Substance P increases microvascular permeability via nitric oxide-mediated convective pathways.
Am J Physiol
; 268(4 Pt 2): R1060-8, 1995 Apr.
Article
em En
| MEDLINE
| ID: mdl-7537470
ABSTRACT
The goal of these studies was to examine the effects of substance P, a tachykinin neuropeptide, on pathways of microvascular permeability. Individual frog mesenteric venular capillaries were cannulated, and albumin apparent permeability coefficients (Ps) were determined by quantitative fluorescence microscopy. Ps of albumin (PsAlb) rose from 6.8 +/- 1.8 (SE) cm.s-1.10(7) at control to 22.3 +/- 2.3 cm.s-1.10(7) when substance P (10(-11) M) was perfused. The effect of increased microvessel permeability induced by substance P (10(-11) M) was blocked with the nonpeptide substance P receptor antagonist CP-96,345 and NG-nitro-L-arginine methyl ester (L-NAME), an inhibitor of nitric oxide synthase. PsAlb increased 0.99 cm.s-1.10(7) for every cmH2O increase in microvessel pressure after treatment of the vessel with substance P, demonstrating coupling of albumin flux to transvascular water flow. In conclusion, the mechanism of increased microvessel permeability in response to substance P appears to be the result of receptor-mediated increase in nitric oxide production and formation of water-filled convective pathways presumably located between adjacent endothelial cells.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Permeabilidade Capilar
/
Substância P
/
Óxido Nítrico
Limite:
Animals
Idioma:
En
Revista:
Am J Physiol
Ano de publicação:
1995
Tipo de documento:
Article
País de afiliação:
Estados Unidos