Chronic ingestion of a potential food contaminant induces gastrointestinal inflammation in rats: role of nitric oxide and mast cells

Dig Dis Sci. 2000 Sep;45(9):1842-9. doi: 10.1023/a:1005509623060.


Chronic ingestion of xenobiotics could be pathogenic in the gastrointestinal tract. Recently, we showed that acute low administration of a food contaminant (diquat) induced intestinal secretion involving mast cells and nitric oxide. This work aimed to determine in rats: (1) the influence of a low level (0.1 mg/kg/day per os) chronic ingestion of diquat on gastrointestinal immune cells, and (2) the participation of nitric oxide synthases (NOS) in these effects. Diquat increased both gastric and jejunal myeloperoxidase activities, tissue histamine in vitro release after stimulation by 48/80, and mast cell numbers. Diquat did not alter gastric NOS but increased intestinal inducible NOS (iNOS) activity. L-NAME prevented diquat-induced gastric and intestinal mastocytosis and gastric but not intestinal inflammation. L-NAME reduced gastric constitutive NOS (cNOS) activity and reestablished control iNOS activity. Chronic low level ingestion of diquat induces a low-grade gastric and intestinal inflammation with mastocytosis and enhancement of intestinal iNOS activity.

MeSH terms

  • Animals
  • Diquat / administration & dosage
  • Diquat / toxicity*
  • Enzyme Inhibitors / pharmacology
  • Food Contamination
  • Gastric Mucosa / metabolism
  • Gastroenteritis / chemically induced*
  • Gastroenteritis / metabolism
  • Gastroenteritis / pathology
  • Herbicides / administration & dosage
  • Herbicides / toxicity*
  • Histamine Release
  • Jejunum / metabolism
  • Jejunum / pathology
  • Male
  • Mast Cells / pathology*
  • NG-Nitroarginine Methyl Ester / pharmacology
  • Nitric Oxide / metabolism*
  • Nitric Oxide Synthase / antagonists & inhibitors
  • Nitric Oxide Synthase / metabolism
  • Peroxidase / metabolism
  • Rats
  • Rats, Wistar
  • Stomach / pathology


  • Enzyme Inhibitors
  • Herbicides
  • Nitric Oxide
  • Diquat
  • Peroxidase
  • Nitric Oxide Synthase
  • NG-Nitroarginine Methyl Ester