Inhibition of MAO-B by (-)-deprenyl alters dopamine metabolism in the macaque (Macaca facicularis) brain.
The present study has examined whether MAO-B has a role in DA metabolism in the primate CNS in situ. Eleven macaques (macaca facicularis) were used in this study to examine the effects of (-)-deprenyl (1 mg/kg, i.v., 2 and 24 hours). (-)-Deprenyl administration completely and selectively blocked MAO-B activity and blocked DA metabolism in the caudate nucleus and frontal cortex. DA metabolism in the substantia nigra was not affected by MAO-B inhibition. Changes in DA metabolism were accompanied by changes in 5-hydroxytryptamine (5HT) turnover: 5-hydroxyindole acetic acid (5HIAA) levels increased in the caudate and decreased in the frontal cortex. Levels of 2-phenylethylamine (PE), a putative modulator of dopaminergic transmission, were increased by MAO-B inhibition in all three brain regions examined. It is concluded that in some regions of the primate brain, in contrast to the rat, MAO-B has an important role in DA metabolism.
Paterson
I A
IA
Neuropsychiatric Research Unit, University of Saskatchewan, Saskatoon, Canada.
Davis
B A
BA
Durden
D A
DA
Juorio
A V
AV
Yu
P H
PH
Ivy
G
G
Milgram
W
W
Mendonca
A
A
Wu
P
P
Boulton
A A
AA
D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000187:drug effects* / Q000378:metabolism*; D002421:Caudate Nucleus / Q000187:drug effects / Q000378:metabolism; D004298:Dopamine / Q000378:metabolism*; D005625:Frontal Lobe / Q000187:drug effects / Q000378:metabolism; D006719:Homovanillic Acid / Q000378:metabolism; D006897:Hydroxyindoleacetic Acid / Q000378:metabolism; D008252:Macaca fascicularis; D008995:Monoamine Oxidase / Q000378:metabolism*; D008996:Monoamine Oxidase Inhibitors / Q000494:pharmacology*; D010627:Phenethylamines / Q000378:metabolism; D012642:Selegiline / Q000494:pharmacology*; D012701:Serotonin / Q000378:metabolism
D008996:Monoamine Oxidase Inhibitors; D010627:Phenethylamines; D015102:3,4-Dihydroxyphenylacetic Acid; D012642:Selegiline; C029261:phenethylamine; D012701:Serotonin; D006897:Hydroxyindoleacetic Acid; D008995:Monoamine Oxidase; D004298:Dopamine; D006719:Homovanillic Acid