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Query: UMLS:C0149521 (chronic pancreatitis)
 7,199 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In chronic pancreatitis the exocrine pancreatic tissue is replaced by extracellular matrix deposits from fibroblasts. We have stimulated fibrogenesis in the pancreas by inducing a single episode of cerulein pancreatitis (10 microg/kg/h for 12 h). We have used a spectrophotometrical assay to measure the tissue hydroxyproline content and immunohistochemistry to study the transient deposition of extracellular matrix in the pancreas. We have investigated whether a potent prolyl 4-hydroxylase inhibitor (HOE-077) can influence the deposition of extracellular matrix in the pancreas. Three days after the induction of the pancreatitis we found the maximum increase in pancreatic hydroxyproline content (by 63%), the maximum decrease in total protein content and amylase activity (by -39 and -86%, respectively), as well as a significant increase in DNA content and the deposition of interstitial collagen fibers on electron microscopy. By immunohistochemistry the largest expansion of extracellular matrix components was found for fibronectin. HOE 077, regardless of the concentration administered, failed to affect any of these parameters. We conclude that the induction of a single episode of cerulein pancreatitis and the serial determination of pancreatic hydroxyproline content represents a simple method to induce and monitor experimental fibrogenesis in the pancreas. Prolyl 4-hydroxylase inhibition did not affect the course of extracellular matrix deposition in the pancreas.
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PMID:Failure of a prolyl 4-hydroxylase inhibitor to alter extracellular matrix deposition during experimental pancreatitis. 901 10

The pathogenesis of chronic pancreatitis (CP) has been debated as to whether it is a de novo process or the consequence of acute pancreatitis (AP). We investigated whether recurrent AP in rats leads to CP, by sequential morphological and biochemical studies. Thirty male Wistar rats were fed a choline-deficient diet with intraperitoneal ethionine injections twice daily at a dose of 60 mg/100 g body weight twice weekly, and six rats were killed at 4, 6, and 8 weeks; the remaining 12 rats, followed without further treatment, were killed at 12 and 16 weeks. The pancreata from study and control groups were examined by histology, immunohistochemistry, and bio- and immunoassays. Histologically, moderate to severe intra- and perilobular fibrosis and other CP-like lesions appeared maximally at 8 weeks. Immunohistochemically, the earliest extracellular matrix change was strong fibronectin staining at 4 weeks, with a progressive increase to 8 weeks. Collagens I and III came to show strong, and collagen IV moderate, interstitial staining at 6-8 weeks. These morphological changes, however, returned to nearly normal at 16 weeks. Prolyl hydroxylase was significantly elevated at 4 and 6 weeks and normalized after 8 weeks, with no significant change in collagenase. In conclusion, our results suggest that even severe CP-like lesions induced by recurrent AP are reversible in the absence of persistently elevated prolyl hydroxylase and/or suppressed collagenase. The mechanism regulating these changes remains to be studied further.
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PMID:Does recurrent acute pancreatitis lead to chronic pancreatitis? Sequential morphological and biochemical studies. 916 78

Prolyl hydroxylase is a key enzyme in collagen synthesis, and tissue inhibitor of metalloproteinase (TIMP) is known to suppress collagenolytic enzymes. To see whether the levels of these two enzymes in serum and human pure pancreatic juice (PPJ) are good indicators of pancreatic fibrosis in chronic pancreatitis (CP), we examined 15 controls, 14 alcoholics without evident pancreatic diseases (7 current drinkers and 7 former drinkers), and 19 patients with CP. Levels of the two enzymes were determined by a sandwich enzyme immunoassay method. TIMP-1 levels in PPJ were significantly higher in patients with CP than in controls and alcoholics, with overlap in only a few exceptional patients. A significant inverse correlation between TIMP-1 and bicarbonate output in PPJ was observed. Prolyl hydroxylase levels in PPJ, in contrast, were significantly higher in current drinkers than in patients with CP, controls, and former drinkers, with overlap in only a few exceptional patients with relapsing CP. Identical results were obtained even when the enzyme levels were expressed as nanograms per milligram of protein. Serum levels of prolyl hydroxylase and TIMP-1 showed no significant differences among controls, current alcoholics, former alcoholics, and patients with CP. These results indicate that the raised level of TIMP-1 in PPJ, unlike that of prolyl hydroxylase, is a good indicator of pancreatic fibrosis in CP.
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PMID:Prolyl hydroxylase and tissue inhibitor of metalloproteinase in pure pancreatic juice in patients with chronic pancreatitis. 959 9

Little is known about the pathogenesis of fibrosis in chronic pancreatitis. To reach a better understanding of this problem, we investigated the immunolocalizations of type IV collagen (Col-IV) and laminin around pancreatic ducts, and those of matrix metalloproteinase-2,9 (MMP-2,9), tissue inhibitors of metalloproteinase-1,2), and transforming growth factor-beta 1 (TGF beta 1) at the ductal epithelia in chronic pancreatitis. This study included 20 surgical specimens of fibrotic pancreas from patients with chronic pancreatitis and five normal samples from autopsy cases. Immunostaining was performed by the streptavidin-biotin method after antigen retrieval. We evaluated the staining patterns and the percentage of positive cells of each antigen. In chronic pancreatitis, the immunostainings of Col-IV and laminin along the basement membrane (BM) of pancreatic ducts were disrupted in 11 (55%) of 20 and eight (40%) of 20, respectively, whereas no disruption was detected in normal pancreas. Positive immunostainings for MMP-2, MMP-9, TIMP-1, and TIMF-2 in ductal epithelia were 15 (75%) of 20, five (25%) of 20, four (20%) of 20, and 10 (50%) of 20, respectively, whereas no immunostaining was seen in normal pancreas. The staining intensity of MMP-2 in ductal epithelia was associated with the staining intensity of Col-IV around the pancreatic ducts. Also, the staining intensity of MMP-2 was progressively increased in proportion to the staining intensity of TGF beta 1. These findings suggest that TGF beta 1 induced in pancreatic duct cells also induced MMP-2 in an autocrine or paracrine manner, and that this MMP-2 decomposed Col-IV of the BM of pancreatic ducts in chronic pancreatitis.
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PMID:Immunohistochemical study of transforming growth factor-beta 1, matrix metalloproteinase-2,9, tissue inhibitors of metalloproteinase-1,2, and basement membrane components at pancreatic ducts in chronic pancreatitis. 982 Nov 84

The purpose of this study was to investigate the morphological changes in the islets observed in a new chronic pancreatitis model with diabetes induced by repetition of cerulein injection plus water-immersion stress in rats. The rats of this model were treated with water-immersion stress for 5 h and two intraperitoneal injections of 20 micrograms/kg body weight of cerulein once a week for 16 weeks. In the stress and cerulein group, 62% of the islets exhibited infiltration of mononucleated cells, and/or peri- and intrainsular fibrosis. On immunohistochemical study, some islets showed reduced density of the insulin immunoreactivity. The glucagon-producing cells decreased in number. With electron microscopy, various endocrine changes were observed, mainly in the B cells. The changes included scattered debris damage with reduction of secretary granules, and vesiculation of the endoplasmic reticulum. Numerous fibroblasts clustered around the islets, and proliferating collagen fibers invaded the islets. The microvascular changes consisted of bleeding and damage to the endothels. In the pancreas treated with stress alone or cerulein alone, significant endocrine damage was not observed. In conclusion, chronic repetitive treatment with stress and cerulein, together with poor islet circulation due to fibrosis and vascular changes, resulted in the endocrine cellular damage.
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PMID:Morphological study of pancreatic endocrine in an experimental chronic pancreatitis with diabetes induced by stress and cerulein. 1044 84

Significant fibrosis and acinar atrophy are characteristics of chronic pancreatitis; however, because of the lack of a reproducible model, early phases of these changes are poorly understood. We have developed a model of severe hyperstimulation and obstruction pancreatitis (SHOP) to better define the mechanisms of early pancreatic fibrogenesis. Sprague-Dawley rats were used and SHOP was induced by complete pancreatic duct obstruction and daily cerulein hyperstimulation (50 microg/kg intraperitoneally). Animals were killed at 24, 48, 72, and 96 hours. Control animals underwent sham operation and received no cerulein. Pancreata were prepared for hematoxylin and eosin and sirius red (collagen-specific) staining and for hydroxyproline assay (measure of total collagen content). We found moderate amounts of edema and inflammation but minimal parenchymal necrosis. Significant loss of acinar cell mass was noted by 48 hours, and normal acinar cells were essentially absent by 96 hours. Tissue collagen content increased with time and large amounts of interstitial collagen were detected by 72 hours. In conclusion, SHOP is a novel model of early pancreatic fibrosis associated with minimal necrosis and a significant decrease in acinar cell mass, making it an ideal model to study the early cellular mechanisms of pancreatic fibrogenesis.
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PMID:Characterization of a novel model of pancreatic fibrosis and acinar atrophy. 1048 95

The prevalence and the mechanisms of hepatic fibrosis in chronic alcoholic pancreatitis remain uncertain. The aim of this study was to investigate the fibrogenic activity of the liver in patients with chronic pancreatitis and its relation with either the alcohol or cholestasis. Liver biopsies were obtained from 16 patients with chronic pancreatitis at the time of surgery and from 10 organ donors. Samples were processed for histologic examination to assess the presence and extent of fibrosis, inflammatory reactions, and cholestasis- and alcohol-related lesions. In other samples, the collagen content was measured by morphometry, and prolylhydroxylase activity was determined. Liver-function tests, ultrasonography, and endoscopic retrograde cholangiopancreatography were performed before surgery in all the patients. Of patients with chronic pancreatitis, 75% had significantly greater hepatic fibrosis and prolylhydroxylase activity than the control group. Moreover, prolylhydroxylase activity in patients with chronic pancreatitis was higher in those with cholestasis or partial obstruction of the common bile duct than in those without cholestasis or partial obstruction of the common bile duct. Both the fibrogenic activity and the collagen content in the livers of patients with chronic alcoholic pancreatitis are significantly increased, even in those without histologic lesions, and these alterations may be secondary to a partial occlusion of the common bile duct.
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PMID:Hepatic fibrogenic activity in chronic alcoholic pancreatitis. 1050 58

The mechanisms of pancreatic fibrosis are poorly understood. In the liver, stellate cells play an important role in fibrogenesis. Similar cells have recently been isolated from the pancreas and are termed pancreatic stellate cells. The aim of this study was to determine whether pancreatic stellate cell activation occurs during experimental and human pancreatic fibrosis. Pancreatic fibrosis was induced in rats (n = 24) by infusion of trinitrobenzene sulfonic acid (TNBS) into the pancreatic duct. Surgical specimens were obtained from patients with chronic pancreatitis (n = 6). Pancreatic fibrosis was assessed using the Sirius Red stain and immunohistochemistry for collagen type I. Pancreatic stellate cell activation was assessed by staining for alpha-smooth muscle actin (alphaSMA), desmin, and platelet-derived growth factor receptor type beta (PDGFRbeta). The relationship of fibrosis to stellate cell activation was studied by staining of serial sections for alphaSMA, desmin, PDGFRbeta, and collagen, and by dual-staining for alphaSMA plus either Sirius Red or in situ hybridization for procollagen alpha(1) (I) mRNA. The cellular source of TGFbeta was examined by immunohistochemistry. The histological appearances in the TNBS model resembled those found in human chronic pancreatitis. Areas of pancreatic fibrosis stained positively for Sirius Red and collagen type I. Sirius Red staining was associated with alphaSMA-positive cells. alphaSMA staining colocalized with procollagen alpha(1) (I) mRNA expression. In the rat model, desmin staining was associated with PDGFRbeta in areas of fibrosis. TGFbeta was maximal in acinar cells adjacent to areas of fibrosis and spindle cells within fibrotic bands. Pancreatic stellate cell activation is associated with fibrosis in both human pancreas and in an animal model. These cells appear to play an important role in pancreatic fibrogenesis.
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PMID:Activation of pancreatic stellate cells in human and experimental pancreatic fibrosis. 1051 91

We have recently identified and characterized pancreatic stellate cells (PSC) in rats and humans (Gastroenterology 1998, 15:421-435). PSC are suggested to represent the main cellular source of extracellular matrix in chronic pancreatitis. Now we describe a paracrine stimulatory loop between human macrophages and PSC (rat and human) that results in an increased extracellular matrix synthesis. Native and transiently acidified supernatants of cultured macrophages were added to cultured PSC in the presence of 0.1% fetal calf serum. Native supernatants of lipopolysaccharide-activated macrophages stimulated the synthesis of collagen type I 1.38 +/- 0.09-fold of control and c-fibronectin 1.89 +/- 0.18-fold of control. Transiently acidified supernatants stimulated collagen type I and c-fibronectin 2.10 +/- 0.2-fold and 2.80 +/- 0.05-fold of control, respectively. Northern blot demonstrated an increased expression of the collagen-I-(alpha-1)-mRNA and fibronectin-mRNA in PSC 10 hours after addition of the acidified macrophage supernatants. Cell proliferation measured by bromodeoxyuridine incorporation was not influenced by the macrophage supernatants. Unstimulated macrophages released 1.97 pg TGFbeta1/microgram of DNA over 24 hours and lipopolysaccharide-activated macrophages released 6.61pg TGFbeta1/microgram of DNA over 24 hours. These data together with the results that, in particular, transiently acidified macrophage supernatants increased matrix synthesis, identify TGFbeta as the responsible mediator. In conclusion, our data demonstrate a paracrine stimulation of matrix synthesis of pancreatic stellate cells via TGFbeta1 released by activated macrophages. We suggest that macrophages might play a pivotal role in the development of pancreas fibrosis.
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PMID:Lipopolysaccharide-activated macrophages stimulate the synthesis of collagen type I and C-fibronectin in cultured pancreatic stellate cells. 1055 Mar 31

The role of repetitive acute injury in the pathogenesis of chronic pancreatitis remains unknown. To determine if repetitive injury induced by pancreatic hyperstimulation would reproduce the characteristic features of human chronic pancreatitis, acute reversible pancreatic injury was induced in mice by twice weekly cerulein treatment, 50 microg/kg/hr x 6 hr, for 10 weeks. Procollagen alpha1(I) mRNA was markedly increased by week 2. Sirius red staining of interstitial collagen demonstrated progressive accumulation of extracellular matrix surrounding acinar units and in interlobular spaces. Atrophy, transdifferentiation of acinar units to ductlike tubular complexes, and dilatation of intraacinar lumina also developed. Electron microscopy demonstrated the presence of stromal cells in areas of fibrosis with morphologic characteristics of pancreatic stellate cells. These findings demonstrate that, in a murine model, repetitive acute injury to the pancreas by hyperstimulation can reproduce the major morphological characteristics of human chronic pancreatitis.
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PMID:Repetitive self-limited acute pancreatitis induces pancreatic fibrogenesis in the mouse. 1075 32


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