Endothelial nitric oxide synthase modulates gastric ulcer healing in rats.
Ma, Li, and John L. Wallace.
Mucosal Inflammation Research Group, Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada T2N 4N1
APStracts 7:0157G, 2000.
Nitric oxide has been shown to be beneficial for gastric ulcer healing. We determined the relative effects of endothelial and inducible nitric oxide synthases on gastric ulcer healing in rats. Ulcers were induced by serosal application of acetic acid. Ulcer severity, angiogenesis, and nitric oxide synthase expression were assessed 3-10 days later. The effects of inhibitors of nitric oxide synthase were also examined. Inducible nitric oxide synthase mRNA was only detected in ulcerated tissue (maximal at day 3), whereas the endothelial isoform mRNA was detected in normal tissue and increased during ulcer healing. Inducible nitric oxide synthase was expressed in inflammatory cells in the ulcer bed, whereas endothelial nitric oxide synthase was found in the vascular endothelium and in some mucosal cells in both normal and ulcerated tissues. Angiogenesis changed in parallel with endothelial nitric oxide synthase expression. N6-(iminoethyl)-l-lysine did not affect angiogenesis or ulcer healing, while "lgname" significantly reduced both. In conclusion, endothelial nitric oxide synthase, but not the inducible isoform, plays a significant role in gastric ulcer healing.
Received 18 January 2000; accepted in final form 7 March 2000
APS Manuscript Number G0026-0.
Article publication pending Am J Physiol Gastrointest Liver Physiol
ISSN 1080-4757 Copyright 2000 The American Physiological Society.
Published in APStracts on 29 August 2000