Role of neuronal and inducible nitric oxide synthases in the guinea pig ileum myenteric plexus during in vitro ischemia and reperfusion. Issue 2 (2nd January 2013)

• Record Type: Journal Article
• Authors: Giaroni, C.; Marchet, S.; Carpanese, E.; Prandoni, V.; Oldrini, R.; Bartolini, B.; Moro, E.; Vigetti, D.; Crema, F.; Lecchini, S.; Frigo, G.
• Is Part Of: Neurogastroenterology & motility. Volume 25:Issue 2(2013:Feb.)
• Page Start: e114
• Page End: e126
• Publication Date: 2013-01-02
• Subjects: Gastrointestinal system -- Motility -- Periodicals; Gastrointestinal system -- Innervation -- Periodicals; 616.33
• DOI: 10.1111/nmo.12061
• Languages: English
• ISSNs: 1350-1925

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p> <bold>Background </bold> Intestinal ischemia and reperfusion (I/R) injury leads to abnormalities in motility, namely delay of transit, caused by damage to myenteric neurons. Alterations of the nitrergic transmission may occur in these conditions. This study investigated whether an <italic>in vitro</italic> I/R injury may affect nitric oxide (NO) production from the myenteric plexus of the guinea pig ileum and which NO synthase (NOS) isoform is involved.</p> <p> <bold>Methods </bold> The distribution of the neuronal (n) and inducible (i) NOS was determined by immunohistochemistry during 60 min of glucose/oxygen deprivation (<italic>in vitro</italic> ischemia) followed by 60 min of reperfusion. The protein and mRNA levels of nNOS and iNOS were investigated by Western‐immunoblotting and real time RT‐PCR, respectively. NO levels were quantified as nitrite/nitrate.</p> <p> <bold>Key Results </bold> After <italic>in vitro</italic> I/R the proportion of nNOS‐expressing neurons and protein levels remained unchanged. nNOS mRNA levels increased 60 min after inducing ischemia and in the following 5 min of reperfusion. iNOS‐immunoreactive neurons, protein and mRNA levels were up‐regulated during the whole I/R period. A significant increase of nitrite/nitrate levels was observed in the first 5 min after inducing I/R and was significantly reduced by <italic>N</italic><sup>ω</sup>‐propyl‐<sc>l</sc>‐arginine and 1400 W, selective inhibitors of nNOS and iNOS, respectively.</p> <p> <bold>Conclusions & Inferences </bold> Our data demonstrate that both iNOS and nNOS represent sources for NO overproduction in ileal myenteric plexus during I/R, although iNOS undergoes more consistent changes suggesting a more relevant role for this isoform in the alterations occurring in myenteric neurons following I/R.</p> </abstract>