Estudo dos efeitos de hipoglicemiantes orais na reatividade vascular adrenérgica, no escape renovascular e na taquifilaxia em rins isolados de coelho

• Ano de defesa: 2017
• Autor(a) principal: Menezes, Antonio Teles de
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Palavras-chave em Português: Endoleak; Taquifilaxia; Reatividade-Estabilidade; Hipoglicemiantes
• Link de acesso: http://www.repositorio.ufc.br/handle/riufc/24130

Vascular escape is defined as the inability of the arterial smooth muscle to remain contracted, completely or partially, when a constant vasoconstrictor stimulus occurs, such as occurs during the infusion of adrenergic agonists (noradrenaline, phenylephrine, etc.). The vascular escape appears to have a special meaning as a protective mechanism against sudden and frequent variations in vascular tone. The mechanisms involved in rapidly tachyphylaxis have been extensively studied in molecular terms, especially for G protein coupled receptors. The aim of this study was to evaluate the effects of metformin, glimepiride and glibenclamide on the renovascular escape of isolated rabbit kidney in normal animals, their blood pressure responses in perfusate flow, urinary flow, vascular resistance and reactivity. Protocols with open system of isolated and perfused kidney, as well as of aorta rings were used to study these events. The infusion of the three oral antidiabetic drugs in Krebs-Henseleit solution showed an increase in perfusion pressure compared to the control group (KH: 25.46 ± 3.63 mmHg; MET + KH: 58.19 ± 5.49 mmHg; GLIM + KH: 63.91 ± 7.80 mmHg, GLIB + KH: 102.27 ± 13.28 mmHg), noting that glibenclamide obtained an upward pressure curve, and all parameters of perfusate, urinary flow and vascular resistance were significantly altered. In infusions with phenylephrine, in three curves, changes in perfusion pressures were observed (KH + PHE: 117.31 ± 12.24 mmHg; MET + PHE: 111.68 ± 8.62 mmHg; GLIM + PHE: 102.91 ± 11 , As well as the presence of vascular escape where they were statistically different in the pressure curves (KH + PHE: 15, 28, 28, 28, 28, 19 ± 3.09%, MET + PHE: 23.45 ± 3.70%, GLIM + PHE: 38.88 ± 5.15%, GLIB + PHE: 34.11 ± 6.28%). The confirmation of the participation of endothelin by tezosentan blockade and subsequent infusion with glibenclamide (TEZO+GLIB: 91.42 ± 4.93 mmHg), and the potentiation of pressure effects in aortic rings was evident in this study when glimepiride and metformin were infused (PHE + MET: 0.97 ± 0.03g; PHE + GLIM: 1.45 ± 0.07g). Therefore, the research revealed the existence of strong pharmacological interaction of oral antidiabetic drugs in perfused kidney, as well as in rabbit aorta rings, characterizing significant potentiation of α1-adrenergic responses in renovascular escape and tachyphylaxis.