;35:1378-1383.
ABSTRACT  

Clinical and Biochemical Heterogeneity of Depressive Disorders
MAAS
ANN INTERN MED 1978;88:556-563.
ABSTRACT