Attenuation of Helicobacter pylori endotoxin-provoked rat intestinal inflammation by selective inhibition of the inducible nitric oxide synthase

We studied the actions of purified Helicobacter pylori endotoxin (3 mg kg(- 1), i.v.) on rat intestinal vascular permeability (assessed by the radiolab elled human serum albumin leakage technique) and on nitric oxide synthase i nduction (assessed by the citrulline assay) 4 h later. We found increased a lbumin leakage and expression of the inducible nitric oxide synthase in jej unum and colon, effects reversed by a selective inducible nitric oxide synt hase inhibitor N-(8-(aminomethyl)benzyl)-acetamidine (1400W; 0.2-1 mg kg(-1 ), s.c., concurrently with endotoxin). Thus, H. pylori endotoxin seems to b e capable of provoking an inflammatory response in the rat intestinal tissu e. Systemic liberation of H. pylori endotoxin might possibly attenuate jeju nal and colonic mucosal barrier function, a process mediated by the express ion of the inducible nitric oxide synthase. (C) 2001 Elsevier Science Ltd. All rights reserved.