Oxidative stress, nitric oxide and prostaglandin E2 levels in the gastrointestinal tract of aging rats.
OBJECTIVE
To evaluate the presence of oxidative stress and alterations in the levels of two cytoprotective agents, prostaglandin E2 and nitric oxide, in the gastrointestinal tract of aging rats.


METHODS
The production of superoxide anion, lipid peroxides, levels of superoxide dismutase and catalase, and production of prostaglandin E2 and nitric oxide in the stomach and duodenum of rats were determined at 1.5, 3, 12, 18 and 24 months of age.


RESULTS
Oxidative stress was present in the stomach of the old rats (24 months), whereas prostaglandin E2 and nitric oxide production remained stable at 18 and 24 months. In the duodenum, no oxidative stress was observed at 24 months, but at 18 months, an increase in superoxide anion levels was detected. Prostaglandin E2 remained constant in the aged rats but nitric oxide decreased significantly at 24 months.


CONCLUSIONS
The absence of macroscopic gastric injury throughout the gastrointestinal tract indicates that the oxidative stress in the stomach and the significant decrease of nitric oxide in the duodenum in the old rats are not sufficient to disrupt the mucosal defence network. The results support the notion that the disruption of the mucosal network is essentially regulated by the cytoprotective agents prostaglandin E2 and nitric oxide, and that injury appears only when both substances are concurrently reduced.
Mármol
Frederic
F
Unitat de Farmacologia, Facultat de Medicina, IDIBAPS, Universitat de Barcelona, Barcelona, Spain.
Sánchez
Juan
J
López
Diego
D
Martínez
Nuria
N
Mitjavila
Maria Teresa
MT
Puig-Parellada
Pere
P
D000367:Age Factors; D000375:Aging / Q000378:metabolism*; D000704:Analysis of Variance; D000818:Animals; D016718:Arachidonic Acid / Q000378:metabolism; D002374:Catalase / Q000378:metabolism; D019610:Cytoprotection / Q000502:physiology; D015232:Dinoprostone / Q000032:analysis / Q000037:antagonists & inhibitors / Q000737:chemistry*; D004386:Duodenum / Q000737:chemistry / Q000378:metabolism; D005753:Gastric Mucosa / Q000737:chemistry / Q000378:metabolism / Q000473:pathology; D041981:Gastrointestinal Tract / Q000737:chemistry* / Q000502:physiology; D007413:Intestinal Mucosa / Q000737:chemistry / Q000378:metabolism / Q000473:pathology; D015227:Lipid Peroxidation; D008054:Lipid Peroxides / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism; D008297:Male; D009569:Nitric Oxide / Q000032:analysis / Q000737:chemistry* / Q000502:physiology; D018384:Oxidative Stress; D010100:Oxygen / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013482:Superoxide Dismutase / Q000037:antagonists & inhibitors / Q000378:metabolism; D013481:Superoxides / Q000037:antagonists & inhibitors / Q000378:metabolism; D017392:Thiobarbituric Acid Reactive Substances / Q000032:analysis / Q000378:metabolism; D013997:Time Factors
D008054:Lipid Peroxides; D017392:Thiobarbituric Acid Reactive Substances; D013481:Superoxides; D016718:Arachidonic Acid; D009569:Nitric Oxide; D002374:Catalase; D013482:Superoxide Dismutase; D015232:Dinoprostone; D010100:Oxygen