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
Artículo
en Inglés
| LILACS
| ID: lil-595722
Biblioteca responsable:
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.
Texto completo:
Disponible
Colección:
Bases de datos internacionales
Contexto en salud:
Agenda de Salud Sostenible para las Américas
Problema de salud:
Objetivo 9: Enfermedades no transmisibles y salud mental
Base de datos:
LILACS
Asunto principal:
Polietilenglicoles
/
Cola (estructura animal)
/
Resistencia Vascular
/
Hipertensión
Tipo de estudio:
Estudio de evaluación
/
Estudio pronóstico
Límite:
Animales
Idioma:
Inglés
Revista:
Braz. j. med. biol. res
Asunto de la revista:
Biologia
/
Medicina
Año:
2011
Tipo del documento:
Artículo
País de afiliación:
Brasil
Institución/País de afiliación:
Universidade Federal Rural do Semi-Árido/BR
/
Universidade Federal do Espírito Santo/BR
/
Universidade de São Paulo/BR