Reactivity of the isolated perfused rat tail vascular bed
Braz. j. med. biol. res
;
30(7): 891-5, July 1997. graf
Artigo
em Inglês
| LILACS
| ID: lil-197242
RESUMO
Isolated segments of the perfused rat tail artery display a high basal tone when compared to other isolated arteries such as the mesenteric and are suitable for the assay of vasopressor agents. However, the perfusion of this artery in the entire tail has not yet been used for functional studies. The main purpose of the present study was to identify some aspects of the vascular reactivity of the rat tail vascular bed and validate this method to measure vascular reactivity. The tail severed from the body was perfused with Krebs solution containing different Ca2+ concentrations at different flow rates. Rats were anesthetized with sodium pentobarbital (65 mg/kg) and heparinized (500 U). The tail artery was dissected near the tail insertion, cannulated and perfused with Krebs solution plus 30 muM EDTA at 36 degrees Celsius and 2.5 ml/min and the procedures were started after equilibration of the perfusion pressure. In the first group a dose-response curve to phenylephrine (PE) (0.5, 1,2 and 5 mug, bolus injection) was obtained at different flow rates (1.5, 2.5 and 3.5 ml/min). The mean perfusion pressure increased with flow as well as PE vasopressor responses. In a second group the flow was changed (1.5,2,2.5,3 and 3.5 ml/min) at different Ca2+ concentrations (0.62, 1.25, 2.5 and 3.75 mM) in the Krebs solution. Increasing Ca2+ concentrations did not alter the flow-pressure relationship. In the third group a similar protocol was performed but the rat tail vascular bed was perfused with Krebs solution containing PE (0.1 mug/ml). There was an enhancement of the effects of PE with increasing external Ca2+ and flow. PE vasopressor responses increased after endothelial damage with air and CHAPS, suggesting an endothelial modulation of the tone of the rat tail vascular bed. These experiments validate the perfusion of the rat tail vascular bed as a method to investigate vascular reactivity.
Texto completo:
DisponíveL
Índice:
LILACS (Américas)
Assunto principal:
Perfusão
/
Fenilefrina
/
Artérias
/
Técnicas In Vitro
/
Modelos Biológicos
Limite:
Animais
Idioma:
Inglês
Revista:
Braz. j. med. biol. res
Assunto da revista:
Biologia
/
Medicina
Ano de publicação:
1997
Tipo de documento:
Artigo
Similares
MEDLINE
...
LILACS
LIS