Does chronic ethanol intake cause chronic pancreatitis?: evidence and mechanism

How Alcohol Induces Human Acute Alcoholic Pancreatitis-Problem Solved?

It has been a puzzle why only a minority of heavy alcohol drinkers develop acute alcoholic pancreatitis. In this review, the sparse data available from published studies were collected and, based on them, a hypothesis was formed. Long-term high alcohol consumption results in lowered cholecystokinin and cholinergic stimulus of the pancreas, and causes concentration and acidification of pancreatic fluid, predisposing to protein secretion. Early during the withdrawal period when returning to a normal or high-fat nonalcoholic diet, there is a relative hyperstimulation of the pancreas, a well-established mechanism that results in experimental acute pancreatitis. Lower, physiological stimulation is enough to start acute pancreatitis, when the secretions cause temporary obstruction in the duct system; the stimulation against temporary obstruction is also well-known to result in experimental acute pancreatitis. The magnitude of alcohol-induced deficits in acinar cell defense mechanisms then finally determines the onset of pancreatitis.

Targeted animal models for preclinical assessment of cellular and gene therapies in pancreatic and liver diseases: regulatory and practical insights

Cellular and gene therapy (CGT) products have emerged as a popular approach in regenerative medicine, showing promise in treating various pancreatic and liver diseases in numerous clinical trials. Before these therapies can be tested in human clinical trials, it is essential to evaluate their safety and efficacy in relevant animal models. Such preclinical testing is often required to obtain regulatory approval for investigational new drugs. However, there is a lack of detailed guidance on selecting appropriate animal models for CGT therapies targeting specific pancreatic and liver conditions, such as pancreatitis and chronic liver diseases. In this review, the gastrointestinal committee for the International Society for Cell and Gene Therapy provides a summary of current recommendations for animal species and disease model selection, as outlined by the US Food and Drug Administration, with references to EU EMA and Japan PMDA. We discuss a range of small and large animal models, as well as humanized models, that are suitable for preclinical testing of CGT products aimed at treating pancreatic and liver diseases. For each model, we cover the associated pathophysiology, commonly used metrics for assessing disease status, the pros and limitations of the models, and the relevance of these models to human conditions. We also summarize the use and application of humanized mouse and other animal models in evaluating the safety and efficacy of CGT products. This review aims to provide comprehensive guidance for selecting appropriate animal species and models to help bridge the gap between the preclinical research and clinical trials using CGT therapies for specific pancreatic and liver diseases.

Repeated Stimulation of Toll-Like Receptor 2 and Dectin-1 Induces Chronic Pancreatitis in Mice Through the Participation of Acquired Immunity

BACKGROUND

Stimulation of Toll-like receptor 3 (TLR3) induces autoimmune-mediated pancreatitis in susceptible mice, whereas stimulation of TLR4 causes nonautoimmune-mediated pancreatitis. However, the effects of TLR2 stimulation on the pancreas are unknown.

AIMS

We investigated the role of TLR2 stimulation on pancreatic damage by repeatedly stimulating mice with TLR2 ligands.

METHODS

Wild-type (WT) and interleukin 10-deficient (IL-10-knockout (KO)) mice were administered zymosan and lipoteichoic acid (LTA) intraperitoneally at various doses twice weekly for 4 weeks. Syngeneic T-cell-deficient mice, B-cell-deficient mice, recombination activating gene 2-deficient (RAG2-KO) mice and RAG2-KO mice that had been reconstituted with CD4⁺ or CD8⁺ T cells isolated from WT mice were treated with zymosan similarly. Mice were killed, the severity of pancreatitis was graded histologically, and serum cytokine levels were measured.

RESULTS

Repeated administration of zymosan induced pancreatitis dose dependently in both WT and IL-10-KO mice. Administration of LTA induced pancreatitis only in IL-10-KO mice. Adoptive transfer of splenocytes obtained from IL-10-KO mice with pancreatitis did not cause pancreatitis in recipient RAG2-KO mice. Pancreatitis was scarcely observed in RAG2-KO mice and was attenuated in T-cell-deficient and B-cell-deficient mice compared with WT mice. A single administration of zymosan significantly increased the serum level of monocyte chemoattractant protein 1 (MCP-1) in WT mice.

CONCLUSIONS

Repeated stimulation of TLR2 and dectin-1 induced nonautoimmune-mediated pancreatitis in mice. Participation of acquired immunity seems to play an important role in the pathogenesis of pancreatitis in association with the increase in serum MCP-1 level.

Genetically induced vs. classical animal models of chronic pancreatitis: a critical comparison

Chronic pancreatitis (CP) is an utmost complex disease that is pathogenetically linked to pancreas-intrinsic ( e.g., duct obstruction), environmental-toxic ( e.g., alcohol, smoking), and genetic factors. Studying such a complex disease naturally requires validated experimental models. In the past 2 decades, the various animal models of CP usually addressed either the pancreas-intrinsic ( e.g., the caerulein model), the environmental-toxic ( e.g., diet-induced models), or the genetic component of CP. As such, these models were far from mirroring CP in its full spectrum, and the correct choice of models was vital for valid scientific conclusions on CP. The quest for mechanistic, genetic models gave rise to models based on gene modification and transgene insertion, such as the PRSS1 and the IL-1β/IL-1β models. Recently, we witnessed the development of highly exciting models that rely on the importance of autophagy in CP, that is, the murine pancreas-specific Atg5 and LAMP2 knockout models. Today, critical comparison of these several models is more important than ever for guiding research on CP in an efficient direction. The present review outlines the characteristics of the new genetic models in comparison with the well-known classic models for CP, notes the caveats in the choice of models, and also indicates novel directions for model development.-Klauss, S., Schorn, S., Teller, S., Steenfadt, H., Friess, H., Ceyhan, G. O., Demir, I. K. Genetically induced vs. classical animal models of chronic pancreatitis: a critical comparison.

Animal models of gastrointestinal and liver diseases. Animal models of acute and chronic pancreatitis

Animal models of pancreatitis are useful for elucidating the pathogenesis of pancreatitis and developing and testing novel interventions. In this review, we aim to summarize the most commonly used animal models, overview their pathophysiology, and discuss their strengths and limitations. We will also briefly describe common animal study procedures and refer readers to more detailed protocols in the literature. Although animal models include pigs, dogs, opossums, and other animals, we will mainly focus on rodent models because of their popularity. Autoimmune pancreatitis and genetically engineered animal models will be reviewed elsewhere.

Betaine Attenuates Alcohol-Induced Pancreatic Steatosis

OBJECTIVES

To explore the effect of betaine on alcoholic pancreatic steatosis and its mechanism.

METHODS

Rats were randomly assigned to control, ethanol, or ethanol + betaine groups. Changes in pancreatic morphology; serum lipid levels; and pancreatic lipid, amylase and lipase levels were determined. The serum and adipose tissue adiponectin level was measured by an enzyme-linked immunoassay. Adiponectin receptor-1 (AdipoR1), AdipoR2, sterol regulatory element binding protein-1c (SREBP-1c), SREBP-2, and fatty acid synthetase expression levels were quantified. The SREBP-1c expression in SW1990 cells treated with various concentrations of ethanol or ethanol plus betaine and/or adiponectin was assessed.

RESULTS

Alcohol-induced changes in pancreatic morphology were attenuated by betaine. Pancreatic triglyceride, free fatty acid and expression levels of SREBP-1c and fatty acid synthetase were elevated after ethanol feeding but remained at control levels after betaine supplementation. Alcohol-induced decreases in serum and adipose tissue adiponectin, pancreatic AdipoR1, amylase, and lipase were attenuated by betaine. Serum triglyceride and free fatty acid levels were elevated after alcohol consumption and remained higher after betaine supplementation compared with controls. Betaine and/or adiponectin suppressed alcohol-induced SREBP-1c upregulation in vitro.

CONCLUSIONS

Betaine attenuated alcoholic-induced pancreatic steatosis most likely by suppressing pancreatic SREBP-1c both directly and through the restoration of adiponectin signaling.

Pathophysiology of chronic pancreatitis induced by dibutyltin dichloride joint ethanol in mice

AIM

To search for a new chronic pancreatitis model in mice suitable for investigating the pathophysiological processes leading to pancreatic fibrosis.

METHODS

The mice were randomly divided into 2 groups (n = 50), control group and model group. The mice in model group were given ethanol (10%) in drinking water after injection of dibutyltin dichloride (DBTC) (8 mg/kg BW) in tail vein. The mice in control group were injected with only solvent into tail vein (60% ethanol, 20% glycerine and 20% normal saline) and drank common water. At days 1, 7, 14, 28, and 56 after application of DBTC or solvent, 10 mice in one group were killed at each time point respectively. Blood was obtained by inferior vena cava puncture. The activity of amylase, concentration of bilirubin and hyaluronic acid in serum were assayed. The pancreas was taken to observe the pancreatic morphology by HE staining, and to characterize the pancreatic fibrosis by Masson staining. The expression of F4/80, CD3 and fibronectin (FN) were assayed by immuno-histochemistry or Immunofluorescence technique. Collagen type I (COL1A1) in pancreas were detected by Western blot. The expression of matrix metalloproteinase-1 (MMP-1) and tissue inhibitor of metalloproteinases-1 (TIMP-1) mRNA in the pancreas was assessed by real time PCR.

RESULTS

DBTC induced an acute edematous pancreatitis within 1 d. The dilated acini, scattered acinar cell necrosis, and inflammatory cells were found at day 7. Extensive infiltration with inflammatory cells following deposition of connective tissue was observed at day 14. At day 28, level of pancreatic fibrosis was aggravated. The pancreatic tissue was replaced by an extended interstitial fibrosis at the end of 2 mo. There was significant difference in the level of amylase, bilirubin and hyaluronic acid in serum between control group and model group (P < 0.05). The level of COL1A1 and FN in pancreas increased. The expression of MMP-1 mRNA in pancreas decreased, but TIMP-1 mRNA increased at model group.

CONCLUSION

DBTC joint Ethanol drinking can induce chronic pancreatitis in accordance with the pathophysiological modification of human. DBTC joint Ethanol-induced pancreatitis in mice is an effective and handy experimental method. The model is suitable to study the mechanism of pancreatic fibrosis in chronic pancreatitis.

Pharmacological attenuation of chronic alcoholic pancreatitis induced hypersensitivity in rats

AIM

To characterize an alcohol and high fat diet induced chronic pancreatitis rat model that mimics poor human dietary choices.

METHODS

Experimental rats were fed a modified Lieber-DeCarli alcohol (6%) and high-fat (65%) diet (AHF) for 10 wk while control animals received a regular rodent chow diet. Weekly behavioral tests determined mechanical and heat sensitivity. In week 10 a fasting glucose tolerance test was performed, measuring blood glucose levels before and after a 2 g/kg bodyweight intraperitoneal (i.p.) injection of glucose. Post mortem histological analysis was performed by staining pancreas and liver tissue sections with hematoxylin and eosin. Pancreas sections were also stained with Sirius red and fast green to quantify collagen content. Insulin-expressing cells were identified immunohistochemically in separate sections. Tissue staining density was quantified using Image J software. After mechanical and heat sensitivity became stable (weeks 6-10) in the AHF-fed animals, three different drugs were tested for their efficacy in attenuating pancreatitis associated hypersensitivity: a Group II metabotropic glutamate receptor specific agonist (2R,4R)-4-Aminopyrrolidine-2,4-dicarboxylate (APDC, 3 mg/kg, ip; Tocris, Bristol, United Kingdom), nociceptin (20, 60, 200 nmol/kg, ip; Tocris), and morphine sulfate (3 mg/kg, μ-opioid receptor agonist; Baxter Healthcare, Deerfield, IL, United States).

RESULTS

Histological analysis of pancreas and liver determined that unlike control rats, AHF fed animals had pancreatic fibrosis, acinar and beta cell atrophy, with steatosis in both organs. Fat vacuolization was significantly increased in AHF fed rats (6.4% ± 1.1% in controls vs 23.8% ± 4.2%, P < 0.05). Rats fed the AHF diet had reduced fasting glucose tolerance in week 10 when peak blood glucose levels reached significantly higher concentrations than controls (127.4 ± 9.2 mg/dL in controls vs 161.0 ± 8.6 mg/dL, P < 0.05). This concurred with a 3.5 fold higher incidence of single and small 2-10 cell insulin-positive cell clusters (P < 0.05). Insulin expressing islet of Langerhans cells appeared hypertrophied while islet number and area measurements were not different from controls. Weekly behavioral tests determined that mechanical and heat sensitivities were significantly increased by 4 wk on AHF diet compared to controls. Hypersensitivity was attenuated with efficacy similar to morphine with single dose treatment of either metabotropic glutamate receptor 2/3 agonist APDC, or nociceptin, the endogenous ligand for opioid-receptor-like 1 receptor.

CONCLUSION

The AHF diet induces a chronic alcoholic pancreatitis in rats with measurable features resembling clinical patients with chronic pancreatitis and type 3c diabetes mellitus.

The conspiracy of autophagy, stress and inflammation in acute pancreatitis

PURPOSE OF REVIEW

Acute pancreatitis is associated with alcohol abuse, gallstones and bacterial infection. Its basic cause is tissue destruction accompanied by an innate immune response, which induces epithelial stress pathways. Recent studies have focused on some of the integral cellular pathways shared between multiple pancreatitis models that also suggest new approaches to detection and treatment.

RECENT FINDINGS

Several models of pancreatitis have been associated with stress responses, such as endoplasmic reticulum and oxidative stress together with the induction of a defective autophagic pathway. Recent evidence reinforces the critical role of these cellular processes in pancreatitis. A member of the toll-like receptor family, toll-like receptor 4, which is known to contribute to disease pathology in many models of experimental pancreatitis, has been found to be a promising target for treatment of pancreatitis. Interestingly, a direct activator of toll-like receptor 4, the bacterial cell wall component in gram-negative bacteria lipopolysaccharide, contributes to the onset and severity of disease when combined with additional stressors, such as chronic alcohol feeding; however, recent studies have shown that acute infection of mice with live bacteria is alone sufficient to induce acute pancreatitis.

SUMMARY

In the last several months, the convergent roles of acinar cell stress, autophagy and proinflammatory signaling initiated by the toll-like receptors have been emphatically reinforced in the onset of acute pancreatitis.

Acquired immunity plays an important role in the development of murine experimental pancreatitis induced by alcohol and lipopolysaccharide

OBJECTIVE

Although chronic alcohol ingestion is the major cause of chronic pancreatitis, less than 10% of alcohol abusers develop this disease. To address this issue, we created a murine model of pancreatitis induced by alcohol and lipopolysaccharide (LPS) and analyzed its immune responses.

METHODS

C57BL/6 mice were administered 20% ethanol (AL) in their drinking water and then injected intraperitoneally with LPS twice weekly for 4 weeks. Severe combined immunodeficient mice were reconstituted with splenocytes, CD4 cells, or CD8 T cells isolated from wild-type mice and then treated similarly. The severity of pancreatitis was graded histologically, and serum cytokine levels were measured.

RESULTS

Ethanol alone did not cause pancreatitis. However, the administration of AL+LPS or LPS alone induced pancreatitis. The histological scores were higher in the mice treated with AL+LPS than in those treated with LPS. Serum levels of interleukin 1β, interferon-γ, and tumor necrosis factor α were elevated in the AL+LPS-treated mice. The severe combined immunodeficient mice developed pancreatitis only after their reconstitution with splenocytes, CD4 cells, or CD8 T cells.

CONCLUSIONS

Repeated stimulation of the innate immune system is necessary, but not sufficient, to cause pancreatitis. The participation of the acquired immune response is essential for the development of the disease.

A review of animal models of nonneoplastic pancreatic diseases

The nonneoplastic diseases of the human pancreas generally comprise the inflammatory and degenerative conditions that include acute and chronic pancreatitis, with cystic fibrosis being arguably one of the most important diseases that induce the condition. Both acute and chronic conditions vary in severity, but both can be life threatening; and because of this fact, the study of their progression, and their responsiveness to therapy, is largely conducted by indirect means using serum markers of damage and repair such as amylase and lipase activities that normally occur at very low levels in the circulation but can be significantly increased during inflammatory episodes. Progress in the understanding the pathogenesis of both conditions has therefore been largely due to time course studies in animal models of pancreatitis, and it is in this context that animal model development has been so significant. In general terms, the animal models can be divided into the invasive, surgical procedures, and those induced by the administration of chemical secretagogues that induce hypersecretion of the pancreatic enzymes. The former include ligation and/or cannulation of the biliopancreatic ducts with infusion of solutions of various kinds, or the formation of closed duodenal loops. Secretagogue administration includes administration of caerulein or l-arginine in various protocols. An additional model involves administration of dibutyltin dichloride, which induces a partial blockage of the pancreatic ducts to induce pancreatic disease through enzymic reflux into the gland. The models have been invaluable in generating testable hypotheses for the human diseases. These hypotheses for the production of cellular damage as the initiating events in the disease include (1) intracellular chemical activation, (2) pancreatic secretion reflux, (3) intracellular production of reactive oxygen species, and (4) intracellular production of free radicals.

Cerulein-induced chronic pancreatitis does not require intra-acinar activation of trypsinogen in mice

BACKGROUND & AIMS

Premature activation of trypsinogen activation can cause pancreatic injury and has been associated with chronic pancreatitis (CP). Mice that lack intra-acinar activation of trypsinogen, such as trypsinogen-7-null (T(-/-)) and cathepsin B-null (CB(-/-)) mice, have been used to study trypsin-independent processes of CP development. We compared histologic features and inflammatory responses of pancreatic tissues from these mice with those from wild-type mice after the development of CP.

METHODS

CP was induced in wild-type, T(-/-), and CB(-/-) mice by twice-weekly induction of acute pancreatitis for 10 weeks; acute pancreatitis was induced by hourly intraperitoneal injections of cerulein (50 μg/kg × 6). Pancreatic samples were collected and evaluated by histologic and immunohistochemical analyses. Normal human pancreas samples, obtained from the islet transplant program at the University of Minnesota, were used as controls and CP samples were obtained from surgical resections.

RESULTS

Compared with pancreatic tissues from wild-type mice, those from T(-/-) and CB(-/-) mice had similar levels of atrophy, histomorphologic features of CP, and chronic inflammation. All samples had comparable intra-acinar activation of nuclear factor (NF)-κB, a transcription factor that regulates the inflammatory response, immediately after injection of cerulein. Pancreatic tissue samples from patients with CP had increased activation of NF-κB (based on nuclear translocation of p65 in acinar cells) compared with controls.

CONCLUSIONS

Induction of CP in mice by cerulein injection does not require intra-acinar activation of trypsinogen. Pancreatic acinar cells of patients with CP have increased levels of NF-κB activation compared with controls; regulation of the inflammatory response by this transcription factor might be involved in the pathogenesis of CP.

Alcohol consumption on pancreatic diseases

Although the association between alcohol and pancreatic diseases has been recognized for a long time, the impact of alcohol consumption on pancreatitis and pancreatic cancer (PC) remains poorly defined. Nowadays there is not consensus about the epidemiology and the beverage type, dose and duration of alcohol consumption causing these diseases. The objective of this study was to review the epidemiology described in the literature for pancreatic diseases as a consequence of alcoholic behavior trying to understand the association between dose, type and frequency of alcohol consumption and risk of pancreatitis and PC. The majority of the studies conclude that high alcohol intake was associated with a higher risk of pancreatitis (around 2.5%-3% between heavy drinkers and 1.3% between non drinkers). About 70% of pancreatitis are due to chronic heavy alcohol consumption. Although this incidence rate differs between countries, it is clear that the risk of developing pancreatitis increases with increasing doses of alcohol and the average of alcohol consumption vary since 80 to 150 g/d for 10-15 years. With regard to PC, the role of alcohol consumption remains less clear, and low to moderate alcohol consumption do not appear to be associated with PC risk, and only chronic heavy drinking increase the risk compared with lightly drinkers. In a population of 10%-15% of heavy drinkers, 2%-5% of all PC cases could be attributed to alcohol consumption. However, as only a minority (less than 10% for pancreatitis and 5% for PC) of heavily drinkers develops these pancreatic diseases, there are other predisposing factors besides alcohol involved. Genetic variability and environmental exposures such as smoking and diet modify the risk and should be considered for further investigations.

Alcohol consumption and pancreatic cancer: a pooled analysis in the International Pancreatic Cancer Case-Control Consortium (PanC4)

BACKGROUND

Heavy alcohol drinking has been related to pancreatic cancer, but the issue is still unsolved.

METHODS

To evaluate the role of alcohol consumption in relation to pancreatic cancer, we conducted a pooled analysis of 10 case-control studies (5585 cases and 11,827 controls) participating in the International Pancreatic Cancer Case-Control Consortium. We computed pooled odds ratios (ORs) by estimating study-specific ORs adjusted for selected covariates and pooling them using random effects models.

RESULTS

Compared with abstainers and occasional drinkers (< 1 drink per day), we observed no association for light-to-moderate alcohol consumption (≤ 4 drinks per day) and pancreatic cancer risk; however, associations were above unity for higher consumption levels (OR = 1.6, 95% confidence interval 1.2-2.2 for subjects drinking ≥ 9 drinks per day). Results did not change substantially when we evaluated associations by tobacco smoking status, or when we excluded participants who reported a history of pancreatitis, or participants whose data were based upon proxy responses. Further, no notable differences in pooled risk estimates emerged across strata of sex, age, race, study type, and study area.

CONCLUSION

This collaborative-pooled analysis provides additional evidence for a positive association between heavy alcohol consumption and the risk of pancreatic cancer.

Animal models for investigating chronic pancreatitis

Chronic pancreatitis is defined as a continuous or recurrent inflammatory disease of the pancreas characterized by progressive and irreversible morphological changes. It typically causes pain and permanent impairment of pancreatic function. In chronic pancreatitis areas of focal necrosis are followed by perilobular and intralobular fibrosis of the parenchyma, by stone formation in the pancreatic duct, calcifications in the parenchyma as well as the formation of pseudocysts. Late in the course of the disease a progressive loss of endocrine and exocrine function occurs. Despite advances in understanding the pathogenesis no causal treatment for chronic pancreatitis is presently available. Thus, there is a need for well characterized animal models for further investigations that allow translation to the human situation. This review summarizes existing experimental models and distinguishes them according to the type of pathological stimulus used for induction of pancreatitis. There is a special focus on pancreatic duct ligation, repetitive overstimulation with caerulein and chronic alcohol feeding. Secondly, attention is drawn to genetic models that have recently been generated and which mimic features of chronic pancreatitis in man. Each technique will be supplemented with data on the pathophysiological background of the model and their limitations will be discussed.

Chronic pancreatitis

Chronic pancreatitis is a progressive fibroinflammatory disease that exists in large-duct (often with intraductal calculi) or small-duct form. In many patients this disease results from a complex mix of environmental (eg, alcohol, cigarettes, and occupational chemicals) and genetic factors (eg, mutation in a trypsin-controlling gene or the cystic fibrosis transmembrane conductance regulator); a few patients have hereditary or autoimmune disease. Pain in the form of recurrent attacks of pancreatitis (representing paralysis of apical exocytosis in acinar cells) or constant and disabling pain is usually the main symptom. Management of the pain is mainly empirical, involving potent analgesics, duct drainage by endoscopic or surgical means, and partial or total pancreatectomy. However, steroids rapidly reduce symptoms in patients with autoimmune pancreatitis, and micronutrient therapy to correct electrophilic stress is emerging as a promising treatment in the other patients. Steatorrhoea, diabetes, local complications, and psychosocial issues associated with the disease are additional therapeutic challenges.

Irreversible exocrine pancreatic insufficiency in alcoholic rats without chronic pancreatitis after alcohol withdrawal

BACKGROUND

Long-term alcohol consumption alone did not cause chronic pancreatitis (CP) but impaired exocrine pancreatic function. This study is to explore the reversibility of exocrine pancreatic insufficiency in the abstinent rats and its mechanism.

METHODS

Forty-eight healthy male Wistar rats were divided randomly into 4 groups: 6-month control, 6-month ethanol, 9-month control, and 9-month ethanol + withdrawal. Morphological changes of pancreatic acinar cells were observed. Pancreatic amylase and lipase were measured using an automatic biochemical analyzer. Free fatty acid (FFA) in rat intestinal chyme was measured. Cholecystokinin (CCK) levels were determined by radioimmunoassay. The expression of CCK-A receptors was quantitatively analyzed by Western blot.

RESULTS

Alcohol-induced ultramicrostructure changes of pancreatic acinar cells, including lipid droplets, myelinoid inclusion bodies, dilated rough endoplasmic reticulums, and diminished zymogen granules, were not attenuated after alcohol abstinence. The outputs of amylase and lipase, FFA content in intestinal chyme, and the intestinal and the pancreatic CCK levels in rats were reduced after chronic alcohol intake and were still lower than the control after cessation of alcohol use. Chronic ethanol intake or abstinence did not induce any change in the expression of CCK-A receptors.

CONCLUSIONS

Exocrine pancreatic insufficiency was irreversible in alcoholic rats without CP after alcohol withdrawal. It may be attributed to reduced pancreatic CCK, long-standing fatty infiltration, ultramicrostructure injuries in pancreatic acinar cells, and aging.

Cholinergic mediation of alcohol-induced experimental pancreatitis

OBJECTIVES

The mechanisms initiating pancreatitis in patients with chronic alcohol abuse are poorly understood. Although alcohol feeding has been previously suggested to alter cholinergic pathways, the effects of these cholinergic alterations in promoting pancreatitis have not been characterized. For this study, we determined the role of the cholinergic system in ethanol-induced sensitizing effects on cerulein pancreatitis.

METHODS

Rats were pair-fed control and ethanol-containing Lieber-DeCarli diets for 6 weeks followed by parenteral administration of 4 hourly intraperitoneal injections of the cholecystokinin analog, cerulein at 0.5 μg/kg. This dose of cerulein was selected because it caused pancreatic injury in ethanol-fed but not in control-fed rats. Pancreatitis was preceded by treatment with the muscarinic receptor antagonist atropine or by bilateral subdiaphragmatic vagotomy. Measurement of pancreatic pathology included serum lipase activity, pancreatic trypsin, and caspase-3 activities, and markers of pancreatic necrosis, apoptosis, and autophagy. In addition, we measured the effects of ethanol feeding on pancreatic acetylcholinesterase activity and pancreatic levels of the muscarinic acetylcholine receptors m1 and m3. Finally, we examined the synergistic effects of ethanol and carbachol on inducing acinar cell damage.

RESULTS

We found that atropine blocked almost completely pancreatic pathology caused by cerulein administration in ethanol-fed rats, while vagotomy was less effective. Ethanol feeding did not alter expression levels of cholinergic muscarinic receptors in the pancreas but significantly decreased pancreatic acetylcholinesterase activity, suggesting that acetylcholine levels and cholinergic input within the pancreas can be higher in ethanol-fed rats. We further found that ethanol treatment of pancreatic acinar cells augmented pancreatic injury responses caused by the cholinergic agonist, carbachol.

CONCLUSION

These results demonstrate key roles for the cholinergic system in the mechanisms of alcoholic pancreatitis.

The role of alcohol and smoking in pancreatitis

Chronic alcohol use has been linked to chronic pancreatitis for over a century, but it has not been until the last decade that the role of alcohol in chronic pancreatitis has been elucidated in animals and, only in recent years, in human populations. Although a dose-dependent association between alcohol consumption and chronic pancreatitis may exist, a staistical association has been shown only with the consumption of >or=5 alcoholic drinks per day. Smoking also confers a strong, independent and dose-dependent risk of pancreatitis that may be additive or multiplicative when combined with alcohol. Alcohol increases the risk of acute pancreatitis in several ways and, most importantly, changes the immune response to injury. Genetic factors are also important and further studies are needed to clarify the role of gene-environment interactions in pancreatitis. In humans, aggressive interventional counseling against alcohol use may reduce the frequency of recurrent attacks of disease and smoking cessation may help to slow the progression of acute to chronic pancreatitis.

Pancreas and liver injury are associated in individuals with increased alcohol consumption

BACKGROUND & AIMS

Although chronic pancreatitis and liver cirrhosis are common sequelae of excess alcohol consumption, the 2 conditions are rarely associated. We studied the prevalence of simultaneous liver cirrhosis and chronic pancreatitis in alcoholics.

METHODS

Postmortem autopsy data from 620 individuals with a history of excess alcohol consumption and 100 nonalcoholics (controls) were analyzed. The individuals were classified into groups based on macroscopic observations of pancreas (no injury, acute pancreatitis, fibrosis, and chronic pancreatitis) and liver (no injury, moderate steatosis, severe steatosis, and cirrhosis). The same classification system was used for histological data, which was used to confirm and correlate macroscopic results.

RESULTS

Out of the 183 patients with liver cirrhosis, 33 (18%) had chronic pancreatitis and 93 (51%) had pancreatic fibrosis. Out of the 230 patients with severe steatosis, 37 (16%) had chronic pancreatitis and 97 (42%) were found to have a pancreatic fibrosis. Thirty-three (39%) with chronic pancreatitis also showed liver cirrhosis and 37 (44%) showed severe steatosis. Thirty-eight percent of the patients with a pancreatic fibrosis were found also to have liver cirrhosis and in another 40% severe steatosis. Thirty-five patients showed neither hepatic or pancreatic injury. We found no chronic pancreatitis or liver cirrhosis in the control group (n = 100).

CONCLUSIONS

Contrary to common belief there is a close association between pancreatic and hepatic injury in patients with increased alcohol consumption, and the degree of organ damage between the 2 organs correlate.