A new severe acute necrotizing pancreatitis model induced by L-ornithine in rats.

OBJECTIVE: Intraperitoneal administration of large doses of L-arginine is known to induce severe acute pancreatitis in rats. We therefore set out to determine whether metabolites of L-arginine (L-ornithine, L-citrulline, and nitric oxide) cause pancreatitis. DESIGN: The authors conducted an in vivo animal study. SETTING: This study was conducted at a university research laboratory. SUBJECTS: Study subjects were male Wistar rats. INTERVENTIONS: Dose-response and time course changes of laboratory and histologic parameters of pancreatitis were determined after L-arginine, L-ornithine, L-citrulline, or sodium nitroprusside (nitric oxide donor) injection. MEASUREMENTS AND MAIN RESULTS: Intraperitoneal injection of 3 g/kg L-ornithine but not L-citrulline or nitroprusside caused severe acute pancreatitis; 4 to 6 g/kg L-ornithine killed the animals within hours. Serum and ascitic amylase activities were significantly increased, whereas pancreatic amylase activity was decreased after intraperitoneal injection of 3 g/kg L-ornithine. The increase in pancreatic trypsin activity (9-48 hrs) correlated with the degradation of IkappaB proteins and elevated interleukin-1beta levels. Oxidative stress in the pancreas was evident from 6 hrs; HSP72 synthesis was increased from 4 hrs after L-ornithine administration. Morphologic examination of the pancreas showed massive interstitial edema, apoptosis, and necrosis of acinar cells and infiltration of neutrophil granulocytes and monocytes 18 to 36 hrs after 3 g/kg L-ornithine injection. One month after L-ornithine injection, the pancreas appeared almost normal; the destructed parenchyma was partly replaced by fat. Equimolar administration of L-arginine resulted in lower pancreatic weight/body weight ratio, pancreatic myeloperoxidase activity, and histologic damage compared with the L-ornithine-treated group. L-ornithine levels in the blood were increased 54-fold after intraperitoneal administration of L-arginine. CONCLUSIONS: We have developed a simple, noninvasive model of acute necrotizing pancreatitis in rats by intraperitoneal injection of 3 g/kg L-ornithine. Interestingly, we found that, compared with L-arginine, L-ornithine was even more effective at inducing pancreatitis. Large doses of L-arginine produce a toxic effect on the pancreas, at least in part, through L-ornithine.

Zerumbone exerts a beneficial effect on inflammatory parameters of cholecystokinin octapeptide-induced experimental pancreatitis but fails to improve histology.

OBJECTIVE: Our experiments were designed to investigate the effects of zerumbone pretreatment on cholecystokinin octapeptide (CCK-8)-induced acute pancreatitis in rats. METHODS: Male Wistar rats weighing 240 to 280 g were divided into a control group, a group treated with CCK-8, a group receiving 20 mg/kg zerumbone before CCK-8 administration, and a group treated with zerumbone only. RESULTS: The serum amylase and lipase activities and the pancreatic weight-body weight ratio were significantly reduced by zerumbone pretreatment, but the drug failed to influence the histological parameters of pancreatitis. The anti-inflammatory effects of the drug were manifested in decreases in the cytosolic interleukin 6 and tumor necrosis factor alpha concentrations and an elevation in the I-kappaB concentration, whereas the antioxidant ability of zerumbone was demonstrated by reductions in inducible nitric oxide synthase, Mn- and Cu/Zn-superoxide dismutase activities in the zerumbone-treated rats. CONCLUSION: Zerumbone ameliorated the changes of several parameters of acute pancreatitis probably by interfering with I-kappaB degradation, but in the applied dose, it failed to influence the histology of the disease.

L-arginine-induced experimental pancreatitis.

Despite medical treatment, the lethality of severe acute pancreatitis is still high (20-30%). Therefore, it is very important to find good animal models to characterise the events of this severe disease. In 1984, Mizunuma et al. developed a new type of experimental necrotizing pancreatitis by intraperitoneal administration of a high dose of L-arginine in rats. This non-invasive model is highly reproducible and produces selective, dose-dependent acinar cell necrosis. Not only is this a good model to study the pathomechanisms of acute necrotizing pancreatitis, but it is also excellent to observe and influence the time course changes of the disease. By writing this review we illuminate some new aspects of cell physiology and pathology of acute necrotizing pancreatitis. Unfortunately, the reviews about acute experimental pancreatitis usually did not discuss this model. Therefore, the aim of this manuscript was to summarise the observations and address some challenges for the future in L-arginine-induced pancreatitis.

[Ulcerative colitis and eosinophilic corpus gastritis]. / Colitis ulcerosa és eosinophil corpusgastritis.

Ulcerative colitis seldom associated with nutritive and/or salicylate allergy. Authors present a case of both allergic events at the course of the disease. In 1996 a 19-year-old girl was referred with a history of blood in stool as well as diarrhoea, suggesting ulcerative proctitis. Biopsy revealed ulcerative colitis of the rectum mucosa with eosinophilic infiltration and 20% peripheral eosinophilia was found. Allergic origin and worm infection were ruled out, and after tinidazol treatment, four year elapsed without any signs or symptoms. In December 2000 blood in stools and upper abdominal complaints developed without peripheral eosinophilia. Gastroscopy and biopsy showed a mild chronic gastritis. Olsalazine, budesonide enema and famotidin treatment were started, but then later changed to mesalazine and pantoprazol, because of the constant stomach complaints. The next five months passed without any symptoms. The patient had to break off her seashore journey in July 2000 because of stomach complaints, vomiting and exsiccosis. Peripheral eosinophilia (27.3%) was evident. Gastroscopy revealed erosive ulcers and the biopsy showed eosinophilic gastritis. Biopsies from the jejunum, duodenum and antrum as well as enteroscopy and biopsies from the rectum showed mild eosinophilic infiltration. An allergy test proved the presence of IgE against salicylate, egg protein, seafood protein and the lymphocyte transformation test was also positive against salicylate. Oral food challenges proved to be negative and the amino-salicylate treatment was stopped. After a temporary symptom free period, bloody stools reappeared in May 2003; the peripheral eosinophilia still existed, but had decreased (22.2%). Esomeprazol, and methyl-prednisolone containing enema (40 mg/day/2 weeks) followed by budesonide enema twice a week resulted in a symptom free period and peripheral eosinophilia became almost normalised (6.2%). The authors report a case having ulcerative proctitis first, than nutritive and salicylate allergy with eosinophilic gastritis and a proctitis flare-up thereafter.