Effects of lipopolysaccharide on gastric stasis: role of cyclooxygenase.
This study was done to examine the role of cyclooxygenase (COX) in lipopolysaccharide (LPS)-induced gastroprotection and gastric stasis. In conscious rats, LPS dose and time dependently increased gastric luminal fluid accumulation. LPS decreased blood flow (laser Doppler) and prevented gastric injury from acidified ethanol at time points before significant fluid accumulation occurred. LPS increased COX-2 but not COX-1 expression. In contrast, LPS decreased gastric mucosal prostaglandin synthesis. LPS-induced gastric luminal fluid accumulation was negated by both nonselective COX inhibition with salicylate and selective COX-2 inhibition with NS-398 but not by selective COX-1 inhibition with SC-560. Neither salicylate nor NS-398 blocked LPS-induced gastroprotection. LPS-induced gastroprotection does not depend entirely on accumulation of luminal fluid and is independent of COX-1 and COX-2. However, the ability of LPS to cause gastric stasis and increase gastric luminal fluid accumulation involves COX-2.
West
Sonlee D
SD
Department of Surgery, University of Texas Medical School, Houston, Texas, 77030, USA.
Suliburk
James W
JW
Smith
Gregory S
GS
Mercer
David W
DW
D000818:Animals; D001483:Base Sequence; D015415:Biomarkers / Q000032:analysis; D001707:Biopsy, Needle; D051545:Cyclooxygenase 1 / Q000187:drug effects / Q000378:metabolism*; D051546:Cyclooxygenase 2 / Q000187:drug effects / Q000378:metabolism*; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology*; D004195:Disease Models, Animal; D005260:Female; D005753:Gastric Mucosa / Q000187:drug effects / Q000473:pathology; D018589:Gastroparesis / Q000188:drug therapy* / Q000473:pathology* / Q000503:physiopathology; D007150:Immunohistochemistry; D008070:Lipopolysaccharides; D008969:Molecular Sequence Data; D011336:Probability; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D012016:Reference Values; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012680:Sensitivity and Specificity
D015415:Biomarkers; D016861:Cyclooxygenase Inhibitors; D008070:Lipopolysaccharides; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2