The density of monoamine oxidase B sites is not altered in the postmortem brain of alcoholics.
The status of the enzyme monoamine oxidase B (MAO-B) was directly evaluated in the postmortem brain from 20 alcoholics and 23 matched controls. The density of MAO-B sites was quantified by the specific binding of the selective inhibitor [3H]Ro 19-6327 (lazabemide) (8 nM) to cortical membranes. A positive correlation between age at death and MAO-B density was observed in the total sample (r = 0.37, p = 0.015). The density of MAO-B in alcoholics (Bmax = 1,263 +/- 131 fmol/mg of protein) was not different form that in control (Bmax = 1,131 +/- 96 fmol/mg of protein). Ethanol in vitro inhibited [3H]Ro 19-6327 binding, with similar potency in membranes form alcoholics (Ki = 280 +/- 13 mM) and controls (Ki = 338 +/- 84 mM). The present results in brain tissue contrast with previous reports of decreased MAO-B enzymatic activity in platelets of alcoholics, but strongly agree with recent genetic studies on MAO-B status in alcoholism.
Maeztu
A I
AI
Department of Pharmacology, University of the Basque Country, Leioa, Bizkaia, Spain.
Ballesteros
J
J
Callado
L F
LF
Gutiérrez
M
M
Meana
J J
JJ
D000328:Adult; D000368:Aged; D000437:Alcoholism / Q000235:genetics / Q000473:pathology*; D002540:Cerebral Cortex / Q000473:pathology*; D005260:Female; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D008995:Monoamine Oxidase / Q000235:genetics / Q000502:physiology*; D008996:Monoamine Oxidase Inhibitors / Q000493:pharmacokinetics; D010848:Picolinic Acids / Q000493:pharmacokinetics
D008996:Monoamine Oxidase Inhibitors; D010848:Picolinic Acids; C059303:lazabemide; D008995:Monoamine Oxidase