Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C1389183 (autodigestion)
 317 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The study was undertaken to investigate the effect of phospholipase A2 (PLA2) on the viability of isolated pancreatic acinar cells (PACs) and its possible synergy with ethanol. The survival of PACs may be reduced by PLA2 in a dose-dependent manner. In the presence of 0.25 microgram PLA2.(10(6) cells)-1, all cells died within less than 4 h of incubation at 37 degrees C. A quantity of 180 mM ethanol, which alone was not lethal for PACs, increased the rate of cell death induced by PLA2 at a certain concentration of this enzyme. The present results imply that (1) PLA2 is able to damage PACs in the absence of additional substrates, and (2) at an appropriate activity of PLA2, ethanol may amplify the toxic effects of this lytic enzyme and force autodigestion of the pancreas.
 ...
PMID:Effect of phospholipase A2 and ethanol on the survival of acinar cells isolated from the rat pancreas. 139 35

Acute pancreatitis (AP) is believed to result from intraparenchymal activation of trypsin and other digestive enzymes within the pancreas followed by autodigestion of the gland. Gabexate mesilate (FOY), a synthetic guanidino acid ester exhibiting potent and versatile inhibitory actions on a number of proteinases (e.g., trypsin, kallikrein, C1-r, C1 esterase, plasmin, thrombin, phospholipase A2), was examined for its ability to protect the rat pancreas against development of AP induced by pharmacological doses of ceruletide (CRT). Rats were i.v. infused for 6 h with either CRT (5 micrograms/kg/h) or CRT + FOY (50 mg/kg/h). In FOY-treated rats the serum amylase and trypsinogen concentrations were reduced by 60 and 80%, respectively, compared to rats infused with CRT alone. Histologically, the extent of acinar cell vacuolization in the pancreas was significantly reduced and interstitial edema, although not assessed by quantitative morphometric techniques, appeared to be qualitatively lessened in the FOY-treated rats. The ability of FOY to inhibit significantly AP produced by supramaximal doses of CRT, coupled with its inhibitory properties on components of the coagulation and complement cascades, stress the importance of continued research on this compound as a potential therapeutic agent for treatment of AP and its systemic sequelae.
 ...
PMID:Gabexate mesilate (FOY) protects against ceruletide-induced acute pancreatitis in the rat. 244 41

Intrapancreatic activation of proteases is believed to play a major role in the pathogenesis of acute necrotizing pancreatitis. Several authors have questioned, however, the central role of trypsin in autodigestion of the pancreas. To clarify the direct effects of pancreatic enzymes and other related factors on acinar cells, we used the model of isolated pancreatic acini. Acini were prepared from male Wistar rats by collagenase digestion. Protein synthesis was measured by incubation of acini with [35S]methionine. Acini were resuspended thereafter in fresh buffer and further incubated for 30-90 min under various conditions [e.g., with pancreatic homogenates, ascites (from rats with pancreatitis induced by sodium taurocholate), pure pancreatic enzymes, and other factors]. The percentage of release of newly synthesized proteins into the culture medium was regarded as a biochemical parameter of cellular integrity. A morphologic score of cellular integrity was obtained via light microscopic evaluation of acini at the end of the various incubations by measuring the degree of cell lysis, loss of cell granules, ballooning, formation of vacuoles, and karyopyknosis. When normal [35S]methionine-labeled pancreatic acini were incubated with various factors, the percentage of release of labeled proteins into the medium was as follows: incubation with HEPES/Ringer's buffer, 1.8%; hemorrhagic pancreatic ascites, 3.8%; pancreatic homogenates, 2.0%; lipase, 1.8%; phospholipase A2, 3.0%; phospholipase A2 + lecithin, 3.2%; trypsin, 2.5%; 5% olive oil, 1.8%; ascites + olive oil, 78.3%; ascites + homogenized epididymal fat, 79.9%; lipase + olive oil, 32.0%; pancreatic homogenates + olive oil, 28.0%; diolein, 2.65%; and oleic acid, 62.9%. The cellular release of radiolabeled proteins showed an inverse correlation with cellular integrity as shown by light microscopy. We postulate that interstitial release of degradation products from triglycerides by lipase causes cellular disruption. Whereas phospholipase A2 and proteases do not seem to be very harmful in the early phases of cellular damage, lipase may play a major role in acute necrotizing pancreatitis.
 ...
PMID:Role of pancreatic enzymes and their substrates in autodigestion of the pancreas. In vitro studies with isolated rat pancreatic acini. 291 45

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.
 ...
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

Porcine pancreatic phospholipase A2 (PLA2) was immobilized to Sepharose 4B and porcine serum was passed through this affinity column. Bound substances were eluted by an EDTA-containing buffer and fractionated in a Sepharose 6B column. A single protein peak of the eluate from the latter column was found to inhibit PLA2 activity in a dose-dependent manner in an assay system using radioactive lecithin as a substrate and porcine pancreatic PLA2 as the enzyme source. The serum fraction containing the PLA2 inhibitory protein(s) (PIP) appeared inhomogeneous on SDS-polyacrylamide gel electrophoresis with two major bands close to each other, corresponding to a molecular weight of approximately 60,000. It was concluded that PIP might act as a protective principle against autodigestion in acute pancreatitis and other inflammatory diseases as well as playing a regulatory role in prostaglandin metabolism.
 ...
PMID:Presence of a phospholipase A2 inhibitor in porcine serum. 652 Jan 25

Acute pancreatitis (AP) is a common disease associated with an improper activation of pancreatic zymogens leading to autodigestion of the gland and if excessive--to multiple organ dysfunction. Acute necrotizing pancreatitis manifested by 20% of patients with acute pancreatitis is a life threatening disorder requiring subsequent management in intensive care unit. Unfortunately, none of biochemical tests presently used for laboratory assessment of acute pancreatitis at the early stage of the disease is able to estimate accurately: diagnosis, etiology and severity. At present, diagnosis of acute pancreatitis is based on evaluation of serum amylase and lipase activity due to easy availability and simplicity of these enzymatic tests. Low specificity of the mentioned enzymes resulted in studies concerning pancreatic isoamylase, elastase-1, chymotrypsine, procarboxy-peptidase B, trypsinogen-2 and immunoreactive trypsinogen usefulness in the laboratory diagnosis of AP. The prediction of severity in acute pancreatitis using multifactorial scoring systems is cumbersome especially due to their complexity. On the other hand the biochemical method of choice, estimation of serum C reactive protein, is useless in the early phase of disease. Unfortunately, the computed tomography--the most accurate method in severity assessing--is not always available. Recent studies have brought some progress in severity predicting, such as phospholipase A2, cellular immunity markers, cytokines, activation peptides of trypsinogen and carboxypeptidase B, procalcitonine, pancreatitis associated protein and serum amyloid A. All these newly introduced biochemical methods allow to look optimistically into the future of laboratory diagnostics of the acute pancreatitis believing that the problem of diagnosing and predicting the AP severity will be solved.
 ...
PMID:[Biochemical diagnostics in acute pancreatitis recognition and outcome predicition]. 1585 Mar 41