Abstract
After norepinephrine (NE) is deaminated by monoamine oxidase (MAO), the aldehyde formed is either metabolized to 3,4-dihydroxymandelic acid (DHMA) by aldehyde dehydrogenase or is converted to 3,4-dihydroxyphenylglycol (DHPG) by aldehyde or aldose reductase. The present study examined the effects of inhibition of aldehyde and aldose reductase on production of DHPG and DHMA in rats. Mean (± S.E.) baseline plasma concentrations of DHPG (4.73 ± 0.21 pmol/ml) were 60-fold higher than those of DHMA 0.08 ± 0.01 pmol/ml). Inhibition of aldose and aldehyde reductase reduced plasma DHPG concentrations to 1.88 ± 0.14 pmol/ml and increased plasma DHMA to 4.43 ± 0.29 pmol/ml; additional inhibition of MAO reduced plasma DHPG to 0.16 ± 0.06 pmol/ml and DHMA to 0.19 ± 0.02 pmol/ml. Inhibition of aldehyde and aldose reductase also increased brain tissue levels of DHMA from 8 ± 2 to 384 ± 47 pmol/g and decreased levels of DHPG from 70 ± 9 to 44 ± 5 pmol/g. The results show that DHMA is normally a minor metabolite of NE, but becomes a major metabolite after aldehyde/aldose reductase inhibition.
Original language | English (US) |
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Pages (from-to) | 145-148 |
Number of pages | 4 |
Journal | Journal of the Autonomic Nervous System |
Volume | 66 |
Issue number | 3 |
DOIs | |
State | Published - Oct 13 1997 |
Externally published | Yes |
Keywords
- 3,4-Dihydroxymandelic acid
- 3,4-Dihydroxyphenylglycol
- Aldehyde reductase
- Monoamine oxidase
- Norepinephrine
- Sympathetic nervous system
ASJC Scopus subject areas
- General Neuroscience
- Physiology
- Clinical Neurology