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Background: Nontoxic heat shock protein (HSP) inducer compounds open up promising therapeutic possibilities by activating one of the natural and highly conserved defense mechanisms of the organism. Aims: In the present experiments, we examined the effects of a HSP coinducer drug-candidate, BRX-220, on the cholecystokinin-octapeptide (CCK)-induced acute pancreatitis in rats. Methods: Male Wistar rats weighing 240 to 270 g were divided into two groups. In group B, 20 mg/kg BRX-220 was administered orally, followed by 75 μg/kg CCK subcutaneously three times, after 1, 3, and 5 h. This whole procedure was repeated for 5 d. The aminals in group B received physiological saline orally instead of BRX-220, but otherwise the protocol was the same as in group B. The rats were exsanguinated through the abdominal aorta 12 h after the last administration of CCK. We determined the serum amylase activity, the plasma trypsinogen activation peptide concentration, the pancreatic weight/body weight ratio, the DNA and total protein contents of the pancreas, the levels of pancreatic HSP60 and HSP72, the activities of pancreatic amylase, lipase, trypsinogen, and free radical scavenger enzymes (superoxide dismutase, catalase, and glutathione peroxidase), the degree of lipid peroxidation, protein oxidation, and the reduced glutathione level. Histopathological investigation of the pancreas was also performed in all cases. Results: Repeated CCK treatment resulted in the typical laboratory and morphological changes of experimentally induced pancreatitis. The pancreatic levels of HSP60 and HSP72 were significantly increased in the animals treated with BRX-220. In group B, the pancreatic total protein content and the amylase and trypsinogen activities were significantly higher vs. group B. The plasma trypsinogen activation peptide concentration, and the pancreatic lipid peroxidation, protein oxidation, and the activity of Cu/Zn-superoxide dismutase were significantly decreased in group B vs. group B, whereas the glutathione peroxidase activity was increased. The morphological damage in group B was significantly lower than that in group B. Conclusion: The HSP coinducer BRX-220, administered for 5 d, has a protective effect against CCK-induced acute pancreatitis.  相似文献   

3.
This study was aimed at an assessment of the role of oxygen-derived free radicals, cytokines and endogenous cholecystokinin (CCK) in the pathogenesis of L-arginine (Arg)-induced acute pancreatitis in rat. We measured the levels of malonyl dialdehyde (MDA), glutathione peroxidase (GPx), catalase and superoxide dismutase (Mn- and Cu, Zn-SOD) in pancreatic tissue, the serum levels of tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6) and CCK, and evaluated the protective effect of the xanthine oxidase inhibitor allopurinol and a novel CCK receptor antagonist KSG-504. Acute pancreatitis was induced in male Wistar rats by injecting 2x 250 mg/100 g body weight of Arg intraperitoneally in an 1-h interval, as a 20% solution in 0.15 M NaCl. Control rats received the same quantity of glycine. 200 mg x kg(-1) allopurinol 30 min before the first Arg treatment or 50 mg x kg(-1) KSG-504 30 min before and 6, 18 and 36 h after the first Arg injection was administered subcutaneously. Rats were killed at 6, 12, 24 and 48 h following Arg administration, and acute pancreatitis was confirmed by a serum amylase level elevation and typical inflammatory features observed microscopically. The serum level of amylase reached the peak level at 24 h after the Arg injection (30,800 +/- 3,813 versus 6,382 +/- 184 U x L(-1) in the control) and normalized at 48 h. The tissue concentration of MDA was significantly elevated at 24 h, and reached the peak value at 48 h (5.00 +/- 1.75 versus 0.28 +/- 0.05 nM x mg(-1) protein in the control). The catalase and Mn-SOD activities were significantly decreased throughout the study, while the GPx activity was significantly reduced at 6 and 12 h, and the Cu, Zn-SOD activity was significantly lower at 12 h after the Arg injection as compared with the controls. Both the TNF-alpha and the IL-6 levels were already elevated significantly at 12 h and peak at 24 h versus the controls (19.1 +/- 7.9 U x mL(-1) and 57.6 +/- 11.2 pg x mL(-1) versus 3.1 +/- 0.8 U x mL(-1) and 15.2 +/- 3.1 pg x mL(-1), respectively). No significant changes in plasma CCK levels were observed. Allopurinol treatment markedly reduced the serum amylase elevation (12.631 +/- 2.257 U x L(-1) at 24 h), prevented the increase in tissue MDA concentration (0.55 +/- 0.09 nM x mg(-1) protein at 48 h) and significantly ameliorated the pancreatic edema, necrosis and inflammation at 48 h after Arg administration. KSG-504 administration did not exert any beneficial effect on the development of histopathological changes neither modified the serum amylase or cytokine levels. Oxygen-derived free radicals and cytokines are involved, while endogenous CCK does not seem to play a role in the pathogenesis of Arg-induced acute pancreatitis.  相似文献   

4.
Heat shock proteins (HSPs), induced by a variety of stresses, are known to protect against cellular injury. Recent studies have demonstrated that prior beta-adrenergic stimulation as well as thermal or culture stress induces HSP70 expression and protects against cerulein-induced pancreatitis. The goal of our current studies was to determine whether or not a non-thermal, chemical stressor like sodium arsenite also upregulates HSP70 expression in the pancreas and prevents secretagogue-induced trypsinogen and NF-kappaB activation. We examined the effects of sodium arsenite preadministration on the parameters of cerulein-induced pancreatitis in rats and then monitored the effects of preincubating pancreatic acini with sodium arsenite in vitro. Our results showed that sodium arsenite pretreatment induced HSP70 expression both in vitro and in vivo and significantly ameliorated the severity of cerulein-induced pancreatitis, as evidenced by the markedly reduced degree of hyperamylasemia, pancreatic edema, and acinar cell necrosis. Sodium arsenite pretreatment not only inhibited trypsinogen activation and the subcellular redistribution of cathepsin B, but also prevented NF-kappaB translocation to the nucleus by inhibiting the IkappaBalpha degradation both in vivo and in vitro. We also examined the effect of sodium arsenite pretreatment in a more severe model of pancreatitis induced by L-arginine and found a similarly protective effect. Based on our observations we conclude that, like thermal stress, chemical stressors such as sodium arsenite also induce HSP70 expression in the pancreas and protect against acute pancreatitis. Thus, non-thermal pharmacologically induced stress can help prevent or treat pancreatitis.  相似文献   

5.
The proteasome inhibitor MG132 protects against acute pancreatitis   总被引:6,自引:0,他引:6  
The cell-permeant MG132 tripeptide (Z-Leu-Leu-Leu-aldehyde) is a peptide aldehyde proteasome inhibitor that also inhibits other proteases, including calpains and cathepsins. By blocking the proteasome, this tripeptide has been shown to induce the expression of cell-protective heat shock proteins (HSPs) in vitro. Effects of MG132 were studied in an in vivo model of acute pancreatitis. Pancreatitis was induced in male Wistar rats by injecting 2 x 100 microug/kg cholecystokinin octapeptide intraperitoneally (ip) at an interval of 1 h. Pretreating the animals with 10 mg/kg MG132 ip before the induction of pancreatitis significantly inhibited IkappaB degradation and subsequent activation of nuclear factor-kappaB (NF-kappaB). MG132 also increased HSP72 expression. Induction of HSP72 and inhibition of NF-kappaB improved parameters of acute pancreatitis. Thus MG132 significantly decreased serum amylase, pancreatic weight/body weight ratio, pancreatic myeloperoxidase activity, proinflammatory cytokine concentrations, and the expression of pancreatitis-associated protein. Parameters of oxidative stress (GSH, MDA, SOD, etc.) were improved in both the serum and the pancreas. Histopathological examinations revealed that pancreatic specimens of animals pretreated with the peptide demonstrated milder edema, cellular damage, and inflammatory activity. Our findings show that simultaneous inhibition of calpains, cathepsins, and the proteasome with MG132 prevents the onset of acute pancreatitis.  相似文献   

6.
A variety of receptors on pancreatic acinar and duct cells regulate both pancreatic exocrine secretion and intracellular processes. These receptors are potential sites of action for therapeutic agents in the treatment of pancreatitis. Cholecystokinin (CCK) receptor antagonists, which may reduce the level of metabolic "stress" on acinar cells, have been shown to mitigate the severity of acute pancreatitis in a number of models. Not all studies have shown a benefit, however, and differences may exist between different structural classes of antagonists. Because increased pancreatic stimulation due to loss of feedback inhibition of CCK has been proposed to contribute to the pain of some patients with chronic pancreatitis, CCK receptor antagonists could also be of benefit in this setting. Somatostatin and its analogs diminish pancreatic secretion of water and electrolytes and have been effective in treating pancreatic fistulas and pseudocysts. These agents are also being evaluated for their ability to reduce pain in chronic pancreatitis (perhaps by reducing ductal pressure by diminishing secretory volume) and mitigating the severity of acute pancreatitis (possibly by reducing the metabolic load on acinar cells). Recently described secretin receptor antagonists may also have therapeutic value as a means of selectively inhibiting pancreatic secretion of water and electrolytes.  相似文献   

7.
The gastrointestinal hormone cholecystokinin (CCK) can induce acute pancreatitis in rodents through its action on acinar cells. Treatment with CCK, in combination with other agents, represents the most commonly used model to induce experimental chronic pancreatitis. Pancreatic stellate cells (PSC) are responsible for pancreatic fibrosis and therefore play a predominant role in the genesis of chronic pancreatitis. However, it is not known whether PSC express CCK receptors. Using real time PCR techniques, we demonstrate that CCK1 and CCK2 receptors are expressed on rat PSC. Interestingly both CCK and gastrin significantly induced type I collagen synthesis. Moreover, both inhibit proliferation. These effects are comparable with TGF-β-stimulated PSC. Furthermore, the natural agonists CCK and gastrin induce activation of pro-fibrogenic pathways Akt, ERK, and Src. Using specific CCK1 and CCK2 receptor (CCK2R) inhibitors, we found that Akt activation is mainly mediated by CCK2R. Akt activation by CCK and gastrin could be inhibited by the PI3K inhibitor wortmannin. Activation of ERK and the downstream target Elk-1 could be inhibited by the MEK inhibitor U0126. These data suggest that CCK and gastrin have direct activating effects on PSC, are able to induce collagen synthesis in these cells, and therefore appear to be important regulators of pancreatic fibrogenesis. Furthermore, similar to TGF-β, both CCK and gastrin inhibit proliferation in PSC.  相似文献   

8.
Although the pancreatic heat shock response has already been reported to confer protective effects during experimental pancreatitis, the mechanism of action remains unknown. We investigated the effects of hyperthermia in cerulein-induced pancreatitis. Heat shock protein 70 (HSP70) expression in rats was induced by a 20-min period of water immersion (42 degrees C). The severity of pancreatitis as well as the pancreatic expression of cytokines, nuclear factor-kappaB (NF-kappaB), and inhibitory factor kappaB-alpha (IkappaB-alpha) were evaluated in the presence and absence of hyperthermia. We found that hyperthermia resulted in time-dependent expression of HSP70 within the pancreas associated with a reduction in the severity of acute pancreatitis. Tumor necrosis factor-alpha and intercellular adhesion molecule-1 expression was significantly reduced in the presence of hyperthermia. Moreover, NF-kappaB activity was delayed in the presence of hyperthermia whereas IkappaB-alpha was stabilized in the cytoplasm. These results suggest that hyperthermia decreases the severity of cerulein-induced pancreatitis by decreasing cytokine expression in the pancreas through the modulation of NF-kappaB activity.  相似文献   

9.
Little is known about the changes in pancreatic enzyme storage in acute pancreatitis. We have performed flow cytometric studies of zymogen granules from rats with acute pancreatitis induced by hyperstimulation with caerulein. A comparison was made with rats treated with hydrocortisone (10 mg/kg/day) over 7 days before inducing pancreatitis in order to find out whether the amount of enzymes stored in the pancreas plays a key role in the development of pancreatitis. The potentially therapeutic effect of L-364,718 (0.1 mg/kg/day, for 7 days), a CCK receptor antagonist, was assayed in the rats with caerulein-induced pancreatitis which had previously received the hydrocortisone treatment. A significant increase in the intragranular enzyme content was observed 5 h after hyperstimulation with caerulein. The highest values were reached in the rats previously treated with hydrocortisone. The greatest pancreatic enzyme load was parallel to the highest values in plasma amylase, edema and haematocrit observed. Acute pancreatitis was reversed seven days later. At this stage smaller granules appeared in the pancreas whose enzyme content was similar to that of controls when no treatment was applied after pancreatitis. In contrast, L-364,718 administration prevented the favourable evolution of pancreatitis since the antagonism exerted on CCK receptors induced a blockade of secretion of the large amounts of enzymes stored in the pancreas. Moreover, the enzyme content in zymogen granules was below normal values since the stimulatory CCK action on enzyme synthesis can be inhibited by L-364,718. Our results suggest that the efficiency of CCK antagonists, as potential therapy, would also depend on the load of enzymes in the pancreas when acute pancreatitis is produced.  相似文献   

10.
Hot-water immersion (HWI) is a type of thermal therapy for treating various diseases. In our study, the physiological responses to occasional and regular HWI have been explored. The rats were divided into a control group, occasional group (1D), and regular group (7D). The 1D and 7D groups received 42 °C during 15 mins HWI for 1 and 7 days, respectively. The blood samples were collected for proinflammatory cytokines examinations, the heart, liver and kidney were excised for subsequent IHC analysis to measure the level of heat shock protein 70 (HSP70). The results revealed that the body temperature increased significantly during HWI on Day 3 and significantly declined on Days 6 and 7. For the 7D group, body weight, heart rate, hematocrit, platelet, osmolarity, and lactate level were lower than those in the 1D group. Furthermore, the levels of granulocyte counts, tumor necrosis factor-α, and interleukin-6 were lower in the 7D group than in the 1D group. The induction of HSP70 in the 1D group was higher than in the other groups. Physiological responses to occasional HWI are disadvantageous because of heat stress. However, adaptation to heat from regular HWI resulted in decreased proinflammatory responses and physical heat stress.  相似文献   

11.

Purpose

We evaluated the effect of different water immersion (WI) temperatures on post-exercise cardiac parasympathetic reactivation.

Methods

Eight young, physically active men participated in four experimental conditions composed of resting (REST), exercise session (resistance and endurance exercises), post-exercise recovery strategies, including 15 min of WI at 15°C (CWI), 28°C (TWI), 38°C (HWI) or control (CTRL, seated at room temperature), followed by passive resting. The following indices were assessed before and during WI, 30 min post-WI and 4 hours post-exercise: mean R-R (mR-R), the natural logarithm (ln) of the square root of the mean of the sum of the squares of differences between adjacent normal R–R (ln rMSSD) and the ln of instantaneous beat-to-beat variability (ln SD1).

Results

The results showed that during WI mRR was reduced for CTRL, TWI and HWI versus REST, and ln rMSSD and ln SD1 were reduced for TWI and HWI versus REST. During post-WI, mRR, ln rMSSD and ln SD1 were reduced for HWI versus REST, and mRR values for CWI were higher versus CTRL. Four hours post exercise, mRR was reduced for HWI versus REST, although no difference was observed among conditions.

Conclusions

We conclude that CWI accelerates, while HWI blunts post-exercise parasympathetic reactivation, but these recovery strategies are short-lasting and not evident 4 hours after the exercise session.  相似文献   

12.
The aim of the present work was to investigate the laboratory and morphologic alterations in the pancreas 6 months after pancreatitis induction with L-arginine (Arg) in normal and streptozotocin (STZ)-diabetic rats. The amylase content of the pancreas was significantly decreased in the Arg-treated groups vs. the control group. No significant changes were observed in the DNA, soluble protein and lipase contents of the pancreas. In the STZ-treated groups, the serum glucose level was significantly elevated, whereas the serum immunoreactive insulin (IRI) level was significantly decreased vs. the control group. In these treated groups, the amylase content of the pancreas was also significantly decreased, but that of trypsinogen was significantly elevated vs. the control group. Histologic sections revealed periductal fibroses, adipose tissue and tubular complexes in the Arg-treated rats, but centroacinar hyperplasia was not observed in these groups. No alterations were observed on histological examination in the diabetic rats vs. normal rats 6 months following pancreatitis induction. In conclusion, a major restitution of the pancreatic enzyme content, but moderate histologic alterations were detected 6 months following pancreatitis induction with Arg. The diabetic state appeared to shift the normal pancreatic enzyme content (decreased amylase and increased trypsinogen) in this long-term study, but not to modify the recovery of the exocrine pancreas 6 months following Arg-induced pancreatitis.  相似文献   

13.
《Free radical research》2013,47(11):934-940
Abstract

There is a convincing body of evidence that oxidative stress is involved in the pathogenesis of acute pancreatitis. The effects of different radical scavengers suggested that reactive oxygen metabolites are generated at very early stage of disease and contribute to amplify the pancreatic damage. Oxidative stress is also involved in the progression of the disease from a local damage to a systemic organ failure. However, therapeutic use of antioxidants failed to clearly show a clinical benefit in different trials. Therefore, although antioxidants alone seem to be not enough for the treatment of severe acute pancreatitis, future combined therapeutic strategies should include antioxidants in its composition.  相似文献   

14.
Recent studies have indicated that pre-induction of heat shock protein 70 (HSP70) expression in the pancreas protects against secretagogue-induced pancreatitis. In those studies, the HSP70 was mostly induced by unfeasible conditions. The aim of this current study was to investigate the effect of peritoneal lavage with hot 0.9 % saline (42 °C) on the pancreatic expression of HSP70 and its protective effect on cerulein-induced acute pancreatitis in rats. Male Wistar rats were peritoneally lavaged with 0.9 % saline at 42 °C for 30 min. HSP70 expression was evaluated by western blotting analysis. Prior peritoneal lavages with hot and warm saline were performed. Acute pancreatitis was induced by administration of intraperitoneal injection of cerulein (20 μg/kg) four times, and its severity was assessed by measuring serum amylase, tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and trypsinogen activation peptide (TAP) levels. Pancreatic sections were stained with hematoxylin and eosin for histological evaluation. Peritoneal lavage with hot 0.9 % saline increased intrapancreatic HSP70 expression and ameliorated the cerulein-induced pancreatitis in rats, judged by the significantly reduced serum amylase, TNF-α, and IL-6 concentrations; histopathological scores, and serum TAP levels. Peritoneal lavage with hot 0.9 % saline can induce HSP70 expression and prevent cerulein-induced acute pancreatitis in rats. The results suggest that HSP70 protects against cerulein-induced pancreatitis by preventing proinflammatory cytokine synthesis and trypsinogen activation during acute pancreatitis.  相似文献   

15.
In contrast to supramaximal CCK-8 or caerulein, acute or prolonged supraphysiological levels of endogenous CCK-58 do not cause pancreatitis. Compared with CCK-8, CCK-58 is a much stronger stimulant of pancreatic chloride and water secretion, equivalent to maximally effective secretin, but with a chloride-to-bicarbonate ratio characteristic of acinar fluid. Because supraphysiological endogenous CCK does not cause pancreatitis and because coadministration of secretin ameliorated caerulein- or CCK-8-induced pancreatitis, coincident with restoring pancreatic water secretion, we hypothesized that supramaximal CCK-58 would not induce pancreatitis. Conscious rats were infused intravenously with 2 or 4 nmol x kg(-1) x h(-1) of CCK-8 or synthetic rat CCK-58 for 6 h, and pancreases were examined for morphological and biochemical indexes of acute pancreatitis. A second group was treated as above while monitoring pancreatic protein and water secretion. CCK-8 at 2 nmol x kg(-1) x h(-1) caused severe edematous pancreatitis as evidenced by morphological and biochemical criteria. CCK-58 at this dose had minimal or no effect on these indexes. CCK-58 at 4 nmol x kg(-1) x h(-1) increased some indexes of pancreatic damage but less than either the 2 or 4 nmol x kg(-1) x h(-1) dose of CCK-8. Pancreatic water and protein secretion were nearly or completely abolished within 3 h of onset of CCK-8 infusion, whereas water and protein secretion were maintained near basal levels in CCK-58-treated rats. We hypothesize that supramaximal CCK-58 does not induce pancreatitis because it maintains pancreatic acinar chloride and water secretion, which are essential for exocytosis of activated zymogens. We conclude that CCK-58 may be a valuable tool for investigating events that trigger pancreatitis.  相似文献   

16.
17.
Mammalian cells exhibit increased sensitivity to hyperthermic temperatures of 38-43 degrees C after an acute high-temperature heat shock; this phenomenon is known as the stepdown heating (SDH) effect. We characterized the SDH effect on (1) the synthesis of major heat shock proteins, HSP110, 90, 72/70, 60 (35S-amino acids label), (2) on heat-induced protein glycosylation (3H-D-mannose label), and (3) on thermotolerance expression, using cell survival as an endpoint. Partitioning of label between soluble and insoluble cell fractions was separately examined. Synthesis of high molecular weight HSPs (HSP110, 90, and 72/70) was increased both by acute (10 min, 45 degrees C) and chronic (1-6 h, 41.5 degrees C) hyperthermia, primarily in the soluble cytosol fraction. SDH (10 min, 45 degrees C + 1 to 6 h, 41.5 degrees C) completely inhibited labeling of HSP110, partially inhibited HSP90 labeling, and had virtually no effect on HSP72/70 synthesis, when compared with chronic hyperthermia alone. At the cell survival level, SDH increased sevenfold the rate of cell killing at 41.5 degrees C, but reduced the expression of thermotolerance by only a factor of two. This suggests that SDH sensitization did not result from changes in HSP72/70 synthesis, nor solely from inhibition of thermotolerance. 35S-labeled HSP60 and HSP50 were found primarily in the cellular pellet fraction after both acute and chronic hyperthermia. SDH completely inhibited 35S-labeling of both HSP60 and HSP50. Labeling of GP50 with 3H-D-mannose was also completely inhibited by SDH. Moreover, SDH progressively reduced N-acetylgalactosaminyl-transferase activity. The data demonstrate that heat sensitization by SDH is accompanied by complex and selectively inhibitory patterns of HSP synthesis and protein glycosylation. Profound inhibition of HSP110, HSP60, and HSP50/GP50 labeling suggests that these may be associated with mechanisms of SDH sensitization.  相似文献   

18.
Heat shock proteins and the pancreas   总被引:4,自引:0,他引:4  
Heat shock proteins (HSPs) are cytoprotective molecules that help to maintain the metabolic and structural integrity of cells. In this review, we briefly discuss the regulation and function of HSPs. The review focuses on the current knowledge of pancreatic HSP induction, the HSP level changes during acute pancreatitis, the potential effects of the pre- and co-induction of HSPs in experimental acute pancreatitis, and the mechanisms by which HSPs might mediate cellular protection.  相似文献   

19.
20.

Background and Aims

Heat shock protein (Hsp) 72 is a molecular chaperone which is upregulated in response to a variety of stress situations and has a general cytoprotective function. Increased Hsp72 levels were implicated in protection from acute pancreatitis; a hypothesis which was not tested in a transgenic mouse model yet.

Methods

To analyze the role of Hsp72 during acute pancreatitis, well-characterized transgenic animals overexpressing rat Hsp72 (Hsp72 mice) under the control of the ß-actin promoter were subjected to caerulein- and L-arginine-induced acute pancreatitis. The severity of experimental pancreatitis was determined via serum lipase levels, morphometric evaluation and quantification of pancreatic edema/inflammation.

Results

Hsp72 mice displayed ∼100-times Hsp72 overexpression, but no changes in the remaining chaperones. Robust Hsp72 signal was observed in pancreatic acini, but not in islets or ductal cells. In both models, elevated Hsp72 did not protect from development of acute pancreatitis and the pancreatitis-associated lung injury, but accelerated recovery from caerulein-induced tissue injury (lower lipase levels, edema, inflammation and necrosis 36 h after caerulein administration). The observed protective function of Hsp72 in caerulein-induced pancreatitis is likely due to an attenuated NF-κB signalling.

Conclusions

Hsp72 overexpression accelerates the recovery from acute pancreatitis and may represent a potential treatment strategy.  相似文献   

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