Bile and pancreatic juice exclusion activates acinar stress kinases and exacerbates gallstone pancreatitis

HYPOTHESIS: Bile and pancreatic juice exclusion from gut activates acinar stress kinases and exacerbates gallstone pancreatitis as evidenced by the ameliorating effects of replacement therapy in an experimental model of duct ligation-induced acute pancreatitis. In the early stages of gallstone pancreatitis, bile-pancreatic juice cannot enter the gut. Enteral exclusion worsens pancreatitis by causing feedback hyperstimulation of the exocrine pancreas that activates acinar cell stress kinases. Investigations using a unique surgical model, the Donor Rat Model, showed that duodenal replacement of bile-pancreatic juice in rats with duct ligation attenuates pancreatic stress kinase activation, reduces pancreatic cytokine production, and ameliorates pancreatic morphologic changes. These findings suggest that exclusion-induced acinar hyperstimulation, in the presence of duct obstruction, exacerbates acute pancreatitis via stress kinase activation. Although acinar hyperstimulation has often been implicated in the pathogenesis of acute pancreatitis, the lack of supporting evidence remains a conspicuous void. The proposed hypothesis draws on fresh evidence to present a new paradigm that reexamines the role of exocrine pancreatic hyperstimulation in gallstone pancreatitis pathogenesis.     

Bile-pancreatic juice exclusion increases cholinergic M3 and CCK-A receptor expression and interleukin-6 production in ligation-induced acute pancreatitis

BACKGROUND: Using an original model, the Donor Rat Model, we showed that bile-pancreatic juice (BPJ) exclusion from gut exacerbates ligation-induced acute pancreatitis in rats. We also showed that muscarinic cholinergic M3 and CCK-A receptor expression is induced following duct ligation. Increased receptor number potentially could exacerbate cytokine production. We hypothesize that BPJ exclusion is responsible for M3 and CCK-A receptor induction and increased interleukin-6 (IL-6) production. METHODS: M3 and CCK-A receptor expression and IL-6 production were compared in rat pancreata 1 to 3 hours after duct ligation with or without BPJ replacement. RESULTS: Our studies showed that BPJ replacement attenuates duct ligation-induced increases in M3 and CCK-A receptor expression and IL-6 production. CONCLUSIONS: In this model, BPJ exclusion from gut induces M3 and CCK-A receptor expression and increases IL-6 production. In this experimental corollary of gallstone pancreatitis, BPJ exclusion from gut may play a key role in the mechanism of disease pathogenesis.     

Exacerbation of acute pancreatitis by combined cholinergic stimulation and duct obstruction

BACKGROUND: The role of cholinergic pathways in the pathogenesis of bile-pancreatic duct ligation (BPDL)-induced acute pancreatitis in rats remains controversial. We hypothesized that cholinergic stimulation exacerbates acute pancreatic inflammation in the presence of duct obstruction. METHODS: We studied 34 rats divided into 5 groups as follows: (1) sham operation; (2) BPDL; (3) BPDL with duodenal bile-pancreatic juice (BPJ) replacement fresh from a donor rat; (4) BPDL with BPJ replacement as in 3 above, and carbachol (CCh) 5 ug/h subcutaneously; or (5) CCh 5 ug/h subcutaneously only. Rats were killed after 6 hours. RESULTS: The P value was less than .05 by analysis of variance. Pancreatic morphologic changes and zymogen fraction hyperamylasemia seen with duct ligation (2 vs. 1) were ameliorated significantly by duodenal BPJ replacement (3 vs. 2), but not when exogenous CCh was administered (4 vs. 3), whereas CCh alone showed no significant changes compared with sham (5 vs. 1). CONCLUSIONS: Cholinergic stimulation and duct obstruction synergistically amplify acinar hyperstimulation and exacerbate acute pancreatitis.     

The role of p65 NF-kB/RelA in pancreatitis-induced kupffer cell apoptosis

Acute pancreatitis induces liver injury by upregulating Kupffer cell-derived Fas/FasL; on the other hand, acute pancreatitis induces apoptosis of Kupffer cells via NF-kB-dependent pathways. The balance between upregulation of Fas/FasL and Fas/FasL-induced apoptosis of its originator cell may determine the severity of pancreatitis-related liver injury. The aim of our study was to determine the role of p65 NF-kB/RelA in pancreatitis-induced Kupffer cell apoptosis. Acute pancreatitis was induced in NIH Swiss mice by a choline-deficient ethionine-supplement (CDE) diet. In vitro mouse Kupffer cell line was transfected with p65 siRNA and treated with pancreatic elastase to mimic pancreatitis. CDE pancreatitis upregulated nuclear translocation of p65 NF-kB/RelA, Fas/FasL, caspase-3, and DNA fragmentation in mice livers (all P<0.001). In vitro, pancreatic elastase mimicked CDE-pancreatitis by upregulating nuclear translocation of p65 NF-kB/RelA, Fas/FasL, caspase-3, DNA fragmentation, and apoptosis in Kupffer cells (all P<0.001). Transfection with p65 siRNA attenuated the elastase-induced nuclear translocation of p65 NF-kB/RelA, upregulation of Fas/FasL, caspase-3, DNA fragmentation, and apoptosis in Kupffer cells (all P<0.001). Acute pancreatitis activates p65 NF-kB/RelA and induces apoptosis of Kupffer cells. Inhibition of p65NF-kB/RelA attenuates elastase-induced upregulation of proapoptotic pathways and apoptosis in Kupffer cells. The ability of Kupffer cells to autoregulate their stress response by inducing self-apoptosis warrants further investigation. Presented at the Forty-Sixth Annual Meeting of The Society for Surgery of the Alimentary Tract, Chicago, Illinois, May 14–19, 2005 (poster presentation). Supported by VA Merit Award (M.M.) and Dr. Bob Haines Pancreatitis Research Fund (M.M.).     

Murine pancreatic duct ligation induces stress kinase activation, acute pancreatitis, and acute lung injury

Background

Acute lung injury is a major determinant of outcomes in acute pancreatitis. We evaluated acute lung injury and stress kinase activation in ligation-induced acute pancreatitis in mice.

Methods

Mice with duct ligation or sham operation were killed after 24 or 48 hours.

Results

In addition to acute pancreatitis, duct ligation was associated with pulmonary morphologic changes indicative of acute lung injury (alveolar septal thickening, congestion, and neutrophil infiltration). Furthermore, immunoblotting showed stress kinase activation in the pancreas and lung after ligation. Although mortality was observed in the ligated group, that is consistent with severe lung injury, it requires further evaluation.

Conclusions

Bile and pancreatic duct ligation in the mouse is associated with pancreatic and pulmonary stress kinase activation and acute inflammatory changes consistent with early acute pancreatitis and acute lung injury. Our findings are important as acute lung injury increases mortality in clinical acute pancreatitis and stress kinases are established proinflammatory signal transducers.     

Cholinergic receptor induction and JNK activation in acute pancreatitis

BACKGROUND: Cholecystokinin-A (CCK-A) and cholinergic receptor pathways, capable of activating stress kinases p38 mitogen-activated protein kinase (p38(MAPK)) and cJUN N-terminal kinase (JNK), are implicated in the pathogenesis of ligation-induced acute pancreatitis in rats. As ligation-induced acute pancreatitis in rats is associated with CCK-A receptor induction and p38(MAPK) activation, and as receptor induction could amplify acinar hyperstimulation and exacerbate cell stress, we tested the hypothesis that the cholinergic M3 receptor is induced and JNK is activated in this model. METHODS: Cholinergic M3 receptor expression and JNK activation was compared in rats 1, 3, or 24 hours after sham operation or duct ligation. RESULTS: Immunoblot analysis of pancreatic homogenates showed a time-dependent increase in cholinergic M3 receptor protein, total JNK, and phospho-JNK after duct ligation. CONCLUSIONS: There is a rapid and progressive cholinergic M3 receptor induction and JNK activation in ligation-induced acute pancreatitis in rats. These findings may have significance in the mechanism of disease pathogenesis.     

Altered Serum Transforming Growth Factor-ß1 and Monocyte Chemoattractant Protein-1 Levels in Obstructive Jaundice

Impaired immune function has long been documented in patients with obstructive jaundice, and those with jaundice due to extrahepatic biliary obstruction still experience a high rate of postoperative complications and death. Transforming growth factor-ß1 (TGFß1) appears to be an important regulator of both normal and pathologic conditions in the liver. Monocyte chemoattractant protein-1 (MCP-1) is an important mediator of monocyte recruitment to inflammatory sites. We hypothesize that obstructive jaundice may alter serum TGFß1 and MCP-1 expressions in the rat and that oral bile acid or glutamine (or both) can restore the altered serum TGFß1 and MCP-1 expression in rats with obstructive jaundice. Male Sprague-Dawley rats weighing 250 to 300 g were randomized to four groups (n = 10 in each group). Group 1 underwent a sham operation with oral normal saline administration. Group 2 underwent common bile duct ligation (CBDL) with oral normal saline administration. Group 3 underwent CBDL with oral bile acid replacement. Group 4 underwent CBDL with oral glutamine administration. Animals were sacrificed after 3 days (n = 5) and 7 days (n = 5), and blood samples were collected. Serum was obtained after centrifugation for measurement of TGFß1 and MCP-1 levels by an enzyme-linked immunosorbent assay. The serum TGFß1 level was significantly elevated (p = 0.006) 3 days after CBDL. Oral glutamine administration prevented this elevation, but oral bile acid replacement did not. The serum MCP-1 level showed similar changes. After 3 days of obstructive jaundice, the TGFß1 and MCP-1 levels were altered in the rat. Oral glutamine administration, not oral bile acid replacement, was able to prevent these alterations.     

Major involvement of CD40 in the regulation of chemokine secretion from human peritoneal mesothelial cells

BACKGROUND: CD40 is a member of the tumor necrosis factor (TNF) family of receptors, whose ligand, CD154, is expressed by activated mononuclear cells. CD40 activation is a major immune regulatory pathway and is important for the regulation of chemokine and cytokine secretion. This study investigates the effect of CD40 ligation on the secretion of chemokines from human peritoneal mesothelial cells (HPMC). METHODS: We activated CD40 in HPMC along with combinations of TNF-alpha, interleukin-1 (IL-1), and interferon gamma (IFN-gamma), and evaluated the mRNA levels and protein secretion of regulated upon activation, normal T-cell expressed and secreted (RANTES), monocyte chemoattractant protein-1 (MCP-1), and IL-8. RESULTS: CD40 ligation had a small stimulatory effect on the secretion of all three chemokines, while TNF-alpha, IL-1 and IFN-gamma induced their secretion in a dose-dependent manner. The combination of CD40 ligation with either IL-1 or TNF-alpha increased chemokine secretion additively. IFN-gamma and CD40 ligation acted in synergy to induce the secretion of the mononuclear recruiting chemokines RANTES and MCP-1 (up to approximately 36-fold and approximately threefold, respectively), for which the combination of all three cytokines with CD40 ligation was extremely potent. In contrast, the secretion of the neutrophil chemoattractant IL-8, induced by CD40 ligation or by the combination of IL-1 and TNF-alpha, was reduced in the presence of IFN-gamma. CONCLUSION: In light of our data, it is reasonable to suggest that in the mononuclear phase of peritonitis, IFN-gamma and CD154, expressed by activated mononuclear cells, diminish IL-8 secretion from HPMC and thus inhibit neutrophil recruitment. At the same time, the two act in synergy to induce the secretion of RANTES and MCP-1 from HPMC. Hence, by regulating chemokine secretion, CD40 may be involved in peritonitis and in the development of late phase mononuclear predominance.     

NF-κB and chemokine-cytokine expression in renal tubulointerstitium in experimental hyperoxaluria. Role of the renin-angiotensin system

Recent evidence indicates that the renin-angiotensin system (RAS) seems to play a considerable role in the development of tubulointerstitial (TI) lesions caused by hyperoxaluria (Hox). The purpose of the present study was to evaluate the specific mechanism by which Hox involving RAS induces chemokine and cytokine expression and, therefore, renal TI damage in the ethylene-glycol (ETG) induced hyperoxaluric rat model. Sprague-Dawley rats, separated into five groups, received: G1 regular water, and G2, G3, G4 and G5 1% ETG (a precursor for oxalates) in their drinking water for 4 weeks. An angiotensin converting enzyme inhibitor, benazepril (BZ) 10 mg/kg/day, angiotensin II receptor antagonists, subtype 1 (AT1) losartan (LOS) 40 mg/kg/day and subtype 2 (AT2) PD 123,319 (PD) 10 mg/kg/day, were administered daily to G3, G4 and G5, respectively. At the end of the study, the inflammatory response to Hox was evaluated using anti-NF-B (p50), anti-IL-6, anti-MCP-1; anti-RANTES and anti-ED1 (monocytes/macrophages) in each group. In spite of the same urine oxalate levels, rats belonging to the hyperoxaluric groups treated with either BZ or LOS showed significantly (P<0.01) less TI lesions together with a lower immunoexpression of inflammatory mediators when compared with untreated hyperoxaluric animals. NF-B (p50) was increased in tubular cells in the ETG group (43.6±8.7 positive cells/mm²) and was significantly (P<0.01) reduced by LOS (11.2±4 positive cells/mm²) and even more by BZ (6.1±2.4 positive cells/mm²). There was a significant (P<0.01) correlation between NF-B (p50) positive cells and ED1 cells in the ETG group (r=0.88) and in the ETG+LOS group (r=0.92). LOS showed better control on IL-6 and MCP-1 with respect to untreated rats, while BZ showed the best control on RANTES and ED1 cells in comparison with untreated animals. Renal function was significantly (P<0.01) better preserved in BZ and LOS treated groups compared to both untreated animals and rats with PD, as indicated by creatinine clearance values. These results suggest that Hox stimulates the NF-B cascade and, therefore, induces the overexpression of inflammatory mediators like IL-6, MCP-1, and RANTES. This pathway seems to be mediated not only by AT1 but also by AT2 receptors of angiotensin II.     

Intrathecal gabapentin enhances the analgesic effects of subtherapeutic dose morphine in a rat experimental pancreatitis model

BACKGROUND: Morphine sulfate has long been used for analgesia, but clinical applications can be limited by side effects, tolerance, and potential for addiction at therapeutic doses. An agent that produces therapeutic analgesia when coadministered with low-dose morphine could have important clinical uses. The anticonvulsant agent gabapentin has been identified as having antihyperalgesic properties acting on the alpha2delta1 subunit of N-type voltage-activated calcium channels on dorsal root ganglia neurons. In this study, intrathecal gabapentin, which by itself is ineffective when administered spinally, was combined with low-dose morphine and tested in an acute bradykinin-induced pancreatitis model in rats. METHODS: An intrathecal catheter was surgically inserted into the subarachnoid space of male Sprague-Dawley rats. A laparotomy was performed for ligation and cannulation of the bile-pancreatic duct. Rats were pretreated intrathecally with artificial cerebrospinal fluid, gabapentin, morphine, or combined gabapentin and morphine 30 min before bradykinin injection into the bile-pancreatic duct. Spontaneous behavioral activity (cage crossing, rearing, and hind limb extension) was monitored before drug injection (baseline) and after bradykinin injection into the bile-pancreatic duct to assess visceral pain. RESULTS: Spinal pretreatment with up to 300 microg gabapentin alone was not effective in reducing hind limb extension in this model, but did restore some cage crossing and rearing behaviors. Spinal treatment with low-dose morphine reduced hind limb extension only. Spinal pretreatment with combined gabapentin and subtherapeutic doses of morphine sulfate resulted in restoration of all spontaneous behaviors to surgical baseline levels including elimination of hind limb extension. CONCLUSION: Combined spinal administration of gabapentin and low doses of morphine significantly reduces pain-related behaviors in this acute rat pancreatitis model, whereas these agents were ineffective when used alone in this dose range. These data suggest that the alpha2delta1 subunit of the N-type voltage-activated Ca2+ channels is involved in transmission of this visceral pain, likely through effects on primary afferent endings in the spinal cord. Thus, gabapentin may be an effective adjuvant to initial low dose spinal opioid therapy for clinical management of visceral pain.     

Pancreatic duct obstruction itself induces expression of alpha smooth muscle actin in pancreatic stellate cells

BACKGROUND: Pancreatic stellate cells (PSCs) are thought to be responsible for pancreatic fibrosis. Although fibrosis is a major characteristic of chronic pancreatitis (CP) induced by pancreatic duct obstruction, it is unclear whether pancreatic duct obstruction itself activates PSCs. METHODS: To test the hypothesis that pancreatic duct obstruction activates PSCs, clinical and experimental analyses were performed using alpha smooth muscle actin (alpha-SMA) as a marker of their activation. In clinical analysis, surgical specimens from the patients with pancreatic cancer or cancer of the papilla Vater were classified into two groups with or without duct obstruction. alpha-SMA expression was examined on these specimens, and the difference between two groups was evaluated. In animal experiment, duct ligation-induced pancreatitis was developed in rats by ligating the secondary pancreatic duct in duodenal segment, and the expression of alpha-SMA was examined. RESULTS: In clinical analysis, the specimens from the pancreas with duct obstruction (14 cases) expressed alpha-SMA significantly stronger than those from the pancreas without duct obstruction (7 cases). All specimens in the former expressed alpha-SMA, but 4 specimens from the latter did not at all (P < 0.05). In animal experiment, alpha-SMA expression was detected 7 days after the ligation and was increased on the 10th day. CONCLUSIONS:We can assume that pancreatic duct obstruction itself activates PSCs. This mechanism may play roles in the development of CP from multiple origins.     

Intrathecal Coadministration of D-APV and Morphine Is Maximally Effective in a Rat Experimental Pancreatitis Model

Background: Many studies have demonstrated that either glutamate N-methyl-d-aspartate (NMDA) receptor antagonists or opioid receptor agonists provide antinociception. Spinal coadministration of an NMDA receptor antagonist and morphine has an additive action for control of various pain states in animal models. The current study examined spinal coadministration of low doses of NMDA receptor antagonist, D-(-)-2-Amino-5-phosphonovalerate (D-APV), and [mu]-opioid receptor agonist, morphine sulfate (MS), in reducing visceral nociception using an acute bradykinin induced pancreatitis model in rats.

Methods: An intrathecal catheter was surgically inserted into the subarachnoid space for spinal drug administration in Sprague-Dawley rats. A laparotomy was performed for ligation and cannulation of the bile-pancreatic duct. Rats were pretreated intrathecally with artificial cerebrospinal fluid (aCSF), D-APV, MS, or combined administration of D-APV and MS. These treatments were given 30 min before noxious visceral stimulation with bradykinin injected through the bile-pancreatic catheter. Spontaneous behavioral activity tests, including cage crossing, rearing, and hind limb extension, were conducted before and after bradykinin injection into the bile-pancreatic duct to assess visceral nociception.

Results: Spinal pretreatment of D-APV or low doses of MS partially reduced visceral pain behaviors in this model. Pretreatments with combinations of low doses of MS (0.05-0.5 [mu]g) and D-APV (1 [mu]g) were maximally effective in returning all spontaneous behavioral activities to baseline.     

Expression and Secretion of RANTES (CCL5) in Granulomatous Calcified Tissue before and after Lipopolysaccharide Treatment In Vivo

RANTES (regulated on activation, normal T cell-expressed and secreted) is a CC chemokine appearing to be involved in the recruitment of leukocytes at inflammation sites. RANTES is produced by CD8⁺ T cells, epithelial cells, fibroblasts, and platelets. It acts in vitro in leukocyte activation and human immunodeficiency virus suppression, but its role in vivo is still uncertain. In our study, we established the involvement of RANTES in an in vivo model of chronic inflammation induced by potassium permanganate, leading to calcified granulomas. In our rat model, RANTES expression (mRNA and protein) was significantly upregulated in granulomatous tissue; RANTES expression was further increased upon i.p. injection of lipopolysaccharide (LPS), while it was kept at basal levels by dexamethasone (Dex) given 18 hours before sacrifice. LPS and Dex increased and decreased, respectively, the recruitment of mononuclear cells in granulomatous tissue compared with control granulomas from phosphate-buffered saline (PBS)-treated animals. In granuloma tissue, levels of RANTES were higher in LPS-treated rats and lower in the Dex group compared to controls. RANTES was also found in the conditioned medium of granuloma tissue from treated (LPS or Dex) and untreated (PBS) rats. When LPS was added in vitro for 18 hours, RANTES was further increased, except in the Dex group (P > 0.05). On serum analysis, RANTES levels were higher in the LPS group and lower in the Dex group compared to controls. This study shows for the first time that RANTES is produced in vivo in chronic, experimental inflammatory states, an effect increased by LPS and inhibited by Dex.     

肝肺综合征大鼠血清对肺微血管内皮细胞Akt表达的影响

目的 探讨肝肺综合征(HPS)大鼠血清对肺微血管内皮细胞(PMVECs)丝氨酸苏氨酸蛋白激酶(Akt)表达的影响.方法 健康3～4月龄SD大鼠30只,雌雄不拘,采用慢性胆管结扎法制备HPS模型.另取正常大鼠,原代培养、纯化及鉴定PMVECs.PMVECs接种于低糖DMEM培养基(10~6/,cm~2)或96孔培养板(200μl/孔),随机分为2组:对照组(C组)和HPS组,每组24皿或90孔,C组不予处理,HPS组加入HPS大鼠血清,血清终浓度为10%.于HPS大鼠血清中孵育24、48和72 h(T_(1～3))时分别采用RT-PCR法和Western blot法检测Akt_1 mRNA、Akt_2 mRNA和Akt_3 mRNA及其蛋白的表达,采用MTr法和~3H-TdR掺人法检测PMVECs增殖情况.结果 与C组比较,HPS组PMVECs增殖增强,Akt 蛋白及其mRNA表达水平上调(P<0.05);与T_1时比较,T_(2,3)时HPS组PMVECs增殖增强,Akt蛋白及其mRNA表达水平上调(P<0.05);与T_2时比较,T_3时HPS组PMVECs增殖增强,Akt蛋白及其mRNA表达水平上调(P<0.05).结论 Akt可能参与了HPS大鼠PMVECs增殖的调节.     

Intrathecal Gabapentin Enhances the Analgesic Effects of Subtherapeutic Dose Morphine in a Rat Experimental Pancreatitis Model

Background: Morphine sulfate has long been used for analgesia, but clinical applications can be limited by side effects, tolerance, and potential for addiction at therapeutic doses. An agent that produces therapeutic analgesia when coadministered with low-dose morphine could have important clinical uses. The anticonvulsant agent gabapentin has been identified as having antihyperalgesic properties acting on the [alpha]2[delta]1 subunit of N-type voltage-activated calcium channels on dorsal root ganglia neurons. In this study, intrathecal gabapentin, which by itself is ineffective when administered spinally, was combined with low-dose morphine and tested in an acute bradykinin-induced pancreatitis model in rats.

Methods: An intrathecal catheter was surgically inserted into the subarachnoid space of male Sprague-Dawley rats. A laparotomy was performed for ligation and cannulation of the bile-pancreatic duct. Rats were pretreated intrathecally with artificial cerebrospinal fluid, gabapentin, morphine, or combined gabapentin and morphine 30 min before bradykinin injection into the bile-pancreatic duct. Spontaneous behavioral activity (cage crossing, rearing, and hind limb extension) was monitored before drug injection (baseline) and after bradykinin injection into the bile-pancreatic duct to assess visceral pain.

Results: Spinal pretreatment with up to 300 [mu]g gabapentin alone was not effective in reducing hind limb extension in this model, but did restore some cage crossing and rearing behaviors. Spinal treatment with low-dose morphine reduced hind limb extension only. Spinal pretreatment with combined gabapentin and subtherapeutic doses of morphine sulfate resulted in restoration of all spontaneous behaviors to surgical baseline levels including elimination of hind limb extension.     

Lipoxin A4 inhibits connective tissue growth factor-induced production of chemokines in rat mesangial cells

Connective tissue growth factor (CTGF) is involved in mitogenesis, matrix production, and chemotaxis in mesenchymal cells. The effects of CTGF on the production of chemokines remain unclear. The present studies investigate the regulatory role of CTGF in the production of fractalkine, monocyte chemoattractant protein-1 (MCP-1), and RANTES (regulated upon activation, normal T cell expressed and secreted) in cultured mesangial cells of rats, and the modulatory effects of lipoxin A(4) (LXA(4)) on actions of CTGF. CTGF enhanced the mRNA expression and protein release of fractalkine, MCP-1, and RANTES, the expression of phospho (P)-p42/44 mitogen-activated protein kinase (MAPK), P-phosphoinositide 3-kinase (PI3-K), P-Akt, and activity of nuclear factor-kappaB (NF-kappaB) in mesangial cells. P-p42/44 MAPK blockade inhibited the CTGF-induced expression of P-p42/44 MAPK but not NF-kappaB, and partially decreased the levels of the above chemokines in supernatants. P-PI3-K blockade downregulated the CTGF-stimulated expression of P-PI3-K, P-Akt, and NF-kappaB but not P-p42/44 MAPK, and partially decreased the release of the above chemokines. NF-kappaB blockade abrogated the CTGF-activated NF-kappaB and partially decreased the secretion of the above chemokines. LXA(4) dose-dependently inhibited the CTGF-stimulated mRNA expression and protein release of the above chemokines, and the expression of P-p42/44MAPK, P-PI3-K, P-Akt, and NF-kappaB. In conclusion, these results demonstrate that CTGF induces production of fractalkine, MCP-1, and RANTES via the p42/44 MAPK-, PI3-K/Akt-, and NF-kappaB-dependent signal pathway, and LXA(4) downregulates the above effects of CTGF on rat mesangial cells.     

Characterization of K-ras gene mutations in association with mucinous hypersecretion in intraductal papillary-mucinous neoplasms

Background/Purpose Intraductal papillary-mucinous neoplasms (IPMNs) of the pancreas have a favorable prognosis. However, invasive ductal carcinomas of the pancreas show a rapid progression. The aim of this study was to investigate gene mutations in pure pancreatic juice from IPMN patients and to define these genetic mutations in relation to the histopathological and clinical features of IPMNs. Methods Twenty-two patients with IPMN, 21 patients with ductal carcinoma, and 20 patients with normal pancreas or chronic pancreatitis were recruited for this study. We measured the main pancreatic duct’s largest diameter and the maximum size of a dilated branch was assessed by ultrasonography or endoscopic ultrasonography. Pure pancreatic juice was collected and was investigated for K-ras, p16, and p53 mutations. Results Mutant K-ras gene was detected in 13 of the 22 patients (59.1%) with IPMNs. Different kinds of mutations were detected in the same patient in 4 cases. In the 13 patients with mutant K-ras gene, the diameter of the most dilated part of the main pancreatic duct was 2–8 mm (average, 4.5 mm) and in 7 patients with wild-type K-ras gene, the diameter was 2–5 mm (average, 2.7 mm). There was a significant difference in the diameter of the main pancreatic duct between patients with and without the mutant K-ras gene (P = 0.0323). Conclusions The incidence of K-ras mutation may be associated with the hypersecretion of mucin.     

灌注联合胰胆管结扎诱导大鼠急性胰腺炎

目的 模拟急性胆源性胰腺炎的发病条件,制作一种符合临床特点的大鼠急性坏死性胰腺炎模型.方法 设计大鼠胰胆管单扎和双扎两种结扎方法,测压并用2%甘氨脱氧胆酸(GDCA)以35 cm H2O(1 cm H2O=0.098 kPa)压力恒压灌注5 min,8、16、24 h剖杀,观察急性胰腺炎的发生情况.结果 单扎组胆胰管压力为:(20.60±1.51)cm H2O,双扎组为:(29.37±0.87)cmH20.两组均诱导急性胰腺炎,于24 h表现出坏死性胰腺炎特征.病理学评分显示,随时间进程,胰腺炎逐渐加重(P＜0.01).在各时间点,胆胰管双扎组炎症重于单扎组(P＜0.01).结论 恒压灌注2%GDCA联合胰胆管单扎和双扎均可诱导出大鼠急性坏死性胰腺炎;胰管压力及其持续时间与急性胰腺炎发生、发展密切相关.

Abstract：

Objective To establish a new acute necrotizing pancreatitis model in rats. Methods We designed single pancreatic bile duct ligation and double pancreatic bile duct ligation in rats, combined with retrogradely infusing 2% glycodeoxycholic acid ( GDCA), to test duct pressure and observe the severity of acute pancreatitis at 8, 16 and 24 h, respectively. Results In two groups, the duct pressures were (20. 60 ± 1.51 ) cm H2O and (29. 37 ±0. 87) cm H2O, respectively. Both of the two methods could induce typical acute necrotizing pancreatitis at 24 h, the severity of which progressively developed with time course(P ＜0. 01 ), at each time point, the severity of double duct ligation group was higher than single duct ligation group ( P ＜ 0. 01 ). Conclusion Retrogradely infusing 2% GDCA with constant pressure,combined with the two methods of pancreatic bile duct ligation, coude induce clinically relevant acute necrotizing pancreatitis in rats; the pancreatic duct pressure and its duration might be closely related to the arising and developing of acute pancreatitis.