The deamination of noradrenaline and 5-hydroxytryptamine by rat brain and heart monoamine oxidase and their inhibition by cimoxatone, toloxatone and MD 770222.
In both rat brain and heart, noradrenaline and 5-hydroxytryptamine are metabolised predominantly by monoamine oxidase-A. The Km values for 14C-noradrenaline in the rat brain and heart are 290 microM and 300 microM, respectively, whereas for 14C-5-hydroxytryptamine the values are 180 microM and 140 microM, respectively. In the rat brain, mixed substrate experiments suggested that 14C-noradrenaline and 14C-5-hydroxytryptamine are metabolised at the same active centre. Both substrates are inhibited with similar Ki values by the reversible inhibitors cimoxatone, toloxatone and MD 770222.
D000818:Animals; D001921:Brain / Q000201:enzymology*; D003641:Deamination; D066298:In Vitro Techniques; D007700:Kinetics; D008297:Male; D008928:Mitochondria / Q000378:metabolism; D008995:Monoamine Oxidase / Q000378:metabolism*; D008996:Monoamine Oxidase Inhibitors / Q000494:pharmacology*; D009206:Myocardium / Q000201:enzymology*; D009419:Nerve Tissue Proteins / Q000378:metabolism; D009638:Norepinephrine / Q000378:metabolism*; D010080:Oxazoles / Q000494:pharmacology; D023303:Oxazolidinones; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000378:metabolism*
D008996:Monoamine Oxidase Inhibitors; D009419:Nerve Tissue Proteins; D010080:Oxazoles; D023303:Oxazolidinones; D012701:Serotonin; C010798:toloxatone; C038383:MD 770222; D008995:Monoamine Oxidase; C026234:cimoxatone; D009638:Norepinephrine