Helicobacter pylori lipopolysaccharide-provoked injury to rat gastroduodenal microvasculature involves inducible nitric oxide synthase.
The actions of a purified Helicobacter pylori lipopolysaccharide (3 mg x kg(-1), i.v.) on rat gastric antral and duodenal microvascular integrity (determined as radiolabelled albumin leakage) and the expression of the inducible nitric oxide (NO) synthase (iNOS; assessed by the citrulline assay) were investigated 4 h after challenge. Significant increases of albumin leakage and expression of iNOS in both antral and duodenal tissues were observed following challenge. Concurrent administration of the selective iNOS inhibitor, 1400W (N-(8-(aminomethyl)benzyl)-acetamidine; 0.2-1 mg x kg(-1), s.c.), with lipopolysaccharide, caused a dose-dependent attenuation of the gastric and duodenal albumin leakage. Thus, H. pylori lipopolysaccharide can initiate the expression of iNOS in the stomach and duodenum following systemic challenge, which can provoke gastroduodenal microvascular dysfunction.
Kiss
J
J
First Department of Medicine, University Medical School of Szeged, Hungary.
Lamarque
D
D
Moran
A P
AP
Pozsár
J
J
Morschl
E
E
László
F
F
Whittle
B J
BJ
D000578:Amidines / Q000494:pharmacology; D000818:Animals; D001596:Benzylamines / Q000494:pharmacology; D002199:Capillary Permeability / Q000187:drug effects*; D004064:Digestive System / Q000098:blood supply / Q000187:drug effects* / Q000473:pathology; D004305:Dose-Response Relationship, Drug; D004386:Duodenum / Q000187:drug effects / Q000201:enzymology / Q000473:pathology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D016480:Helicobacter pylori / Q000737:chemistry; D006801:Humans; D008070:Lipopolysaccharides / Q000633:toxicity*; D008297:Male; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D052247:Nitric Oxide Synthase Type II; D011706:Pyloric Antrum / Q000187:drug effects / Q000201:enzymology / Q000473:pathology; D051381:Rats; D017208:Rats, Wistar; D012709:Serum Albumin / Q000378:metabolism
D000578:Amidines; D001596:Benzylamines; D004791:Enzyme Inhibitors; D008070:Lipopolysaccharides; C104820:N-(3-(aminomethyl)benzyl)acetamidine; D012709:Serum Albumin; C496319:NOS2 protein, human; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; C496318:Nos2 protein, rat