title: Inhibition by Zn(2+) of A-form monoamine oxidase in monkey brain mitochondria.
abstract: The effects of ZnSO(4) on mitochondrial monoamine oxidase (MAO) activity in monkey brain were compared with those in rat and rabbit, in vitro. After preincubation at 25 degrees C for 20 min with 1 microM ZnSO(4), MAO-A activity in monkey brain was about 50% using serotonin (5-HT) as a substrate, and the inhibition was proportional to the concentration of ZnSO(4). However, ZnSO(4) had no effect on MAO-B activity in monkey brain using beta-phenylethylamine (beta-PEA) as a substrate. The inhibition by ZnSO(4) of MAO-A activity was competitive and reversible. CdSO(4) also inhibits MAO-A, but not MAO-B in monkey brain mitochondria. ZnSO(4) did not inhibit either MAO-A or MAO-B activity in rat and rabbit brain mitochondria. These results indicate that the inhibiting action of Zn(2+) differs depending on animal species. In monkey brain mitochondria, MAO-A was highly sensitive to Zn(2+) and MAO-B was less sensitive. These results also suggest that Zn(2+) may regulate the level of catecholamine content in monkey brain.
authors.affiliation: Department of Pharmacology, Oita Medical University, Japan. egacy@oita-med.ac.jp
authors.forename: Toru
authors.initials: T
authors.lastname: Egashira
authors.forename: Fusako
authors.initials: F
authors.lastname: Takayama
authors.forename: Kumiko
authors.initials: K
authors.lastname: Sakai
mesh_terms: D000818:Animals; D001921:Brain / Q000187:drug effects* / Q000648:ultrastructure; D006801:Humans; D008099:Liver / Q000187:drug effects / Q000201:enzymology; D008251:Macaca; D008297:Male; D008928:Mitochondria / Q000187:drug effects* / Q000201:enzymology; D008995:Monoamine Oxidase / Q000378:metabolism*; D008996:Monoamine Oxidase Inhibitors / Q000494:pharmacology*; D010920:Placenta / Q000187:drug effects / Q000201:enzymology; D011817:Rabbits; D051381:Rats; D017208:Rats, Wistar; D013045:Species Specificity; D019287:Zinc Sulfate / Q000494:pharmacology*
chemical_list: D008996:Monoamine Oxidase Inhibitors; D019287:Zinc Sulfate; D008995:Monoamine Oxidase