Inhibition of nitric oxide synthase delays healing of chronic gastric ulcers.
We investigated the influence of inhibition of nitric oxide (NO) synthase, using NG-nitro-L-arginine (L-NNA) or NG-mono-methyl-L-arginine (L-NMMA), and the effects of exogenous donor of NO, such as glyceryl trinitrate (GTN), on the healing of chronic gastric ulcers induced by acetic acid, on gastric blood flow around the ulcer and on the number of capillaries in the granulation tissue at the ulcer bed. The inhibition of NO synthase resulted in a delay in ulcer healing and in a reduction in blood flow at the ulcer margin and in the number of capillaries in the granulation tissue at the ulcer bed. These effects of inhibition of NO synthase were antagonized, in part, by the administration of GTN or L-arginine but not D-arginine. We conclude that endogenous NO plays an important role in the maintenance of blood flow around the ulcer, in the angiogenesis in the granulation tissue and, thus, in the healing of gastric ulcers.
Konturek
S J
SJ
Institute of Physiology, University School of Medicine, Krakow, Poland.
Brzozowski
T
T
Majka
J
J
Pytko-Polonczyk
J
J
Stachura
J
J
D000085:Acetates; D019342:Acetic Acid; D000594:Amino Acid Oxidoreductases / Q000037:antagonists & inhibitors*; D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives* / Q000494:pharmacology; D005753:Gastric Mucosa / Q000098:blood supply; D008297:Male; D009569:Nitric Oxide / Q000037:antagonists & inhibitors / Q000502:physiology*; D019001:Nitric Oxide Synthase; D019335:Nitroarginine; D005996:Nitroglycerin / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D012039:Regional Blood Flow / Q000187:drug effects; D013270:Stomach / Q000098:blood supply; D013276:Stomach Ulcer / Q000139:chemically induced / Q000473:pathology / Q000503:physiopathology*; D019323:omega-N-Methylarginine
D000085:Acetates; D019335:Nitroarginine; D019323:omega-N-Methylarginine; D009569:Nitric Oxide; D001120:Arginine; D019001:Nitric Oxide Synthase; D000594:Amino Acid Oxidoreductases; D005996:Nitroglycerin; D019342:Acetic Acid