Differences between monoamine oxidase concentrations in striatum and forebrain of aged and young rats.
The MAO-A and MAO-B activities in the striatum and the rest of the forebrain of young adult and aged rats were determined and compared. There was no significant difference in Km values of MAO-A for 5-HT or of -B for benzylamine in any of the brain regions of both rat groups. With increase in age, the Vmax value of MAO-A in the forebrain decreased; in the striatum the Vmax values of MAO-A and -B increased with age. The MAO-A concentrations, measured by enzyme titration with clorgyline or 1-deprenyl as the titre, were the same in both brain regions of young and aged rats, but in both brain regions of aged rats, MAO-B concentrations were greater than those in young rats. The MAO-B concentrations increased in parallel with the increases in Vmax indicating that the increase with age was due to increase in the number of MAO molecules.
Arai
Y
Y
Department of Pharmacology, School of Medicine, Showa University, Tokyo, Japan.
Kinemuchi
H
H
D000375:Aging / Q000378:metabolism*; D000818:Animals; D001596:Benzylamines / Q000378:metabolism; D003010:Clorgyline / Q000494:pharmacology; D003342:Corpus Striatum / Q000201:enzymology*; D005625:Frontal Lobe / Q000201:enzymology*; D007700:Kinetics; D008297:Male; D008995:Monoamine Oxidase / Q000032:analysis*; D008996:Monoamine Oxidase Inhibitors / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000378:metabolism
D001596:Benzylamines; D008996:Monoamine Oxidase Inhibitors; D012701:Serotonin; C030796:benzylamine; D008995:Monoamine Oxidase; D003010:Clorgyline