0000000001012870
AUTHOR
M. G. Vannucchi
Altered tachykinergic influence on gastric mechanical activity in mdx mice
Abstract This study investigated whether alterationsin gastric activity in dystrophic mdx mouse can beattributed to dysfunctions of tachykinins. Endolumi-nal pressure was recorded and the expression ofneuronal nitric oxide synthase (nNOS), NK1 and NK2neurokinin receptors was investigated by immunoh-istochemistry. SR48968, NK2 receptor antagonist, butnot SR140333, NK1 receptor antagonist, decreased thetone only in mdx gastric preparations. In the presenceof N x -nitro- L -arginine methyl ester ( L -NAME), inhib-itor of NOS, SR48968 reduced the tone also in normalstomach. [Sar 9 , Met(O 2 ) 11 ]-SP, agonist of NK1 recep-tors, caused tetrodotoxin-sensitive relaxations, antag-onized by SR140333…
Myogenic NOS and endogenous NO production are defective in colon from dystrophic (mdx) mice
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 m…