Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0030305 (pancreatitis)
 16,014 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The aim of the present study was to determine the role of endogenous nitric oxide (NO) in pancreatic secretion in vivo and amylase release from pancreatic acini in vitro and in caerulein-induced acute pancreatitis in rats. Blockade of NO synthase by NG-nitro-L-arginine (L-NNA) (2.5 mg/kg i.v.) significantly reduced basal pancreatic protein secretion and that induced by the infusion of CCK (0.5 micrograms/kg-h), feeding, and the diversion of pancreatic juice in rats with pancreatic fistula. This inhibitory effect was partially reversed when L-arginine (50 mg/kg-h i.v.) was added to L-NNA. L-Arginine alone (50 mg/kg i.v.) did not affect basal or caerulein-induced pancreatic secretion. L-NNA, L-arginine, or their combination added in various concentrations to the incubation medium of dispersed acini failed to affect basal or secretagogue (caerulein or urecholine) stimulated amylase release. Infusion of caerulein (5 micrograms/kg-h) for 5 h produced histological changes of acute edematous pancreatitis accompanied by a marked increase in pancreatic protein content and about 50% reduction in tissue blood flow. L-NNA alone also reduced the pancreatic blood flow and caused a significant increase in pancreatic weight and protein content. L-NNA significantly potentiated the inflammatory changes in the pancreas caused by caerulein. Addition of L-arginine enhanced the pancreatic blood flow and ameliorated the pancreatitis induced by caerulein alone or that combined with L-NNA. We conclude that NO is involved in the stimulation of pancreatic secretion in vivo and exhibits a beneficial effect on pancreatitis, probably by improving the pancreatic blood flow.
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PMID:Nitric oxide in pancreatic secretion and hormone-induced pancreatitis in rats. 751 91

The objective of this study was to determine whether the observed vascular collapse and other pathologic features of severe pancreatitis may be related to the induction of nitric oxide synthase (NOS). The rat model of pancreatitis reported by Schmidt et al. was employed. Rats in the experimental groups received pretreatment with known NOS inhibitors, N-Monomethylarginine (NMMA) or Aminoguanidine (AG). Controls included sham-operated rats without pancreatic insult and a diseased control group which received pretreatment with normal saline (NS). Arterial blood pressure was continuously recorded with a femoral arterial catheter connected to a transducer and monitor. Fluid resuscitation for hypotension followed a strict protocol with the administration of 5.0 cc NS for sustained decreases in systolic blood pressure (SBP) below 90 mm Hg at 5-minute intervals. Laboratory parameters and histopathology confirmed the induction of pancreatitis, with 6 to 15-fold increases in serum amylase levels and an average of approximately 20% decrease in serum ionized Ca++ levels. Immunohistochemical studies of the pancreas revealed that pancreatic insult resulted in the induction of NOS. Rats in the saline control group (n = 5) became hypotensive (SBP less than 90 mm Hg) between 3 and 4 hours post pancreatic insult and required an average of 110.0 cc (3-4 x blood volume) of NS fluid resuscitation. Rats which were not resuscitated (n = 5) did not survive.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:First place winner of the Conrad Jobst Award in the gold medal paper competition. Nitric oxide synthase inhibitors N-monomethylarginine and aminoguanidine prevent the progressive and severe hypotension associated with a rat model of pancreatitis. 753 Apr 15

Nitric oxide (NO) has been implicated to regulate pancreatic circulation, promote capillary integrity, and inhibit leukocyte adhesion. We investigated the role of NO in the development of pancreatitis. Nitro-L-arginine, an inhibitor of NO synthase, in total dose of 35 mg/kg body wt was infused in the rats with edematous pancreatitis induced by two intraperitoneal injections of cerulein (20 micrograms/kg). L-Arginine (125 or 250 mg/kg), a NO donor was intravenously administered twice in the rats with hemorrhagic pancreatitis induced by water-immersion stress plus two intraperitoneal injections of cerulein (40 micrograms/kg). The degree of pancreas edema, serum amylase levels, and histologic alterations were investigated. Nitro-L-arginine exacerbated cerulein-induced pancreatitis and caused a decrease in pancreatic blood flow. L-Arginine ameliorated the severity of hemorrhagic pancreatitis dose dependently and improved the pancreatic blood flow. These findings suggest that NO could confer protection against the development of hemorrhagic pancreatitis, probably through improvement of the pancreatic microcirculation.
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PMID:Protective effect of nitric oxide on development of acute pancreatitis in rats. 758 83

The effect of bradykinin on nitric oxide generation and eicosanoid production in the early stage of an experimental model of acute necrotizing pancreatitis induced by sodium taurocholate has been evaluated. We have compared the effect of administering a long-acting bradykinin antagonist, HOE 140, and an inhibitor of nitric oxide synthase, NG-nitro-L-arginine methyl esther L-NAME) on pancreatic prostanoid synthesis. Plasma lipase levels were increased after acute pancreatitis induction, and reduced after HOE 140 or L-NAME administration. Nitric oxide production and thromboxane B2 levels were increased after pancreatitis induction and the increases were reduced by L-NAME or HOE 140 administration. In contrast, increased prostacyclin production, reflected as 6-keto-PGF1 alpha levels, was not modified by L-NAME or HOE 140. Bradykinin seems to be involved in nitric oxide and thromboxane synthesis during the initial phases of acute necrohemorrhagic pancreatitis.
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PMID:A bradykinin antagonist inhibited nitric oxide generation and thromboxane biosynthesis in acute pancreatitis. 765 83

The role of nitric oxide in eicosanoid and oxygen-free radical production in the early stages of sodium taurocholate-induced acute necrotizing pancreatitis has been studied. Male Wistar rats were divided into three groups: group I: control group, a volume of 0.1 ml/100 g body wt saline solution was injected at low pressure in the pancreatic duct; group II: acute pancreatitis was induced by administration of 3.5% sodium taurocholate; and group III: intravenous administration of NG-nitro-L-arginine methyl esther (a nitric oxide synthase inhibitor) 5 min before induction of acute pancreatitis as stated for group II. At 5 and 60 min after induction of pancreatitis, blood and pancreas tissue samples were taken for assays. Increases in 6-keto PGF1 alpha, TXB2, PGE2, PGF2 alpha, and 12-HETE were observed in the pancreatic tissue. Lipoperoxidation was also enhanced and remained unaltered after nitric oxide inhibition. The fact that nitric oxide synthase inhibition could only reverse the increases in 6-keto PGF1 alpha and TXB2 levels indicates that in acute pancreatitis endothelial and platelet eicosanoid generation is mediated through an nitric oxide-dependent mechanism. In contrast, nitric oxide appears to be not related with oxygen free radical damage associated with acute pancreatitis.
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PMID:Prostanoid generation in early stages of acute pancreatitis: a role for nitric oxide. 784 92

This study was designed to investigate the role of nitric oxide (NO) in the formation of pancreatic edema in caerulein-induced pancreatitis in rats. Pancreatitis was produced by two intraperitoneal injections of caerulein, and plasma amylase concentration, pancreatic edema index (pancreatic wet weight/body weight), and Evans blue extravasation (as a measure of vascular permeability) were evaluated 5 h after the first injection. Four doses (1, 2.5, 5, and 10 mg/kg) of NG-nitro-L-arginine (L-NNA), an NO synthase inhibitor, were subcutaneously administered at -0.5, 0.5, 1.5, 2.5, and 3.5 h after the first injection of caerulein. L-NNA significantly lowered the edema index, the wet/dry weight ratio of the pancreas, and Evans blue extravasation in the rats with pancreatitis. The maximal effect was obtained by L-NNA at a dose of 2.5 mg/kg; this inhibited the increase in pancreatic edema formation from the control value by 60%-70%. Intraperitoneal injections (20 mg/kg, five times) of L-arginine, a substrate for NO production, partly reversed the L-NNA-induced inhibition of pancreatic edema formation, but D-arginine, an enantiomer of L-arginine, did not show any effect. Plasma amylase concentrations were not significantly affected by any dose of L-NNA, nor were they affected by L- or D-arginine. These findings strongly suggest that endogenous NO plays an important role in the formation of pancreatic edema in caerulein-induced pancreatitis in rats, probably by increasing vascular permeability and protein extravasation.
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PMID:Nitric oxide modulates pancreatic edema formation in rat caerulein-induced pancreatitis. 857 37

Nitric oxide (NO) has been shown to play a significant role in inflammation. To clarify the role of NO in acute pancreatitis, we investigated the serum concentrations of NO chi (NO2- plus NO3-) and tumor necrosis factor-alpha (TNF-alpha) and the grade of pancreatitis in cerulein-induced pancreatitis in mice pretreated with lipopolysaccharide (LPS) or not. LPS pretreatment aggravated the cerulein pancreatitis in association with a transient increase in serum TNF-alpha, which was followed by a gradual elevation of serum NO chi. This elevation of serum NO chi concentration was inhibited by the NO synthase inhibitor NG-nitro-L-arginine (L-NNA). In addition, the activity of NADPH-diaphorase (NADPH-d), a marker for NO synthase, appeared in the peritoneal macrophages of LPS-pretreated mice after the induction of pancreatitis. No elevation of serum NO chi or appearance of NADPH-d activity in peritoneal cells was found in mice without LPS pretreatment. Administration of L-NNA enhanced the elevation of pancreatitis-induced serum amylase in mice untreated with LPS, while L-NNA inhibited the elevation in LPS-pretreated mice. The effects of L-NNA were reversed by the administration of L-arginine but were not affected by D-arginine. These results suggested that (a) inflammatory cells may not be fully activated to produce excessive NO in uncomplicated edematous pancreatitis, and (b) edematous pancreatitis may be aggravated by excessively produced NO if bacterial infection is complicated and inflammatory cells are activated to express inducible NO synthase.
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PMID:The role of nitric oxide in mouse cerulein-induced pancreatitis with and without lipopolysaccharide pretreatment. 892 22

The aim of the study was to investigate the potential role of nitric oxide (NO) on the microcirculation in experimental acute pancreatitis in rats. Twenty-five rats were divided into the following groups: group A (5 rats) = control; group B (5 rats) = acute pancreatitis induced by retrograde taurocholate infusion into the pancreatobiliary duct without treatment; group C (5 rats) = acute pancreatitis treated with the NO donor L-arginine; group D (5 rats) = acute pancreatitis treated with the NO synthase inhibitor N-nitro-L-arginine (L-NNA); group E (5 rats) = without pancreatitis receiving L-NNA. The animals were observed throughout 4 h. The microcirculatory values of the pancreas, liver, colon, stomach and kidney were measured by means of laser Doppler flowmetry. Three animals of group D died after the third hour of the experiment. In rats with pancreatitis, a rapid decrease in microcirculatory values was observed. The most pronounced drop in capillary blood flow within all the organs was observed in rats treated with the NO synthase inhibitor L-NNA, L-arginine administration in rats with acute pancreatitis slightly improved the microcirculatory values, although the improvement was significant in colon perfusion only. We conclude that NO may have a beneficial influence on the capillary organ perfusion in acute pancreatitis. The administration of an NO synthase inhibitor seems to have a detrimental effect on acute pancreatitis.
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PMID:Does nitric oxide protect from microcirculatory disturbances in experimental acute pancreatitis in rats? 895 19

Hypotension is a serious problem in septic patients. We investigated regional perfusion in several organs during treatment of hyperdynamic sepsis in sheep. Sepsis was induced and maintained for the entire experiment with a continuous infusion of live Pseudomonas aeruginosa. Treatment with either norepinephrine or the nitric oxide synthase inhibitor L omega-mono-methyl-arginine (L-NMMA) was begun after 24 h of sepsis and continued for 24 h. The norepinephrine dosage was adjusted to achieve the same increase in mean arterial pressure as that obtained by a fixed dose of L-NMMA (7 mg/kg/h). Blood flows were analyzed by the microsphere technique. Both compounds restored blood pressure effectively, but only L-NMMA caused a significant increase in systemic vascular resistance, concomitant with a significant fall in cardiac output. Sepsis caused an increase in myocardial blood flow and a redistribution of blood flow away from the pancreas and the stomach. Renal blood flow was not significantly elevated. During treatment with either compound, renal blood flow remained unchanged, despite a fall in cardiac output in the L-NMMA group. Unchanged renal blood flow combined with the restoration of arterial blood pressure caused a significant increase in urine output. Both L-NMMA and norepinephrine caused a redistribution of blood flow to the colon. Pancreatic blood flow was further reduced by L-NMMA but the oxygen extraction improved simultaneously, so that oxygen availability in the pancreas might have been unchanged. Because ischemic pancreatitis in sepsis is likely to trigger multiorgan failure, further investigations in that area are desirable.
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PMID:Nitric oxide synthase inhibition versus norepinephrine in ovine sepsis: effects on regional blood flow. 915 93

Local microcirculatory dysfunction within the pancreatic gland might be an important factor in the conversion of oedematous to necrotizing pancreatitis. Therapeutic agents, improving the pancreatic blood flow, might be valuable in acute pancreatitis treatment. An influence of nitric oxide, heparin and procaine treatment on microcirculatory values in acute pancreatitis (AP) in rats was investigated. Acute pancreatitis was induced by i.p. injection of cerulein in four doses of 15 microg kg-1 each at 1-h intervals. The rats with pancreatitis were divided into five groups, 12 animals each. One group remained without treatment, four groups were treated i.p. either with NO synthase inhibitor L-NNA (2x25 mg kg-1 or heparin 2x2.5 mg kg-1 or L-arginine 2x100 mg kg-1 or procaine 2x25 mg kg-1. Five control groups, ten animals each, received saline, L-NNA, heparin, L-arginine or procaine only. Five hours after the first ceruleine injection microcirculatory values within the pancreas were measured by means of laser Doppler flowmetry. Acute pancreatitis caused a significant drop of microcirculatory value to 37% of the basal value. The L-NNA administration resulted in a further insignificant reduction of the pancreatic blood flow to 34%. An improvement of microcirculation was observed in rats with pancreatitis receiving heparin (76%) and L-arginine (72%). Procaine had no effect on microcirculatory disturbances within the pancreas in rats with pancreatitis. Cn-induced acute pancreatitis (AP) causes microcirculatory deterioration within the pancreas. Heparin and nitric oxide donor, L-arginine, might be considered as therapeutic agents, improving the diminished pancreatic tissue perfusion observed in acute pancreatitis. Procaine does not improve the pancreatic blood flow in acute pancreatitis.
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PMID:Microcirculatory disturbances of the pancreas in cerulein-induced acute pancreatitis in rats with reference to L-arginine, heparin, and procaine treatment. 934 40


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