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Query: UMLS:C0001339 (acute pancreatitis)
 10,593 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Acute pancreatitis was induced by ligating the opossum common biliopancreatic duct immediately proximal to its entry into the duodenum, and macroscopic as well as microscopic changes were evaluated during the subsequent 24 hours. Transient pancreatic edema and progressive hyperamylasemia were noted within 6 hours of pancreatic and bile duct ligation. Light microscopic evidence of pancreatic injury including acinar cell necrosis, hemorrhage, fat necrosis, and inflammatory cell infiltration was noted within 12 hours of duct obstruction. Electron microscopic changes included massive dilatation of the rough endoplasmic reticulum and disruption of the apical plasmalemma of acinar cells during the initial 3 hours. These observations indicate that pancreatic and bile duct ligation in the opossum results in the rapid (less than 24 hours) appearance of changes consistent with acute hemorrhagic and necrotizing pancreatitis and that the initial lesion in this model of experimental pancreatitis involves acinar cells.
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PMID:Acute necrotizing pancreatitis in the opossum: earliest morphological changes involve acinar cells. 846 17

A new protein was purified from the pancreatic juice of rats with acute pancreatitis. That protein, not detectable in control animals, was called "pancreatitis-associated protein." It was first observed 6 hours after induction of experimental pancreatitis with taurocholate or cerulein, reached maximal levels of 45 micrograms/mg protein in zymogen granules and 1.8 micrograms/mg protein in pancreatic tissue during the acute phase (48 hours), and disappeared during recovery (day 5). It was never detected in spleen, liver, kidney, heart, or lung. The detection limit of the assay system was 12 ng/mg protein, so that pancreatitis-associated protein levels increased at least 100-fold in pancreatic tissue during the acute phase. The molecular weight (12,000) and isoelectric point (8.2) were determined by two-dimensional gel electrophoresis. Subcellular fractionation and immunoelectron microscopy showed that the protein was synthesized on the rough endoplasmic reticulum and stored in zymogen granules before being secreted, similar to other pancreatic secretory proteins. Immunoblotting and two-dimensional gel electrophoresis revealed that the same protein was synthesized upon induction of pancreatitis by cerulein infusion, by retrograde injection of bile acids, or pancreatitis induced by pancreatic surgery. The pancreatitis-associated protein is therefore an acute-phase protein that differs from other proteins of that family because of its exocrine nature.
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PMID:Characterization of a rat pancreatic secretory protein associated with pancreatitis. 170 29

A membrane-bound system through which secretory and lysosomal proteins travel in a vectorial fashion is essential for the preserved integrity of pancreatic acinar cells. This system is composed of an ordered array of compartments, such as the rough endoplasmic reticulum, the Golgi complex, lysosomes, and secretory granules. As a principle, in acute pancreatitis the final steps of this transport seem to be disturbed. Caerulein-induced pancreatitis is a valuable experimental model for studying altered intracellular transport, and compartmentation of lysosomal and digestive enzymes. The formation of enlarged secretory vacuoles containing lysosomal and digestive enzymes is paralleled by the activation of lysosomes and degradation of cellular organelles in autophagosomes. On the level of secretory and autophagic vacuoles, activation of serine proteases occurs, which in addition to increasing lysosomal enzyme activities can represent the initial stage for acinar cell destruction and the development of pancreatitis.
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PMID:Mechanism of acute pancreatitis. Cellular and subcellular events. 174 43

In the pathogenesis of acute pancreatitis, the events and mechanisms increasing the digestibility of the pancreatic acinar cells are widely unknown. Therefore, the possible contribution of a disturbed energy supply (provoked by anoxia or partial uncoupling) to the induction of autodigestion was studied in experiments on acinar cells isolated from the pancreas. During incubation viability, respiration under normal and maximally stimulated conditions, and trypsin-inhibiting capacity (TIC) of these cells were determined. With increasing duration of anoxia, the portion of surviving cells was strongly diminished, and the number of cells with blebs and vesicularly transformed endoplasmic reticulum was increased. Although the endogenous respiration was not influenced up to 1.5 h of anoxia, 30 min of anoxia substantially decreased the capacity of oxidative energy production. The survival curves were characterized by a self-accelerating course of cell destruction. The alteration of the cellular energy metabolism found its reflection in the decreased TIC of the cells.
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PMID:Influence of anoxia, reoxygenation, and uncoupling on survival, respiration, and trypsin-inhibiting capacity of isolated pancreatic acinar cells. 175 30

Hypercalcemia has been associated with acute pancreatitis clinically and in the experimental animal. We studied the pancreatic ultrastructure in acute experimental hypercalcemia. Anesthetized cats (Pentobarbital, 0.55 mg/kg) received Ca++ (Calcium-Gluconate: 0.6 mmol/kgh; n = 4), K+ (KCl: 1.1 mmol/kgh; n = 4) or NaCl (0.9%; n = 4) locally through retrograde infusion into the splenic artery. Biopsies for electron microscopy (EM) were taken at three hours. Eight cats received intravenous Ca++ (0.6 mmol/kgh, 0.3 mmol/kgh after three hours) or NaCl (0.9%) for 12 hours. Biopsies were collected in two animals in three-hour intervals, and in all animals at twelve hours. After local calcium infusion necrotizing pancreatitis was seen macroscopically in the body of the pancreas. Biopsies for EM showed acinar cell necrosis, hydrops of nuclei and mitochondria and needle-like precipitates in the cytoplasma in the center of calcium perfusion. Biopsies taken from the peripheral region of the macroscopically altered tissue revealed desorganisation of the acinar polarisation and the endoplasmic reticulum, with zymogen granules appearing in the basolateral cell-portion. After intravenous calcium administration no macroscopical changes were seen. In EM acinar cells showed dilatation and proliferation of the golgi apparatus and increased number of condensing vacuoles indicating stimulation. Again, disorganisation of acinar cell polarisation was present. Control animals treated with K+ or NaCl showed normal pancreatic ultrastructure. The morphological changes after calcium infusion indicate direct damage to the acinar cell. Our results suggest that hypercalcemia induced pancreatitis could originate in the acinar cell.
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PMID:[Electron microscopy of the exocrine pancreas in experimental acute hypercalcemia]. 186 39

Previous studies using the isolated ex vivo perfused canine pancreatitis preparation showed that during a 4-hour perfusion pancreatitis (edema, weight gain, hyperamylasemia) can be induced by four different stimuli. The stimuli include the intra-arterial infusion of oleic acid (FFA), a 2-hour period of ischemia before perfusion (ISCH), partial obstruction of the pancreatic duct with secretin stimulation (POSS), and the intra-arterial infusion of cerulein at supramaximal doses (CER). In the present study, changes in high-energy phosphate metabolism, as determined by nuclear magnetic resonance spectroscopy, and changes in cellular structure, determined by light and electron microscopy, were documented for all four models of acute pancreatitis. The control preparations remained stable for the 4-hour perfusion period, with no decrease in adenosine triphosphate (ATP) levels. In the FFA preparations, ATP decreased to 36% of baseline levels during the 4-hour perfusion (p less than 0.001). In the ISCH preparations, ATP decreased to undetectable levels during the 2-hour period of ischemia, but recovered rapidly and remained at baseline levels during the perfusion. ATP levels remained stable in the remaining two models of pancreatitis (POSS, CER). Microscopy demonstrated that the initial injury was located chiefly in the capillaries (swollen endothelium, intravascular thrombi) in the FFA and ISCH preparations. In the POSS and CER preparations, capillary changes were minimal and the injury was located chiefly in the acinar cells (swollen endoplasmic reticulum, zymogen granule depletion, vacuolization). The POSS preparations also showed striking dilation of centroacinar lumens reflecting duct obstruction. In additional studies it was shown that the ATP decline in the FFA preparations could be significantly reduced by pretreatment with free radical scavengers. The morphologic changes could be reduced by free radical scavengers in the FFA and ISCH preparations. Any amelioration of morphologic injury in the POSS preparations was obscured by dilatation of centroacinar lumens in both treated and untreated groups. The morphologic changes in the CER preparations were reduced by treatment with a cholecystokinin inhibitor.
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PMID:Changes in high-energy phosphate metabolism and cell morphology in four models of acute experimental pancreatitis. 200 16

The early lesions induced in the pancreas of dogs by the intraductal injection of bile-trypsin were studied. Histological, histochemical and electron microscopic techniques were used. The primary lesions analyzed thirty three minutes after the induction of pancreatitis consisted in cell alterations, blood stasis and oedema. At first, the affected acinar cells showed enlargement of the rough endoplasmic reticulum cisternae, later they were disrupted and then appeared vesicles with ribosomes adhering to the external surface. Mitochondria were swelled and showed cristae disrupted which finally appeared destroyed. The zymogen granules lost density, decreased in size and number and later disappeared, Ducts maintained the normal structure and their cells were still observed in areas where the tissue was greatly destroyed. the results obtained suggest that: 1) The experimental acute pancreatitis induced by bile-trypsin is characterized by primary and severe damage in the acinar cells, with secondary ischemia due to stasis and intravascular coagulation. 2) Cellular rests and probably endogenous enzymes invade the periacinar spaces, then would penetrate into the vascular system producing the generalization of lesions.
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PMID:[Acute pancreatitis induced by bile trypsin: structural and ultrastructural study]. 227 10

In the present study fine structural changes of acinar zymogen granules were investigated in human acute pancreatitis. Pancreatic tissue was obtained at surgery from 6 patients, prepared for ultrastructural analysis, and stained immunocytochemically for trypsinogen. Stereological parameters of zymogen granules were evaluated. The density of the immunocytochemical labelling for trypsinogen was estimated over zymogen granules, the rough endoplasmic reticulum, Golgi apparatus and the acinar lumina. In acute pancreatitis the number of zymogen granules was diminished and their size reduced. The density of the labelling for trypsinogen was unchanged over zymogen granules but showed a significant reduction over the rough endoplasmic reticulum, Golgi apparatus, and the acinar lumina. In general the integrity of zymogen granules was well preserved. Focally degenerative changes of zymogen granules and large autophagosomes were observed. From the immunogold labelling a disturbance of enzyme synthesis and secretion was suggested. Evidence is given that a disruption of the zymogen granule membranes and a fusion with lysosomal bodies might contribute to the pathogenesis of human acute pancreatitis.
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PMID:Immunocytochemical and morphometric analysis of acinar zymogen granules in human acute pancreatitis. 250 Jul 66

This paper attempts to demonstrate the influence of gallstones, from different locations, on ultrastructural changes in pancreatic acinar cells. Forty-two gallstone patients with no record of clinical pancreatitis are the subjects of this study. Of these patients, 14 have cholecystolithiasis, 14 have choledocholithiasis, and 14 have primary hepatolithiasis. The findings reveal the following ultrastructural alterations of the pancreatic acinar cells: dilation of the rough endoplasmic reticulum, accumulation of lipid droplets, an increase of autophagic vacuoles, residual bodies and myelin figures, alteration of electron density of zymogen granules, and alteration of mitochondria. All these ultrastructural changes are similar to those of clinical acute pancreatitis. With three locations of calculi, these different kinds of gallstones have a similar affect on the fine structure of pancreatic acinar cells, and these changes occur regardless of the size of the common bile duct and the biochemical data. This suggests that irrespective of the location of the gallstones, subclinical cellular injury to acinar cells is caused.
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PMID:Effect of gallstones on pancreatic acinar cells. An ultrastructural study. 322 32

Trypsin, phospholipase A2, lysolecithin or non-ionic detergent polyoxyethylene p-t-octyl phenol solutions were injected into the rat biliopancreatic duct. Histological and ultrastructural changes in the gland were studied 15 min and 3 h after the injections. The rough surfaced endoplasmic reticulum disintegrated in two ways: (1) the endoplasmic reticulum in the cell periphery was vesiculated but ribosomes were well preserved at 15 min, and (2) large, round membranous structures appeared in apical cytoplasm at 3 h. Zymogen granules disintegrated in the second type, which possibly represents autodigestion. Both types of injury lead ultimately to structureless necrosis. Lesions induced by phospholipase A2 and lysolecithin were identical. Trypsin-induced damage developed slowly and the two phases of endoplasmic reticulum disintegration were not sharply separable. Lesions caused by polyoxyethylene p-t-octyl phenol were variable at 15 min, but at 3 h the type 2 injury described above was observed. It was concluded that although the initial damage in pancreatic acinar cells may vary, necrotic changes are similar despite the injected material at the later time interval. During acute pancreatitis, the acinar cell necrosis is most probably due to the action of lysolecithin produced by the activation of phospholipase A2.
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PMID:Experimental pancreatitis in the rat. Light and electron microscopical observations on early pancreatic lesions induced by intraductal injection of trypsin, phospholipase A2, lysolecithin and non-ionic detergent. 612 35


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