OBJECTIVETo explore the changes in hemorheology and expression of neutrophil adhesion molecules CD18 and CD62L in pancreatic microcirculation of Caerulein induced experimental acute pancreatitis (AP).

METHODSThe Wistar rats (n = 21) were randomized into three groups. The model of AP was established by subcutaneous injection of Caerulein. The changes of apparent viscosity of whole blood were measured by Low- shear 30 rheometer. The expression of adhesion molecules on the surface of neutrophil in duced by shear stress was used with stationary control. CD18 expression was increased on neutrophils treated with shear rate, and andanalyzed using flow cytometry.

RESULTSRat treated with Caerulein showed hyperamyleimia (t = 69.029, t = 79.734, P < 0.05). Blood viscosity of two AP groups were significantly elevated (0.512 s(-1): t = 10.725, t = 16.945; 5.96 s(-1): t = 12.781, t = 11.992, P < 0.05). Compared with stationary control, CD18 expression was increased on neutrophil treated with shear rate, and significantly induced with shear rate >/= 94.5 s(-1) (94.5 s(-1): t = 7.403, t = 13.323, t = 16.655; 128.5 s(-1): t = 10.092, t = 28.531, t = 24.563, P < 0.05). The expression of CD62L was less sensitive to low shear rate, and began to be down-regulated significantly when the shear rate >/= 94.5 s(-1) (94.5 s(-1): t = 10.687, t = 19.376, t = 12.848; 128.5 s(-1): t = 26.152, t = 48.402, t = 56.814, P < 0.05).

CONCLUSIONSThe changes of apparent viscosity of whole blood, and the effect of fluid shear stress on the expression of neutrophil adhesion molecules CD18, CD62L may play an important role in the pancreatic microcirculatory failure of acute pancreatitis.

Acute Disease ; Animals ; Ceruletide ; Flow Cytometry ; Hemorheology ; Microcirculation ; Neutrophils ; Pancreatitis ; Rats, Wistar

OBJECTIVETo set up a convenient nontraumatic mouse model of severe acute pancreatitis(SAP).

METHODSMice received intraperitoneal injections with caerulein and lipopolysaccharide (LPS). Serum amylase and pancreatic moisture content were measured during experiment. The histo pathological changes of pancreas and relevant organs were observed under light microscope.

RESULTSSerum amylase and pancreatic moisture content increased and pancreatic interstitial edema, inflammatory cellular infiltration, parenchymal necrosis as well as parenchymal hemorrhages were happened in the caerulein plus LPS group, and the lesions of other organs including stomach, ileum, spleen, and lung were seen as well. In the careulein group, there was only pancreatic interstitial edema with no parenchmal necrosis or hemorrhage, and the rest organs were normal.

CONCLUSIONSThe SAP mouse model induced by caerulein plus LPS has the same pathological characteristics of human SAP, which can be used for human SAP studies.

Animals ; Ceruletide ; Disease Models, Animal ; Female ; Injections, Intraperitoneal ; Lipopolysaccharides ; Mice ; Pancreatitis, Acute Necrotizing ; chemically induced

Cerulein-induced pancreatitis is similar to human edematous pancreatitis, characterized by the dysregulation of digestive enzyme production, edema formation, and an infiltration of inflammatory cells into the pancreas. We previously showed that the Janus kinase 2 (JAK2)/STAT3 pathway mediates inflammatory signaling in cerulein-stimulated pancreatic acinar cells. PPAR-γ has been implicated in the regulation of inflammatory responses in several cells. In the present study, we investigated the role of PPAR-γ in cerulein-induced activation of JAK2/STAT3 in pancreatic acinar cells. Treatment with cerulein induced the activation of JAK2/STAT3 and PPAR-γ expression in AR42J cells. Cerulein-induced PPAR-γ expression was inhibited by AG490, a JAK2/STAT3 inhibitor, in AR42J cells. An immunoprecipitation analysis showed that PPAR-γ binds to STAT3 in cerulein-stimulated AR42J cells. Down-regulation of PPAR-γ by siRNA increased STAT3 phosphorylation in AR42J cells stimulated with cerulein. These results show that PPAR-γ inactivates STAT3 by directly interacting with STAT3 in cerulein-stimulated pancreatic acinar cells. Overexpression of PPAR-γ may be beneficial for preventing pancreatitis by suppressing the activation of STAT3 in pancreatic acinar cells.
Acinar Cells* ; Ceruletide ; Down-Regulation ; Edema ; Humans ; Immunoprecipitation ; Janus Kinase 2 ; Pancreas ; Pancreatitis ; Peroxisomes* ; Phosphorylation ; RNA, Small Interfering

Oral cholecystography is one of the most relible and widely used x-ray examination which enables us to observe not only morphological features of the gallbladder (GB) but also its functioning state. It was disclosed that functional evaluation of the GB is mandatory to recognize such kinetic disorders of the viscus as acalculous cholecystitis or dyskinesia. For the purpose of functional evaluation, fat meal has been used traditionally. Recently, cholecystokinin(CCK) and ceruletide were introduced into clinical diagnosis of the GB, the usefulness of which we have confirmed. In the present study we have made an attempt at improving cholecystagogic effect of conventional fat meals(FM) such as whole mild and egg yolk by changing the posture of the examined from sitting up to right decubitus position after the ingestion of fat meal. The hypothesis involved in this study is that the presence of quantitatively more fat meal in the duodenum per unit time may result in more effective cholecystagogic action and such a setting would be created by enhancement of pyloric passage of fat meal by decubitus posturing. Clinical materials consisted of 280 normal oral GB series (136 males and 144 females) andthey were divided into 4 equally numbered groups of mild sitting and mild decubitus and egg sitting and eggdecubitus. Upon confirming satisfactory opacification of the GB 11 hours after the ingestion of 3g of sodiumipodate or iopanoci acid either 2 pieces of medium sized hen's egg yolk were given. The xaminess were then allowed either sitting up comfortably on a bench or lying down on the right flank on a couch. After the ingestion of fat mean, x ray was taken at the end of 30 minutes in all but the mild decubitus group in which x rays were taken serially at the end of 5, 15, 30 and 60 minutes. The frontal area of each opacified GB was measured by using aplanimeter and the contraction rate before and after fat meal stimulation was calculated by the following equation and delineation of the biliary tree was analyzed in each group. Contraction rate (%) = (1
Acalculous Cholecystitis ; Biliary Tract ; Ceruletide ; Cholecystography ; Deception ; Diagnosis ; Duodenum ; Dyskinesias ; Eating ; Egg Yolk ; Gallbladder ; Humans ; Male ; Meals ; Ovum ; Posture

BACKGROUND: Many protease inhibitors show a protective effect for acute pancreatitis as seen in animal models. In previous studies, the protease inhibitors were administered before induction of pancreatitis, and there are few published reports examining effects when these agents were administered after induction of pancreatitis. The timing of drug administration may provide an explanation for the ineffectiveness of protease inhibitors for the treatment of patients with acute pancreatitis. Herein, we assessed the protective effect of nafamostat mesilate (NM), a potent protease inhibitor, in a mouse model of cerulean-induced pancreatitis and compared the results of administering the drug before and after the induction of pancreatitis. METHODS: Cerulein, a cholecystokinin analogue, was injected into mice intraperitoneally to induce pancreatitis. The mice received intravenous NM administration before and after the induction of pancreatitis. The serum concentration of amylase and lipase was measured, histological changes were measured, and the tissue expression of myeloperoxidase was measured to assess the degree of inflammation. Expression of p38 MAPK (mitogen-activated protein kinase), phospho-p38 MAPK, and IL-6 (interleukin-6) in tissue was evaluated. RESULTS: Acute pancreatitis was induced successfully by intraperitoneal injection of cerulein. Acute pancreatitis could be prevented when NM was administered before the induction of pancreatits. However, the effect was not guaranteed when given after the induction of pancreatitis. For a group of mice with induced pancreatitis, tissue expression of phospho-p38 MAPK was prominent and there was no marked difference in the expression of IL-6 between groups with or without induced pancreatitits. CONCLUSIONS: Although the efficacy of NM for treatment of acute pancreatitis is doubtful, pretreatment with NM for an expected condition like endoscopic retrograde cholangiopancreatography (ERCP), might be helpful for the prevention of pancreatitis.
Amylases ; Animals ; Ceruletide ; Cholangiopancreatography, Endoscopic Retrograde ; Cholecystokinin ; Humans ; Inflammation ; Injections, Intraperitoneal ; Interleukin-6 ; Lipase ; Mesylates* ; Mice ; Models, Animal ; p38 Mitogen-Activated Protein Kinases ; Pancreatitis* ; Peroxidase ; Protease Inhibitors

The role of PACAP (pituitary adenylate cyclase activating polypeptide), a peptidergic transmitter, in the pathogenesis of acute pancreatitis is not yet clear. This experiment was conducted to examine the action of exogenous PACAP on rat pancreas and on the course of experimental acute pancreatitis. The results showed that 5-30 microg/kg of PACAP slightly raised the serum amylase level, induced pancreatic edema (23.88% +/- 2.532%-25.86% +/- 1.974% of experiment groups versus 29.21% +/- 5.657% of control group), inflammatory cell infiltration, vacuolization of acinar cells, and occasionally fatty and parenchymal necroses. 15-30 microg/kg of PACAP aggravated cerulein-induced acute pancreatitis; the pancreatic edema became more marked (13.45% +/- 2.045%-17.66% +/- 4.652% of expreiment groups versus 21.83% +/- 3.013% of cerulein group, P<0.05), the serum amylase level became higher; and ascites, pancreatic bleeding, fatty and parenchymal necroses, and extensive vacuolization of acinar cells appeared. For sodium taurocholate-induced pancreatitis, 5-10 microg/kg of PACAP mildly attenuated the pancreatic edema, reduced the serum amylase level (1986.91 +/- 710.97-2944.33 +/- 1182.47 IU/L vs 3690.87 +/- 2277.99 IU/L, P<0.05), whereas it caused multifocal hemorrhage and prominent necrosis in pancreas. Except the cerulein-induced pancreatitis groups, other groups were found to have reduced pancreatic functional capillary density (FCD); when pancreatic edema was taken into consideration and calibrated FCD was introduced (FCD weighted against pancreatic wet/dry ratio), all groups revealed increases in pancreatic functional capillaries when compared with normal control. In conclusion, PACAP is proinflammatory in the pathogenesis of acute pancreatitis, PACAP plus cerulein can induce acute hemorrhagic/necrotizing pancreatitis, and the action of PACAP on cerulein-induced panceatitis may differ from that on sodium taurocholate-induced one. In this experiment, pancreatic FCD was underestimated due to pancreatic edema.
Amylases ; blood ; Animals ; Capillaries ; pathology ; Ceruletide ; Disease Models, Animal ; Male ; Pancreas ; blood supply ; Pancreatitis, Acute Necrotizing ; chemically induced ; enzymology ; pathology ; Rats ; Rats, Wistar

BACKGROUNDIn patients suffering from acute pancreatitis, the pathogenesis is not completely understood, and several recent studies in vitro suggested that heat shock proteins might play an important role in cell signaling. To investigate the possible role of extracellular heat shock protein 70 (Hsp70) in pancreatitis, toll-like receptor-4 (TLR4)-deficient and wild-type mice were administered with exogenous Hsp70 during the course of cerulein-induced pancreatitis (CIP).

METHODSAcute pancreatitis was induced by 5 intraperitoneal injections of cerulein at hourly intervals, and then treated with recombinant Hsp70 through the caudal vein 4 hours after the start of cerulein injections. Subsequently serum amylase and serum cytokines levels were detected. Histologic alteration of the pancreas was evaluated. Tumor necrosis factor alpha (TNF-alpha) concentrations and myeloperoxidase (MPO) activity in both pancreas and lungs were analyzed. The nuclear factor kappa B (NF-kappaB) activation in pancreatic tissue was measured using a sensitive RelA enzyme-linked immunosorbent assay.

RESULTSTreatment with recombinant Hsp70 to wild-type mice in CIP resulted in significant aggravation of inflammation in pancreas, elevated levels of serum cytokines, up-regulation of pulmonary MPO activity and increase of lung tissues TNF-alpha concentrations. In contrast, treatment with Hsp70 to TLR4-deficient mice had little effect on serum cytokines levels, pancreatic inflammation, pulmonary MPO activity and TNF-alpha concentrations.

CONCLUSIONSThe results suggest that extracellular Hsp70 might induce systemic inflammatory response syndrome (SIRS)-like response in vivo and TLR4 might be involved in the Hsp70-mediated activation of inflammatory reaction in the progression of CIP without infection.

Acute Disease ; Animals ; Ceruletide ; toxicity ; Female ; HSP70 Heat-Shock Proteins ; physiology ; Male ; Mice ; Mice, Inbred C57BL ; Pancreatitis ; etiology ; Systemic Inflammatory Response Syndrome ; etiology ; Toll-Like Receptor 4 ; physiology

To study the expression of X-linked inhibitor of apoptosis protein (XIAP) and cell apoptosis in vitro model of acute pancreatitis (AP), we carried out experiments to stimulate AR42J cell line with caerulein (10(-8) mol/L) for 12 hours, then collected cells at various time points (0 h, 4 h, 8 h, 12 h, and 24 h, respectively). We then observed the morphologic changes of AR42J cells with the stimulation of caerulein with electronic microscope. The gene expression of XIAP, caspase-3 and caspase-9 was detected using real-time fluorescence quantitative polymerase chain reaction (FQ-PCR), and the protein expression of XIAP was assessed by western blot. The activation of nuclear factor-kappa B (NF-kappaB) was measured by flow cytometry (FCM). With the stimulation of caerulein, the expression of XIAP and the NF-kappaB activation could first decrease and then increase, but the change of caspase-3 and caspase-9 expressions were opposite. XIAP may inhibit the cell apoptosis in rat pancreatic acinus AR42J cell lines at first with the stimulation of caerulein, then NF-kappaB can upgrade the expression of XIAP and increase the cell apoptosis.
Acinar Cells ; cytology ; metabolism ; Animals ; Apoptosis ; physiology ; Cell Line ; Ceruletide ; pharmacology ; NF-kappa B ; metabolism ; Pancreas ; cytology ; metabolism ; Pancreatitis ; metabolism ; Rats ; X-Linked Inhibitor of Apoptosis Protein ; genetics ; metabolism

It has been suggested that oxygen free radicals are involved in the initiation process of acute pancreatitis, although its pathogenesis is not clear. This study evaluates the roles of oxygen radicals and the effects of small molecular antioxidants (rebamipide, N-acetyl-cysteine, allopurinol, beta-carotene) on the development of cerulein-induced acute pancreatitis. Acute edematous pancreatitis was induced by the intravenous infusion of cerulein at supramaximal dose of 10 mug/kg/hour for 3.5 hours. The effects of antioxidants, rebamipide (100 mg/kg, i.p.), N-acetyl-cysteine (200 mg/kg, i.v.), allopurinol (20 mg/kg/hour), beta-carotene (50 mg/kg, i.p.), were examined. Cerulein administration resulted in a significant increase in serum amylase activity and pancreatic malondialdehyde (MDA), but not glutathione peroxidase (GSHpx). The glutathione (GSH) content in pancreatic tissue decreased dramatically. Pretreatment of N-acetyl-cysteine significantly decreased the cerulein-induced hyperamylasemia and maintained GSH content in pancreas, but MDA was slightly decreased. In addition, N-acetyl-cysteine ameliorated histological damage. Allopurinol and beta-carotene attenuated cerulein-induced hyperamylasemia, but histologically there was no difference from control. These results indicate that oxygen free radicals play an important role in the initiation of experimental acute pancreatitis. N-acetyl-cysteine is an effective antioxidant that ameliorates the cerulein-induced acute pancreatitis, and the possible therapeutic application of antioxidants against acute pancreatitis needs a further evaluation.
Allopurinol ; Amylases ; Animals ; Antioxidants* ; beta Carotene ; Ceruletide ; Free Radicals ; Glutathione ; Glutathione Peroxidase ; Hyperamylasemia ; Infusions, Intravenous ; Malondialdehyde ; Oxygen ; Pancreas ; Pancreatitis* ; Rats* ; Reactive Oxygen Species

BACKGROUND: Chronic pancreatitis (CP) is an irreversible progressive disease that destroys exocrine parenchyma, which are replaced by fibrous tissue. As pancreatic fibrosis is a key feature of CP, reducing fibrotic protein content in the pancreas is crucial for preventing CP. Studies suggest that NF-κB facilitates the expression of fibrotic mediators in pancreas and protein kinase C-δ (PKC-δ) regulates NF-κB activation in stimulated pancreatic acinar cells. Docosahexaenoic acid (DHA) is an omega-3 fatty acid having anti-inflammatory and anti-fibrotic effects. It has been shown to inhibit NF-κB activity in cerulein-stimulated pancreatic acinar cells which is a cellular model of CP. In the present study, we investigated if DHA inhibits expression of fibrotic mediators by reducing PKC-δ and NF-κB expression in mouse pancreatic tissues with CP.METHODS: For six weeks, mice were weekly induced for acute pancreatitis to develop CP. Furthermore, acute pancreatitis was induced by hourly intraperitoneal injections of cerulein (50 μg/kg × 7). Mice were administered DHA (10 μM) via drinking water before and after CP induction.RESULTS: Cerulein-induced pancreatic damages like decreased pancreatic weight/total body weight, leukocyte infiltration, necrosis of acinar cells, and vacuolization were found to be inhibited by DHA. Additionally, DHA inhibited cerulein-induced fibrotic mediators like alpha-smooth muscle actin and fibronectin in pancreas. DHA reduced expression of PKC-δ and NF-κB p65 in pancreatic tissues of cerulein-treated mice.CONCLUSIONS: DHA may be beneficial in preventing CP by suppressing pancreatic expression of fibrotic mediators.
Acinar Cells ; Actins ; Animals ; Body Weight ; Ceruletide ; Drinking Water ; Fibronectins ; Fibrosis ; Injections, Intraperitoneal ; Leukocytes ; Mice ; Necrosis ; Pancreas ; Pancreatitis ; Pancreatitis, Chronic ; Protein Kinases