Colitis and interleukin 1beta up-regulate inducible nitric oxide synthase and superoxide dismutase in rat myenteric neurons.
BACKGROUND & AIMS: Manganese superoxide dismutase (MnSOD) is rapidly induced in myenteric plexus neurons (MPNs) in acute colitis and may protect cells from nitric oxide toxicity. Inducible nitric oxide synthase (iNOS) regulation was examined in acute colitis, and MnSOD and iNOS were examined in primary cultures of MPNs. METHODS: Acute colitis in rats was induced with 5% acetic acid. iNOS messenger RNA (mRNA) was analyzed by Northern analysis, and reduced nicotinamide adenine dinucleotide phosphate diaphorase was used to identify potential NO synthase activity. MnSOD and iNOS mRNA levels were evaluated in cultured MPNs after treatment with tumor necrosis factor alpha, interleukin (IL) 1beta, or IL-6. iNOS and MnSOD protein expression in control and IL-1beta-treated neurons was evaluated by immunofluorescence microscopy. RESULTS: iNOS mRNA was detected in the mucosal and muscularis layers after the initiation of colitis. Reduced nicotinamide adenine dinucleotide phosphate diaphorase localized NO synthase activity to MPNs in controls and in epithelial cells and MPNs in the inflamed colon. In MPN cultures, tumor necrosis factor alpha and IL-1beta treatment resulted in induction of MnSOD, but only IL-1beta induced iNOS. Immunolocalization confirmed that the neurons were the primary source of iNOS and MnSOD. CONCLUSIONS: Induction of MnSOD and iNOS are coordinated and may limit NO cytotoxicity. The function of iNOS in gut neurons remains to be delineated.[1]References
- Colitis and interleukin 1beta up-regulate inducible nitric oxide synthase and superoxide dismutase in rat myenteric neurons. Valentine, J.F., Tannahill, C.L., Stevenot, S.A., Sallustio, J.E., Nick, H.S., Eaker, E.Y. Gastroenterology (1996) [Pubmed]
Annotations and hyperlinks in this abstract are from individual authors of WikiGenes or automatically generated by the WikiGenes Data Mining Engine. The abstract is from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.About WikiGenesOpen Access LicencePrivacy PolicyTerms of Useapsburg