[CATALITICAL PROPERTIES OF LIVER MONOAMINE OXIDASE IN THE CHUM SALMON ONCORHYNCHUS KETA].

The substrate and inhibitory specificity of mitochondrial monoamine oxidase (MAO) in the liver of males of the summer form of the chum salmon Oncorhynchus keta was studied. As to the spectrum of deaminated substrates, the hepatic MAO of the chum salmon is similar to MAO of most terrestrial mammals, for eight classical MAO substrates similarity in their substrate characteristics were found. Analysis of the antimonoamine oxidase activity of two derivaties of 2-propinilamine, five derivatives of acridine as well as of pyronine G revealed significant qualitative and quantitative differences as compared to the hepatic enzyme of tuna and whitefish.

[SENSITIVITY OF LIVER MONOAMINE OXIDASE IN THE LAMPREY LAMPETRA FLUVIATILIS TO SOME TRICYCLIC COMPOUNDS].

A comparative analysis of the effect of the five acridine, three phenothiazine and one xanten (pyronine G) derivatives on the activity of liver mitochondrial monoamine oxidase (MAO) in sexually mature male river lampreys Lampetra fluviatilis has been conducted. Tyramine, dopamine, serotonin, noradrenaline, benzylamine, β-phenylethylamine and N-methylhistamine have been used as substrates for analyzing the monoamine oxidase activity of heterocyclic compounds. The analyzed synthetic hexamerous tricyclic compounds exhibit irreversible inhibition of the enzyme but no specificity depending on the desaminated substrate.

[Enzymological characteristics of liver monoamine oxidase of the skipjack tuna Katsuwonus pelamis].

There has been carried out a study of substrate and inhibitor specificity of the liver mitochondrial monoamine oxidase (MAO) of the striped-bellied tunny Katsuwonus pelamis. Results of the substrate-inhibitor analysis with use of chlorgilin and deprenyl are an indirect proof for the existence in the tunny liver of one molecular MAO form. The studied enzyme, like the liver MAO of terrestrial mammals, deaminates tyramine, tryptamine, dopamine, serotonin, noradrenalin, benzylamine, β-phenylethylamine, and N-methylhistamine, does not deaminate histamine and is not inhibited by 10 mM semicarbaside.