Mas-Mediated Antioxidant Effects Restore the Functionality of Angiotensin Converting Enzyme 2-Angiotensin-(1-7)-Mas Axis in Diabetic Rat Carotid

Autor(es)

Pernomian, Larissa ; Gomes, Mayara Santos ; Araujo Restini, Carolina Baraldi ; de Oliveira, Ana Maria

• Tipo de documento: Artigo Científico
• Fonte: BIOMED RESEARCH INTERNATIONAL; v. 2014, p. 20-pg., 2014-01-01.

Resumo

We hypothesized that endothelial AT(1)-activated NAD(P)H oxidase-driven generation of reactive oxygen species during type I-diabetes impairs carotid ACE2-angiotensin-(1-7)-Mas axis functionality, which accounts for the impaired carotid flow in diabetic rats. We also hypothesized that angiotensin-(1-7) chronic treatment of diabetic rats restores carotid ACE2-angiotensin-(1-7)-Mas axis functionality and carotid flow. Relaxant curves for angiotensin II orangiotensin-(1-7) were obtained in carotid from streptozotocin-induced diabetic rats. Superoxide or hydrogen peroxide levels were measured by flow cytometry in carotid endothelial cells. Carotid flow was also determined. We found that endothelial AT1-activated NAD(P) H oxidase-driven generation of superoxide and hydrogen peroxide in diabetic rat carotid impairs ACE2-angiotensin-(1-7)-Mas axis functionality, which reduces carotid flow. In this mechanism, hydrogen peroxide derived from superoxide dismutation inhibits ACE2 activity in generating angiotensin-(1-7) seemingly by activating.. Cl, SWELL, while superoxide inhibits the nitrergic Mas-mediated vasorelaxation evoked by angiotensin-(1-7). Angiotensin-(1-7) treatment of diabetic rats restored carotid ACE2-angiotensin-(1-7)-Mas axis functionality by triggering a positive feedback played by endothelial Mas receptors, that blunts endothelial AT1-activated NAD(P)H oxidase-driven generation of reactive oxygen species. Mas-mediated antioxidant effects also restored diabetic rat carotid flow, pointing to the contribution of ACE2-angiotensin-(1-7)-Mas axis in maintaining carotid flow. (AU)

• Processo FAPESP: 12/09019-3 - Consequências da dislipidemia sobre os eixos ECA - Ang II - AT1 e ECA2 - Ang-(1-7) - mas do sistema angiotensinérgico em aorta de camundongos LDLr knockout jovens e adultos
• Beneficiário: Ana Maria de Oliveira
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 12/00640-7 - Estudo das consequências do processo inflamatório induzido por receptores AT1 durante aterosclerose sobre o eixo ECA2 - angiotensina-(1-7) -Mas em aorta de camundongo e da participação de receptores Mas nos efeitos vaso- e ateroprotetores de losartan
• Beneficiário: Larissa Pernomian
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 09/01005-0 - Influência do estresse oxidativo sobre a resposta à angiotensina II em carótida contra-lateral à lesão por catéter-balão de rato diabético
• Beneficiário: Larissa Pernomian
• Modalidade de apoio: Bolsas no Brasil - Doutorado