3-5-diethoxy-4-aminomethylpyridine and carbamylhydrazine

A semicarbazide-sensitive amine oxidase with affinity for benzylamine (Bz.SSAO) was found in the human heart. This enzymatic activity has a K(m) of 278 +/- 35.3 microM and a V(m) of 114.7 +/- 14.7 nmol mg-1 min-1 (mean +/- SE of eight hearts) for benzylamine and is strongly inhibited by 1 mM histamine and by B24, a specific inhibitor of Bz.SSAO. No diamine oxidase activity was found in the human heart. The levels of MAo and B were assayed: MAO A showed a K(m) of 137.1 +/- 16.2 microM and a V(m) of 10.4 +/- 2.5 nmol mg-1 min-1 for serotonin; MAo B had a K(m) of 9.9 +/- 1.6 microM and V(m) of 4.3 +/- 1.1 nmol mg-1 min-1 for beta-phenylethylamine (mean +/- SE of seven hearts). The human heart has high MAO B activity and Bz.SSAO with histaminase activity.

Topics: Adult; Aging; Amine Oxidase (Copper-Containing); Amines; Benzylamine Oxidase; Benzylamines; Binding, Competitive; Cardiomyopathies; Enzyme Inhibitors; Female; Histamine; Humans; Kinetics; Male; Middle Aged; Monoamine Oxidase; Myocardium; Putrescine; Pyridines; Semicarbazides

Lung, heart tissues and blood plasma of guinea pigs were investigated to see if tissue-bound semicarbazide-sensitive amine oxidase activities with a high affinity for benzylamine (Bz.SSAO) were present in this species as well as in others. This paper shows that these enzymic activities are present in guinea pig lung and heart where they are mainly localized in the cytosol and in microsomal fraction. These activities have a high affinity for benzylamine and appear unable to oxidize histamine at an appreciable rate in agreement with the observation that the purified Bz.SSAO of guinea pig skin shows weak histaminase activity. These guinea pig Bz.SSAO activities show some homology with the pure pig plasma benzylamine oxidase. They crossreact with the antibodies raised in the rabbit against the pig plasma enzyme. Benzylamine oxidase activity was also found in guinea pig blood plasma.

Topics: Amine Oxidase (Copper-Containing); Animals; Benzylamine Oxidase; Enzyme Inhibitors; Guinea Pigs; Immunohistochemistry; Kinetics; Lung; Male; Myocardium; Oxidoreductases Acting on CH-NH Group Donors; Pyridines; Rabbits; Semicarbazides; Subcellular Fractions; Tissue Distribution

A semicarbazide-sensitive amine oxidase activity with a high affinity for benzylamine (Bz.SSAO) (E.C. 1.4.3.6) is present in guinea pig dorsal skin. This enzymic activity oxidized benzylamine, histamine, 1,4-methylhistamine and acetylputrescine and was inhibited by semicarbazide and by B24 (3,5-diethoxy-4-aminomethylpyridine), a selective inhibitor of Bz.SSAO enzymes. It cross reacted with the antibodies raised against pure pig plasma benzylamine oxidase. Immunohistochemistry showed that it was localized in fibroblasts. Bz.SSAO activity of guinea pig dorsal skin increased during the process of skin healing. A treatment of the wounds with 3 micrograms of b-FGF significantly accelerated the process of skin healing and the increase of Bz.SSAO activity.

Topics: Amine Oxidase (Copper-Containing); Animals; Fibroblast Growth Factor 2; Guinea Pigs; Immunohistochemistry; Male; Molecular Weight; Oxidoreductases Acting on CH-NH Group Donors; Pyridines; Semicarbazides; Skin; Substrate Specificity; Wound Healing