Modification of L-DOPA pharmacological activity by MAO inhibitors.
Dopamine behaves mainly as a MAO-A substrate in rodent brain, but selective inhibition of MAO-B results in an increased turning activity following L-DOPA administration in hemi-Parkinsonian rodents. Unilateral substantia nigra dopaminergic denervation results in serotonergic hyper-innervation which may increase the contribution of MAO-A in the denervated striatum. Possibly as a result of this, there was no change in striatal MAO-A activity when 95% of dopaminergic innervation was reduced by 6-hydroxydopamine, as assessed by apomorphine-induced turning activity. MAO-B as well as MAO-A may contribute to deamination of dopamine produced from L-DOPA.
Finberg
J P M
JP
Pharmacology Department, Rappaport Faculty of Medicine, Technion, Haifa, Israel. finberg@tx.technion.ac.il
Sader-Mazbar
O
O
D000818:Animals; D001479:Basal Ganglia / Q000187:drug effects / Q000201:enzymology / Q000503:physiopathology; D001921:Brain / Q000187:drug effects* / Q000201:enzymology* / Q000503:physiopathology; D003714:Denervation; D004298:Dopamine / Q000378:metabolism; D004347:Drug Interactions; D007980:Levodopa / Q000494:pharmacology*; D008995:Monoamine Oxidase / Q000187:drug effects / Q000378:metabolism; D008996:Monoamine Oxidase Inhibitors / Q000494:pharmacology*; D009434:Neural Pathways / Q000187:drug effects / Q000201:enzymology / Q000503:physiopathology; D016627:Oxidopamine; D020734:Parkinsonian Disorders / Q000188:drug therapy* / Q000201:enzymology* / Q000503:physiopathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012701:Serotonin / Q000378:metabolism; D013378:Substantia Nigra / Q000187:drug effects / Q000201:enzymology / Q000503:physiopathology; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology
D008996:Monoamine Oxidase Inhibitors; D012701:Serotonin; D007980:Levodopa; D016627:Oxidopamine; D008995:Monoamine Oxidase; D004298:Dopamine