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Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The biochemical characterization of experimental acute pancreatitis was performed by determination of the secretory enzymes lipase and alpha-amylase, of the cytoplasmic ALAT (alanine aminotransferase), of total protein and calcium concentration in serum of rats. The moderate and protracted course of the pathological process in the small animal model presented allowed to study the initial phase from 1-24 h. In the first 4-8 h most massive enzyme release into the intravasal space was observed. The level of enzyme activities was correlating with the severity of assault. One noxa alone (ischemia or juice edema) resulted in a moderate enzyme release (lipase : 2-2.5 fold of control). The action of both noxae caused a drastical increase in enzyme activities in the initial phase lipase : 8-20 fold, ALAT: 7 fold, alpha-Amylase: 2.5 fold). 24 h postoperatively the serum enzyme activities were at distinct pathological level. At this time acute pancreatitis provoked already a decreased serum protein content. A hypocalcemia was not observed.
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PMID:Contribution of pancreatic edema and short-term ischemia to experimental acute pancreatitis in the rat. II. Behaviour of serum parameters. 349 93

Acute pancreatitis was produced in rats by a combination of dyschylic edema and short-term ischemia of the pancreas. The incidence of acute pancreatitis, reflected by peri- and extra-pancreatic fat necrosis, was found to be dependent on the duration of ischemia. Under most conditions there were no significant differences in enzyme activities between the animals with macroscopic signs and those without these. The time course of alpha-amylase and lipase release was investigated within 24 hours postoperatively. Additionally the quantitative correlation was estimated of the enzyme activities released from the pancreatic tissue and the activities determined in rat serum. The data show that the serum enzymes represent only a small and variable portion of the total amount of enzymes effused from the pancreas.
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PMID:Influence of pancreatic edema and short-term ischemia of rat pancreas on lipase- and alpha-amylase-activities in the serum and in the pancreas. 349 5

Three different levels of global forebrain ischemia were induced in rats and their plasma levels of Thromboxane B2 (TXB2) and 6 Keto PGF1 alpha were determined to investigate the relation between severity of ischemia and eicosanoid production. Ischemia stimulates the activity of cellular lipase whose actions cause deacylation of brain phospholipids and release of free fatty acids. Arachidonic acid (A.A.) is one of the predominant fatty acids which is liberated in brain after ischemia. A.A. is the primary substrate for the synthesis of prostaglandins (PGs), Thromboxane A2 (TXA2) and Prostacyclin (PGI2), which play an important role in regulation of platelet aggregation and vasotonus. Thromboxane is a potent platelet aggregator and vasoconstrictor. On the other hand, PGI2 has the opposite nature. Therefore it can be considered that PGs and moreover, the balance of TXA2 and PGI2 may have an intimate relation to the development of cerebral ischemia. Three different levels of ischemia were produced by bilateral carotid artery ligation (BLCL) using three kinds of rats with different blood pressure ranges, namely, SHRSP (Stroke-prone spontaneously hypertensive rats), SHRSR (Stroke-resistant spontaneously hypertensive rats) and WKY (Wistar kyoto rats). It is known that higher pressure groups suffer severe ischemia by BLCL procedure. Hypertensive rats (SHRSP, SHRSR) were originally produced from WKY. The experimental animals used were about 300 gr and 16 weeks old male rats. The plasma and brain TXB2 and 6 Keto-PGF1 alpha, stable metabolites of TXA2 and PGI2 were measured by radioimmunoassay. The chronological changes of brain and plasma PGs levels after ischemia using SHRSR were also investigated.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Effect of bilateral common carotid artery ligation on prostaglandin levels (TXA2, PGI2) in spontaneously hypertensive rats (SHRSP, SHRSR) and normotensive rats (WKY)]. 352 27

For investigations of cell injury during pathogenesis of acute pancreatitis antisera to pancreatic acinar cells were used as experimental tool. Within one hour after intraductal injection of antiserum a strong pancreatic edema was developed. Within 24 h this edema receded to a large extent but at this time there were inflammatory cells scattered in the intra- and periductal region. As a sequel of application of antiserum pancreatic enzymes were released. At 24 h after this application serum activities of alpha-amylase and lipase were significantly increased in comparison to the control and reached that level which was found in a model of acute pancreatitis provoked by pancreatic edema plus short-term ischemia.
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PMID:Influence of antisera to pancreatic acinar cells on rat pancreas in situ. 355 41

It has been well recognized that acyl groups of phospholipids play an important role for structure and function of biomembrane. The turnover of these acyl groups in normal brain biomembrane is also well known. Some types of enzymic system related to this turnover has been investigated. Phospholipase A, PI-specific phospholipase C, lipase, lysophospholipase and acylCoA: lysophospholipid acyltransferase belong to these enzymic systems. In this report, the sequential changes of phospholipase A, PI-specific phospholipase C, lipase, lysophospholipase and acylCoA: lysophospholipid acyltransferase activities in ischemic rat brain were examined. The purpose of this study was to examine the enzymic changes of deacylation-reacylation cycle of biomembrane phospholipid in ischemic brain. Ischemic brain were produced by decapitation and activities of 5 enzymes were assayed in microsomal fraction. The activities of phospholipase A, PI-specific phospholipase C, lipase showed high value during early stage of ischemia for 15 or 30 min and then decreased gradually. Lysophospholipase activity was not changed for 120 min. On the other hand, acylCoA: lysophospholipid acyltransferase activity showed gradual decrease from the beginning of ischemia. There are some reports that in early ischemic stage, the concent of free fatty acids increase, while that of phospholipid decrease. The present results may suggest that the changes of free fatty acid and phospholipid in ischemic brain are related to these enzymic system.
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PMID:[The activities of phospholipase A, PI-specific phospholipase C, lipase, lysophospholipase and acylCoA: lysophospholipid acyltransferase in ischemic brain microsomal fraction]. 402 86

The synthesis of phosphatidylcholine is catalyzed by cholinephosphotransferase (EC 2.7.8.2) which is known to be reversible in liver. The reversibility of cholinephosphotransferase in rat brain in demonstrated in this paper. Labeled microsomes were prepared from young rats which had been given an intracerebral injection of labeled choline or oleate 2 h before killing. During incubation of choline-labeled microsomes with CMP, label was lost from ;choline glycerophospholipids and labeled CDPcholine was produced. The Km for CMP was 0.35 mM and V was 3.3 nmol/min per mg protein. Neither AMP nor UMP could substitute for CMP. Oleate-labeled microsomes were pretreated with e mM diisopropylfluorophosphate (lipase inhibitor). During incubation with CMP, label was lost from choline, and ethanolamine glycerophospholipid and labeled diacylglycerols were produced. When the lipase was not inhibited, labeled oleate was produced. We propose that a principal pathway for degradation of phosphatidylcholine, particularly during brain ischemia, is by reversal of cholinephosphotransferase, followed by hydrolysis of diacylglycerols by the lipase.
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PMID:The reverse reaction of cholinephosphotransferase in rat brain microsomes. A new pathway for degradation of phosphatidylcholine. 626 65

The influence of a short-term ischemia of the pancreas for the pathogenesis of a hemorrhagic necrotising pancreatitis was investigated in 28 mongrel dogs. Ischemia of the pancreas in 20 minute intervals repeated three times did not leave any macroscopic, histologic or electron microscopic changes and no alterations of the level of the alpha-amylase, the lipase, and the glucose in the serum. An ischemia of 20 minutes' duration by starvation of the celiac artery and the superior mesenteric artery produces a hemorrhagic necrotising pancreatitis under the precondition of a following pancreatic edema by ligature of the pancreatic duct and secretomotoring with secretin and pancreozymin. The necrosis starts histologically in the perilobular adipose and affects the parenchyma later. Whether the lipase is the starting enzyme for the acute pancreatitis or only conditions the early adipose necrosis should be discussed after these findings. Already a fugitive pancreatic edema produces a hemorrhagic necrotising pancreatitis after previous ischemic damage.
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PMID:[Animal experiment studies on the role of ischemia in the pathogenesis of acute pancreatitis]. 633 88

The effects of several pancreatic enzymes on living tissue incapable of autodigestion were studied to analyse elements of the "pluralistic events of acute hemorrhagic pancreatitis" (Becker 1981). Phospholipase A2 induces (via toxic lysolecithin) cytotoxic necrosis in the testis; elastase (via destruction of vessels and local ischemia) causes hypoxic necrosis. Injection of lipase does not result in necrosis.
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PMID:Investigations into various pancreatic enzymes. 692 26

In an examination of the effect of ischemia and reperfusion on the generation of active oxygen species during pancreatic cell damage, a short-term ischemia and reperfusion model was prepared by the occlusion and reperfusion of both the anterior mesenteric artery and the celiac artery in rats. Following 60 minutes of occlusion plus 7 hours of reperfusion of the anterior mesenteric artery and the celiac artery, the serum concentrations of amylase and lipase rose significantly to 7 and 6 times the respective control values. After 30 minutes of occlusion plus 7 hours of reperfusion, or after 7 hours of occlusion without reperfusion, amylase and lipase levels were not changed significantly. The continuous intravenous infusion of superoxide dismutase (3600 U/kg/hour) in rats receiving 60 minutes of occlusion plus 7 hours of reperfusion suppressed the rise in serum amylase and lipase values to 25 percent of the values in the non-injected group. These results suggest that the active oxygen species which are generated by the short-term ischemia and reperfusion method injure the endothelium and cause hyperamylasemia and hyperlipasemia. Inhibition of the rise in serum amylase and lipase concentrations by pretreatment with a scavenger of active oxygen, superoxide dismutase, suggests that the active oxygen species are involved in the pathogenesis of acute pancreatitis.
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PMID:Effect of postischemic reperfusion on the pancreas. 750 64

The protective effects of a neutrophil elastase inhibitor (ONO-5046) on reperfusion injury following pancreaticoduodenal transplantation in rats were studied by measuring serum concentrations of cytokine-induced neutrophil chemoattractant (CINC). Male Wistar rats were transplanted with syngeneic pancreaticoduodenal grafts. ONO-5046 was injected intravenously 5 min before vascular clamping and immediately after reperfusion at a dose of 10 mg/kg. No significant differences were observed in the peak serum concentrations of amylase between the groups treated with and treated without ONO-5046. The serum lipase concentrations in the untreated animals increased and peaked 3 hr after reperfusion. ONO-5046 significantly decreased the peak serum lipase concentration. The serum CINC concentrations, which were determined by enzyme-linked immunosorbent assay, increased and peaked 3 hr after reperfusion, decreasing gradually thereafter. However, pretreatment with ONO-5046 significantly inhibited the rise in serum CINC concentrations after reperfusion. Expression of CICN transcripts in the pancrease grafts was evaluated by Northern blot analysis and peaked 3 hr after reperfusion in untreated animals. Pretreatment with ONO-5046 also significantly inhibited the expression of CINC mRNA transcripts in the graft. ONO-5046 significantly decreased the number of neutrophils accumulated in the pancreas graft 24 hr after transplantation. In vitro CINC production by peritoneal macrophages was increased by neutrophil elastase in dose-dependent fashion. However, ONO-5046 decreased CINC production by peritoneal macrophages in response to neutrophil elastase. These results suggest that ONO-5046 prevents early neutrophil accumulation in the pancreas following ischemia/reperfusion of pancreaticoduodenal transplantation.
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PMID:Neutrophil elastase inhibitor (ONO-5046) decreases cytokine-induced neutrophil chemoattractant after reperfusion of pancreaticoduodenal transplantation in rats. 862 93


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