A novel model of ischemic enteritis induced in rats by stenosis of the superior mesenteric artery.
OBJECTIVE
We established a new model of ischemic enteritis in rats and evaluated its usefulness for screening prophylactic drugs.


METHODS
Male SD rats were used after 18 h of fasting. Under ether anesthesia, the superior mesenteric artery (SMA) was exposed, and a calibrated stenosis was produced by placing a needle on a blood vessel, ligating both the vessel and needle, and then removing the needle from the ligature.


RESULTS
The stenosis caused severe damage on the anti-mesenteric side of the small intestine within 3 days; the severity of the damage increased with the gauge of a needle. No damage occurred in the small intestine following the stenosis with a needle of less than 21 gauge. Multiple hemorrhagic lesions occurred at an incidence of 100% when a 23-gauge needle was used. The development of enteritis was accompanied by enterobacterial invasion in the mucosa, with an up- regulation of inducible nitric oxide synthase (iNOS) expression and nitric oxide (NO) production. The ischemia-induced enteritis was significantly prevented by repeated treatment with aminoguanidine (a selective iNOS inhibitor), L-NAME (a nonselective NOS inhibitor), ampicillin, and aztreonam (a gram- negative bacterium antibiotic), but not vancomycin (a gram-positive bacterium antibiotic).


CONCLUSIONS
These results showed that a novel model of ischemic enteritis is induced in rats by stenosis of the SMA, this model may be useful for screening drugs against ischemic enteritis, and gram-negative bacteria as well as iNOS/NO are involved in the pathogenesis of enteritis in this model.
Tohru
T
Kotani
Yoshino
Y
Komatsu
Yuka
Y
Nakamori
Koji
K
Takeuchi
D000818:Animals; D003251:Constriction, Pathologic; D004195:Disease Models, Animal; D004751:Enteritis / Q000188:drug therapy / Q000201:enzymology / Q000473:pathology; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D007413:Intestinal Mucosa / Q000098:blood supply / Q000201:enzymology / Q000473:pathology; D007511:Ischemia / Q000188:drug therapy / Q000201:enzymology / Q000473:pathology; D008297:Male; D008638:Mesenteric Arteries; D052247:Nitric Oxide Synthase Type II / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D051381:Rats; D015854:Up-Regulation / Q000187:drug effects
D004791:Enzyme Inhibitors; D052247:Nitric Oxide Synthase Type II; C496318:Nos2 protein, rat