Drag reduction by polyethylene glycol in the tail arterial bed of normotensive and hypertensive rats
Braz. j. med. biol. res
; 44(8): 767-777, Aug. 2011. ilus
Article
em En
| LILACS
| ID: lil-595722
Biblioteca responsável:
BR1.1
ABSTRACT
This study was designed to evaluate the effect of drag reducer polymers (DRP) on arteries from normotensive (Wistar) and spontaneously hypertensive rats (SHR). Polyethylene glycol (PEG 4000 at 5000 ppm) was perfused in the tail arterial bed with (E+) and without endothelium (E-) from male, adult Wistar (N = 14) and SHR (N = 13) animals under basal conditions (constant flow at 2.5 mL/min). In these preparations, flow-pressure curves (1.5 to 10 mL/min) were constructed before and 1 h after PEG 4000 perfusion. Afterwards, the tail arterial bed was fixed and the internal diameters of the arteries were then measured by microscopy and drag reduction was assessed based on the values of wall shear stress (WSS) by computational simulation. In Wistar and SHR groups, perfusion of PEG 4000 significantly reduced pulsatile pressure (Wistar/E+ 17.5 ± 2.8; SHR/E+ 16.3 ± 2.7 percent), WSS (Wistar/E+ 36; SHR/E+ 40 percent) and the flow-pressure response. The E- reduced the effects of PEG 4000 on arteries from both groups, suggesting that endothelial damage decreased the effect of PEG 4000 as a DRP. Moreover, the effects of PEG 4000 were more pronounced in the tail arterial bed from SHR compared to Wistar rats. In conclusion, these data demonstrated for the first time that PEG 4000 was more effective in reducing the pressure-flow response as well as WSS in the tail arterial bed of hypertensive than of normotensive rats and these effects were amplified by, but not dependent on, endothelial integrity. Thus, these results show an additional mechanism of action of this polymer besides its mechanical effect through the release and/or bioavailability of endothelial factors.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
LILACS
Assunto principal:
Polietilenoglicóis
/
Cauda
/
Resistência Vascular
/
Hipertensão
Tipo de estudo:
Evaluation_studies
/
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Braz. j. med. biol. res
Assunto da revista:
BIOLOGIA
/
MEDICINA
Ano de publicação:
2011
Tipo de documento:
Article
País de afiliação:
Brasil