Selective cyclo-oxygenase-2 inhibitors aggravate ischaemia-reperfusion injury in the rat stomach.
1. Effects of indomethacin, the selective cyclo-oxygenase (COX)-2 inhibitors NS-398 and DFU, and dexamethasone on gastric damage induced by 30 min ischaemia followed by 60 min reperfusion (I-R) were investigated in rats. Modulation of gastric levels of COX-1 and COX-2 mRNA by I-R was evaluated using Northern blot and reverse transcription-polymerase chain reaction. 2. I-R-induced gastric damage was dose-dependently aggravated by administration of indomethacin (1 - 10 mg kg(-1)), NS-398 (0.4 - 4 mg kg(-1)) or DFU (0.02 - 2 mg kg(-1)) as assessed macroscopically and histologically. 3. Likewise, administration of dexamethasone (1 mg kg(-1)) significantly increased I-R damage. 4. Low doses of 16, 16-dimethyl-prostaglandin(PG)E(2), that did not protect against ethanol-induced mucosal damage, reversed the effects of the selective COX-2 inhibitors, indomethacin and dexamethasone. 5. I-R had no effect on gastric COX-1 mRNA levels but increased COX-2 mRNA levels in a time-dependent manner. Dexamethasone inhibited the I-R-induced expression of COX-2 mRNA. 6. I-R was not associated with a measurable increase in gastric mucosal formation of 6-keto-PGF(1alpha) and PGE(2). PG formation was substantially inhibited by indomethacin (10 mg kg(-1)) but was not significantly reduced by NS-398 (4 mg kg(-1)), DFU (2 mg kg(-1)) or dexamethasone (1 mg kg(-1)). 7. The findings indicate that selective COX-2 inhibitors and dexamethasone markedly enhance gastric damage induced by I-R. Thus, whereas COX-2 has no essential role in the maintenance of gastric mucosal integrity under basal conditions, COX-2 is rapidly induced in a pro-ulcerogenic setting and contributes to mucosal defence by minimizing injury. This suggests that in certain situations selective COX-2 inhibitors may have gastrotoxic effects.
Maricic
N
N
Department of Experimental Clinical Medicine, Ruhr-University of Bochum, D-44780 Bochum, Germany.
Ehrlich
K
K
Gretzer
B
B
Schuligoi
R
R
Respondek
M
M
Peskar
B M
BM
D000818:Animals; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors / Q000009:adverse effects*; D004305:Dose-Response Relationship, Drug; D005663:Furans / Q000009:adverse effects*; D005753:Gastric Mucosa / Q000187:drug effects; D007213:Indomethacin / Q000009:adverse effects*; D007527:Isoenzymes / Q000378:metabolism / Q000494:pharmacology*; D008297:Male; D008565:Membrane Proteins; D009578:Nitrobenzenes / Q000009:adverse effects*; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism / Q000494:pharmacology*; D011453:Prostaglandins / Q000627:therapeutic use; D012333:RNA, Messenger / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000139:chemically induced* / Q000188:drug therapy; D013449:Sulfonamides / Q000009:adverse effects*
C106876:5,5-dimethyl-3-(3-fluorophenyl)-4-(4-methylsulfonyl)phenyl-2(5H)-furanone; D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors; D005663:Furans; D007527:Isoenzymes; D008565:Membrane Proteins; D009578:Nitrobenzenes; D011453:Prostaglandins; D012333:RNA, Messenger; D013449:Sulfonamides; C080955:N-(2-cyclohexyloxy-4-nitrophenyl)methanesulfonamide; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D011451:Prostaglandin-Endoperoxide Synthases; C496513:Ptgs1 protein, rat; D007213:Indomethacin