The effect of deprenyl (selegiline) on intra- and extraneuronal dopamine oxidation.
It was found that in the rat striatum DA was oxidized extrasynaptosomally to 11% by MAO-A and to 3% by MAO-B. The corresponding intrasynaptosomal oxidations were 84% and 2%, respectively. Those figures were virtually unchanged even if the rat brain MAO-B was selectively inhibited to 87% by deprenyl. In the human brain extrasynaptosomal oxidation was 16% and 66%, respectively, by MAO-A and -B. Intrasynaptosomally the corresponding figures were 12% and 6%, respectively. Selective inhibition of human caudate MAO-B was calculated to give a total reduction of DA oxidation of 63%. The differences between man and rat are due to the proportionately greater oxidation of DA by MAO-B in man, which is a consequence of a higher ratio of concentration of MAO-A/-B in the rat.
D000818:Animals; D001921:Brain / Q000378:metabolism*; D004298:Dopamine / Q000378:metabolism*; D006801:Humans; D008995:Monoamine Oxidase / Q000378:metabolism; D008996:Monoamine Oxidase Inhibitors / Q000494:pharmacology; D009474:Neurons / Q000378:metabolism; D010084:Oxidation-Reduction; D010627:Phenethylamines / Q000494:pharmacology*; D051381:Rats; D012642:Selegiline / Q000494:pharmacology*; D013574:Synaptosomes / Q000378:metabolism; D014018:Tissue Distribution
D008996:Monoamine Oxidase Inhibitors; D010627:Phenethylamines; D012642:Selegiline; D008995:Monoamine Oxidase; D004298:Dopamine