UFES

Please use this identifier to cite or link to this item: http://repositorio.ufes.br/handle/10/606
Title: Effects of ouabain on vascular reactivity
Authors: Vassallo, Dalton Valentim
Songu-Mize, E.
Rossoni, Luciana Venturini
Amaral, S. M. C.
Keywords: Ouabaína;Hipertensão;Pressão arterial;Fenilefrina;Ratos;Ouabain;Hypertension;Blood Pressure;Phenylephrine;Rats;Rat tail vascular bed perfusion;Vascular reactivity
Issue Date: Apr-1997
Citation: VASSALO, D. V. et al. Effects of ouabain on vascular reactivity. Braz J Med Biol Res, Ribeirão Preto, v. 30, n. 4, p. 545-552, abr. 1997. Disponível em: <http://www.scielo.br/pdf/bjmbr/v30n4/2793C.pdf>. Acesso em: 7 fev. 2011.
Abstract: Ouabain is an endogenous substance occurring in the plasma in the nanomolar range, that has been proposed to increase vascular resistance and induce hypertension. This substance acts on the a-subunit of Na+,K+-ATPase inhibiting the Na+-pump activity. In the vascular smooth muscle this effect leads to intracellular Na+ accumulation that reduces the activity of the Na+/Ca2+ exchanger and to an increased vascular tone. It was also suggested that circulating ouabain, even in the nanomolar range, sensitizes the vascular smooth muscle to vasopressor substances. We tested the latter hypothesis by studying the effects of ouabain in the micromolar and nanomolar range on phenylephrine (PE)-evoked pressor responses. The experiments were performed in normotensive and hypertensive rats in vivo, under anesthesia, and in perfused rat tail vascular beds. The results showed that ouabain pretreatment increased the vasopressor responses to PE in vitro and in vivo. This sensitization after ouabain treatment was also observed in hypertensive animals which presented an enhanced vasopressor response to PE in comparison to normotensive animals. It is suggested that ouabain at nanomolar concentrations can sensitize vascular smooth muscle to vasopressor stimuli possibly contributing to increased tone in hypertension.
URI: http://repositorio.ufes.br/handle/10/606
ISSN: 1678-4510
Appears in Collections:DCFSI - Artigos publicados em periódicos

Files in This Item:
File Description SizeFormat 
2793C.pdf276.24 kBAdobe PDFView/Open


This item is licensed under a Creative Commons License Creative Commons