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

• Autor(a) principal: Nunes, S. F.
• Data de Publicação: 2011
• Outros Autores: Figueiredo, I. V., Pereira, João, Lemos, E. T., Reis, F., Teixeira, F., Caramona, M. M.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10316/102755; https://doi.org/10.33549/physiolres.931982
• topic: Human mesenteric arteries; Monoamine oxidase; Semicarbazide-sensitive amine oxidase; Type 2 diabetes; Noradrenaline content; Aged; Amine Oxidase (Copper-Containing); Diabetes Mellitus, Type 2; Female; Humans; Kinetics; Male; Mesenteric Arteries; Middle Aged; Monoamine Oxidase; Norepinephrine

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.