Monoamine oxidase and semicarbazide-sensitive amine oxidase kinetic analysis in mesenteric arteries of patients with type 2 diabetes

• Published in: Physiological research Vol. 60; no. 2; pp. 309 - 315
• Main Authors: Nunes, S F, Figueiredo, I V, Pereira, J S, de Lemos, E T, Reis, F, Teixeira, F, Caramona, M M
• Format: Journal Article
• Language: English
• Published: Czech Republic Institute of Physiology 01.01.2011
• Subjects: Aged; Amine Oxidase (Copper-Containing) - analysis; Amine Oxidase (Copper-Containing) - metabolism; Diabetes; Diabetes Mellitus, Type 2 - enzymology; Dopamine; Enzymes; Female; Free radicals; Humans; Kinetics; Male; Mesenteric Arteries - enzymology; Middle Aged; Monoamine Oxidase - analysis; Monoamine Oxidase - metabolism; Norepinephrine - metabolism; Pathogenesis; Rodents; Serotonin; Studies; Surgery; Veins & arteries
• ISSN: 0862-8408; 1802-9973
• DOI: 10.33549/physiolres.931982

Monoamine oxidase (MAO, type A and B) and semicarbazide-sensitive amine oxidase (SSAO) metabolize biogenic amines, however, the impact of these enzymes in arteries from patients with type 2 diabetes remains poorly understood. We investigated the kinetic parameters of the enzymes to establish putative correlations with noradrenaline (NA) content and patient age in human mesenteric arteries from type 2 diabetic patients. The kinetic parameters were evaluated by radiochemical assay and NA content by high-performance liquid chromatography (HPLC). The activity of MAO-A and SSAO in type 2 diabetic vascular tissues was significantly lower compared to the activity obtained in non-diabetic tissues. In the correlation between MAO-A (K(m)) and NA content, we found a positive correlation for both the diabetic and non-diabetic group, but no correlation was established for patient age. In both groups, MAO-B (V(max)) showed a negative correlation with age. The results show that MAO-A and SSAO activities and NA content of type 2 diabetic tissues are lower compared to the non-diabetic tissues, while MAO-B activity remained unchanged. These remarks suggest that MAO-A and SSAO may play an important role in vascular tissue as well as in the vascular pathophysiology of type 2 diabetes.