TY - JOUR
T1 - Myogenic NOS and endogenous NO production are defective in colon from dystrophic (mdx) mice
AU - Mule', Flavia
AU - Serio, Rosa Maria
AU - Corsani, Letizia
AU - Mulè, Flavia
AU - Vannucchi, Maria Giuliana
AU - Faussone-Pellegrini, Maria Simonetta
PY - 2001
Y1 - 2001
N2 - 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 Nω-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 Ca2+-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 Ca2+ through L-type voltage-dependent channels and modulate the mechanical tone. This mechanism appears to be defective in mdx mice.
AB - 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 Nω-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 Ca2+-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 Ca2+ through L-type voltage-dependent channels and modulate the mechanical tone. This mechanism appears to be defective in mdx mice.
KW - Duchenne muscular dystrophy
KW - Gastroenterology
KW - Immunohistochemistry
KW - Intestinal smooth muscle
KW - Nitric oxide
KW - Nitric oxide synthase
KW - Physiology
KW - Physiology (medical)
KW - Spontaneous tone
KW - Duchenne muscular dystrophy
KW - Gastroenterology
KW - Immunohistochemistry
KW - Intestinal smooth muscle
KW - Nitric oxide
KW - Nitric oxide synthase
KW - Physiology
KW - Physiology (medical)
KW - Spontaneous tone
UR - http://hdl.handle.net/10447/199068
M3 - Article
VL - 281
SP - 1264
EP - 1270
JO - American Journal of Physiology - Gastrointestinal and Liver Physiology
JF - American Journal of Physiology - Gastrointestinal and Liver Physiology
SN - 0193-1857
ER -