Myogenic NOS and endogenous NO production are defective in colon from dystrophic (mdx) mice.
Am J Physiol Gastrointest Liver Physiol
; 281(5): G1264-70, 2001 Nov.
Article
en En
| MEDLINE
| ID: mdl-11668035
ABSTRACT
The aim of the present study was to evaluate whether alterations in the distribution and/or function of nitric oxide synthase (NOS) could be involved in the development of the spontaneous mechanical tone observed in colon from dystrophic (mdx) mice. By recording the intraluminal pressure of isolated colon from normal mice, we showed that N(omega)-nitro- L-arginine methyl ester (L-NAME) increased the tone, even in the presence of tetrodotoxin. The effect was prevented by L-arginine, nifedipine, or Ca(2+)-free solution. In colon from mdx mice, L-NAME was ineffective. Immunohistochemistry revealed that the presence and distribution of neuronal (nNOS), endothelial, and inducible NOS isoforms in smooth muscle cells and neurons of colon from mdx mice were the same as in controls. However, the expression of myogenic nNOS was markedly reduced in mdx mice. We conclude that there is a myogenic NOS in mouse colon that can tonically produce nitric oxide to limit influx of Ca(2+) through L-type voltage-dependent channels and modulate the mechanical tone. This mechanism appears to be defective in mdx mice.
Buscar en Google
Base de datos:
MEDLINE
Asunto principal:
Colon
/
Óxido Nítrico Sintasa
/
Distrofia Muscular de Duchenne
/
Músculo Liso
/
Óxido Nítrico
Idioma:
En
Revista:
Am J Physiol Gastrointest Liver Physiol
Asunto de la revista:
FISIOLOGIA
/
GASTROENTEROLOGIA
Año:
2001
Tipo del documento:
Article