O Wortmannin reverte a hiporreatividade de aortas à fenilefrina associada à fase final da prenhez de ratas espontaneamente hipertensas (SHR)

• Autor(a) principal: Santos, Dalise Zancheta dos [UNESP]
• Data de Publicação: 2014
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/124060; http://www.athena.biblioteca.unesp.br/exlibris/bd/cathedra/25-05-2015/000831217.pdf
• topic: Aorta; Prenhez; Fenilefrina; Ratos endogâmicos SHR; Pregnancy, Animal

Normotensive or hypertensive pregnant rats (SHR) show a significant reduction in blood pressure in the final period of pregnancy, associated with reduced activity of perivascular sympathetic mesenteric beds and reduced vasoconstrictor responses to some vasoconstrictor agonists. The vascular endothelium modulates contractile response stimulated by vasoconstrictors and in pregnancy, an additional modulation of nitric oxide (NO) on vascular reactivity of aortas has been attributed to increased activity of endothelial nitric oxide synthase (eNOS). However, no change in the aortas of reactivity to acetylcholine or A23187 was observed in aortas of pregnant rats. The involvement of a signaling pathway independent of receptor activation and less dependent calcium was suggested. This pathway is involved in the modulation of endothelial vasoconstriction during pregnancy. The expression of phosphorylated eNOS is increased in the aorta of pregnant rats and this enzyme can be phosphorylated on serine and threonine residues of the PI3K/Akt pathway. However, the participation of the PI3K/AKT/eNOS pathway in hyporeactivity in the aortas of pregnant rats to phenylephrine has not been demonstrated. The aim of this study was evaluate if the PI3K/AKT pathway inhibitor (Wortmannin) could reverse the hyporeactivity of aortas to phenylephrine associated with the end of pregnancy and change the cytosolic concentrations of nitric oxide (NO), calcium (Ca2+) and reactive oxygen species (ROS) in isolated endothelial cells from aortas of pregnant Wistar rats and SHR. Initially, we evaluated the possible changes in cardiovascular parameters and baroreflex sensitivity associated with pregnancy in spontaneously hypertensive rats (SHR) by in vivo studies. The effect of Wortmannin was evaluated in the isolated aortas reactivity to phenylephrine and by functional studies through cytosolic concentrations of NO, Ca2+ and ROS...