Ethanol and the pancreas

Alcohol and pancreatitis mortality at the population level: experiences from 14 western countries

AIMS

To test if there is relationship between alcohol consumption and pancreatitis mortality at the population level.

DATA AND METHODS

Annual pancreatitis death rates for 1950-95 were converted into age-adjusted mortality rates per 100,000 inhabitants. Per capita alcohol consumption was measured by alcohol sales. The relationship was estimated with time-series analysis on data from 14 western countries. Several models were tested with different assumptions about risk function and lag structure.

RESULTS

According to the assumed most appropriate model, a positive relationship was found in each country, and statistical significance was reached in all countries except from Finland, Italy and Canada. The magnitude of the association was fairly consistent across countries, with the alcohol effect parameters ranging between 0.05 and 0.14. However, Sweden and Norway deviated from this pattern with estimates between 0.30 and 0.40.

CONCLUSIONS

Pancreatitis joins a wide range of causes of death where the mortality rate is influenced by per capita alcohol consumption, and more so in northern Europe. It is suggested that pancreatitis mortality is an important indicator of alcohol-related harm, not least because a large amount of morbidity is likely to be connected to the mortality rate.

Do parotid duct abnormalities occur in patients with chronic alcoholic pancreatitis?

OBJECTIVE

Several studies have suggested that ethanol affects the pancreas and parotid gland. We performed a prospective study to determine whether ductal lesions of ethanol-induced chronic pancreatitis occur in the parotid.

METHODS

Parotid sialograms were performed in 11 alcoholic patients who had endoscopic retrograde pancreatograms. Sialograms and pancreatograms were examined in all subjects for ductal abnormalities.

RESULTS

Seven of nine patients (77.8%) with ductal lesions of the pancreas had coexistent ductal abnormalities of the parotid gland (Kendall's tau = 0.578, p = 0.035).

CONCLUSIONS

Chronic ethanol intake induces ductal alterations in the parotid gland similar to those seen in the pancreas. These results suggest a common histopathological effect of alcohol in the ductal system of the parotid gland and pancreas and raise the possibility that the parotid sialogram could be useful as an adjunct in the diagnosis of ethanol-induced chronic pancreatitis.

Effects of ethanol on the pancreas of disulfiram-treated rats

To study the effects of ethanol on disulfiram-treated rats, we administered ethanol orally at a does of 2000 mg/kg, twice daily for 5 days. The administration of ethanol or disulfiram alone produced no recognizable changes in pancreatic acinar cells. Ethanol administration, in disulfiram-treated rats resulted in a decrease in the content of zymogen granules in acinar cells, and the appearance of intraplasmic vacuolization. Electron microscopically, these vacuoles appeared on the basal side of nuclei. In addition, similar vacuoles appeared in liver cells, and these vacuolizations seemed to show lipid inclusions. However, ethanol administration to disulfiram-treated rats did not cause inflammatory changes or edema in the pancreas. A comparison of blood ethanol levels in rats receiving ethanol alone and disulfiram plus ethanol showed no significant difference, but acetaldehyde levels in rats receiving ethanol plus disulfiram rats were significantly higher than those in rats receiving ethanol alone. These findings suggested that acetaldehyde caused a decrease of zymogen granules and the presence of lipid inclusions in pancreatic acinar cells.

Chronic alcohol consumption intensifies caerulein-induced acute pancreatitis in the rat

Rats were chronically fed either an ethanol-containing diet (36% of total calories derived from alcohol) or a pair-fed, control diet (no alcohol) for 8 wk, and acute pancreatitis (AP) was subsequently induced by a 3-h i.v. infusion of caerulein (CR) at a dose of 5 micrograms/kg/hr. CR-induced AP in control rats (no alcohol) was characterized by a significant elevation in serum lipase content, pancreatic interstitial edema, infrequent occurrences of karyorrhexis, and the appearance of vacuoles in acinar cells. Chronic feeding of the ethanol diet followed by treatment with CR resulted in increases in serum lipase content, interstitial edema, karyorrhexis, and acinar vacuolization that were significantly greater than that seen in rats fed the control diet and treated with CR. It is concluded that chronic ethanol intake in the rat intensifies AP that is subsequently induced by CR.

The role of acetaldehyde in the pathogenesis of acute alcoholic pancreatitis

Acetaldehyde (AA), the first product of ethanol metabolism, has been suggested as an important mediator in alcoholic pancreatitis, but experimental evidence has not been convincing. Prior work using the isolated perfused canine pancreas preparation has suggested that toxic oxygen metabolites generated by xanthine oxidase (XO) may mediate the early injury in pancreatitis. Xanthine oxidase is capable of oxidizing AA, and during this oxidation free radicals are released. The hypothesis that acute alcoholic pancreatitis may be initiated by AA in the presence of active XO (converted from xanthine dehydrogenase [XD]) was tested in the authors' experimental preparation by converting XD to XO by a period of ischemia, and infusing AA. Control preparations remained normal throughout the 4-hour perfusion (weight gain, 7 +/- 4 g; amylase activity, 1162 +/- 202 U/dL). One hour of ischemia or infusion of AA at 25 mg/hr or at 50 mg/hr without ischemia did not induce changes in the preparation. Acetaldehyde at 250 mg/hr induced minimal edema and weight gain (16 +/- 4 g; p less than 0.05), but not significant hyperamylasemia. Changes also were not observed when 1-hour ischemia was followed by a bolus of ethanol (1.5 g) or sodium acetate (3.0 g), or by infusion of 25 mg/hr of AA. One hour of ischemia followed by infusion of AA at 50 mg/hr or at 250 mg/hr induced edema, hemorrhage, weight gain (22 +/- 7 g [p less than 0.05] and 26 +/- 17 g [p less than 0.05]) and hyperamylasemia (2249 +/- 1034 U/dL [p less than 0.05] and 2602 +/- 1412 U/dL [p less than 0.05]). Moreover infusion of AA at 250 mg/hr after 2 hours of ischemia potentiated the weight gain (62 +/- 20 g versus 30 +/- 14 g [p less than 0.05]), but not the hyperamylasemia (3404 +/- 589 U/dL versus 2862 +/- 1525 U/dL) as compared with 2 hours of ischemia alone. Pancreatitis induced by 1 hour of ischemia followed by AA at 50 mg/hr could be inhibited by pretreatment with the free radical scavengers superoxide dismutase and catalase and ameliorated with the XO inhibitor allopurinol. The authors conclude that AA, in the presence of active XO, can initiate acute pancreatitis in the isolated canine pancreas preparation and may be important in the initiation of acute alcoholic pancreatitis in man. Toxic oxygen metabolites appear to play an important intermediary role.

Serum enzymes and other laboratory tests in acute pancreatitis

This review evaluates selective enzymes and blood tests available for the diagnosis and prognosis of acute pancreatitis. It is concluded that serum amylase and lipase measurements represent the best available diagnostic methods. Newer alternative assays still require careful evaluation.

The effect of ethanol on phospholipid metabolism in rat pancreas

The phospholipid effect involves agonist-induced breakdown of phosphatidyl inositol (or polyinositides) generating second messengers followed by increased incorporation of 32P during the resynthetic phase of the cycle. Ethanol, an aetiological factor in pancreatitis, has been shown to have various effects on pancreatic secretion. In this study ethanol decreased the incorporation of 32P into phosphatidyl inositol but had no effect on the stimulated breakdown of prelabelled phosphatidyl inositol. However, in addition to recycling of phosphatidyl inositol stimulation of pancreatic tissue results in increased incorporation of precursors into other phospholipids. Cholecystokinin increased the incorporation of both [U-14C] glucose and 32P into phosphatidyl ethanolamine 3-fold but had no effect on 32P incorporation into phosphatidyl choline. As well as increased incorporation of 32P into phosphatidyl inositol (8-fold) cholecystokinin also increased the incorporation of [U-14C] glucose into phosphatidyl inositol (4-5-fold) implying significant de novo synthesis of 1,2 diacyl glycerol in addition to the currently accepted recycling of the 1,2 diacyl glycerol back to phosphatidyl inositol. Ethanol caused an inhibition of 32P incorporation into total phospholipid of rat pancreas during basal and stimulated conditions. When individual phospholipids were separated ethanol was found to decrease the incorporation of 32P into phosphatidyl choline under basal conditions and into all phospholipids during cholecystokinin stimulation. With [U-14C] glucose as the precursor, ethanol inhibited its incorporation into phosphatidyl choline only. Ethanol did not alter the total 32P radioactivity in the aqueous phase of the pancreatic extract nor the percent incorporated into nucleotides. This excluded decreased uptake of 32P and incorporation into nucleotides as a mechanism for the differential inhibition of 32P versus [U-14C] glucose incorporation into phospholipids other than phosphatidyl choline under stimulated conditions.

Alcohol induced pancreatitis: social and surgical aspects

During the period 1977-1985, 38 patients with alcohol related pancreatitis (37 men, 1 woman) were referred to a specific pancreatic follow-up clinic; their mean age was 42.4 years (range 20-69 years). At initial presentation 14 patients were unemployed (37 per cent) and 11 worked as unskilled labourers (29 per cent). Twenty-seven patients (71 per cent) required more than one hospital admission. Surgery was indicated in 14 patients (37 per cent): 4 diagnostic laparotomy, 3 cholecystectomy, 3 drainage of pancreatic pseudocyst and 1 pancreatic abscess, 3 biliary bypass and 4 pancreatic resection. Four patients required more than one operative procedure. Five deaths occurred during the study period: one following biliary bypass, one following total pancreatectomy and three not directly related to pancreatitis. Follow-up attendance rates at 1, 3 and 5 years were 76, 47 and 34 per cent respectively. Alcohol induced pancreatitis in Teesside, UK, is a disease of young adult males of lower socio-economic status with a recurring pattern leading to repeated hospital admissions and an unexpectedly high incidence of surgery. The study demonstrates the problem of ascertaining data related to long term follow-up in a condition where, despite intensive efforts, patient compliance is poor.

Raised serum concentrations of pancreatic enzymes in cigarette smokers

Circulating concentrations of digestive enzymes, certain lysosomal hydrolases and protease inhibitors were measured in 19 heavy smokers and 13 non-smokers before (basal) and at 15, 30, and 60 minutes after a single intravenous injection of secretin (75 CU). In smokers, basal serum amylase and immunoreactive pancreatic elastase 2 (IRE2) concentrations were about 100% and 25% higher respectively, than in the non-smokers, whereas, no differences were observed in basal immunoreactive cationic trypsinogen (IRCT) concentrations and in acid phosphatase and beta-glucuronidase activities between the two groups. Furthermore, a single injection of secretin to cigarette smokers significantly increased serum amylase, IRCT and IRE2 by 155%, 200%, and 100%, respectively when compared with their corresponding basal levels. No such increment was observed in the non-smokers. In addition, there were no significant differences in serum trypsin or elastase inhibitory capacity or immunoreactive alpha 1-protease inhibitor and alpha 2-macroglobulin levels between smokers and non-smokers. The levels and inhibitory capacity of these protease inhibitors was also not affected by secretin injection. These data suggest that cigarette smoking enhances the responsiveness of the exocrine pancreas to a physiological stimulus such as secretin, with resultant substantial increase in the concentrations of pancreatic hydrolases in blood.

Serum malanodialdehyde (TBA reactive substance) levels in cigarette smokers

Serum malanodialdehyde (MDA) levels in 40 smokers and 23 non-smokers belonging to different age groups were estimated. The MDA levels were high in smokers of all age groups having a history of smoking for less than 10 years. MDA levels, however, were not elevated in smokers with a history of smoking for more than 10 years. These results are discussed and are interpreted as suggestive that MDA might alter the LDL and lead to deposition of cholesterol in arterial wall macrophages explaining thereby the risk of ischaemic heart disease in cigarette smokers.

Long-term ethanol ingestion causes an increase of phospholipase A2 activity in acute experimental pancreatitis in rats

Alcohol is recognized as one etiological factor in pancreatitis and according to recent studies, phospholipase A2 (PLA2) may be an important factor in the pathogenesis of this disease. However, the effect of chronic ethanol ingestion on PLA2 activity has not been studied in pancreatitis. To clarify the possible relation of these two factors 48 male Wistar rats received 15% (v/v) ethanol in drinking water for 12 weeks and 48 rats served as controls drinking tap water. Blood samples were collected from the control animals by puncturing the abdominal aorta. Experimental pancreatitis was induced by intraductal retrograde infusion of normal rat bile and blood samples collected 24 hr after the infusion. PLA2 activities in the plasma were measured by using the substrate with a 3H-labeled fatty acid in position 2. PLA2 activities in the control group were 11.2 +/- 1.3 (mean +/- SE) nmole/ml/min and 21.7 +/- 3.5 twenty-four hours later (P less than 0.05). In alcoholic rats the activities were 11.1 +/- 1.4 and 54.0 +/- 10.3, respectively (P less than 0.003). The increase of the activities was greater in alcoholic rats and the difference between the groups statistically significant (P less than 0.025). The mortality rate was 4.2% among the control animals and 29.2% in the alcoholic groups (P less than 0.026). The results of this study suggest that chronic alcohol ingestion makes the pancreas vulnerable to severe pancreatitis with high mortality. This is associated with significantly increased activities of PLA2.

Occupational chemicals and pancreatitis: a link?

The rising trend of idiopathic pancreatitis, and our demonstration that cytochromes P450 are 'induced' in most patients, prompted a search for enzyme inducers in their work environments. The findings in 19 patients (chronic pancreatitis 15, acute pancreatitis 4) are described. In the initial series of 12 consecutive patients with idiopathic pancreatitis, the enquiry revealed regular exposure to diesel exhaust fumes in 6 patients (of whom one had also been exposed to ozone and metal oxides), perchloroethylene or trichloroethylene in 3, paint solvents in a further 3. A second series included the next 7 patients with pancreatitis who drank alcohol on a daily basis for several years before their first symptom, but whose attacks continued although they had become, and remained, teetotal: their current occupations involved regular exposure to diesel exhaust fumes in 5 patients, to paint solvents in 1, and to trichloroethylene in 1. The wide variation in the duration of exposure before the first symptom, 2-21 yr, may reflect the net effect on cytochromes P450 of other xenobiotics (e.g. alcohol, cigarettes, caffeine). In several patients, symptoms stopped on removal from exposure to volatile chemicals but recurred on re-exposure. These preliminary findings suggest that occupational exposure to aromatic or chlorinated hydrocarbons may be relevant not only in idiopathic pancreatitis but also in alcohol-related pancreatic disease.

Induction of cytochromes P-450 in pancreatic disease: consequence, coincidence or cause?

We have examined the pharmacokinetics of antipyrine and of theophylline--validated probes for cytochromes P-450 activities--in a series of patients with pancreatic disease. The half-life of each drug was significantly lower, and its clearance faster, in patients than in controls and this pattern was detected in the subgroups with acute pancreatitis (6), chronic pancreatitis (22), or pancreatic cancer (4). These data suggest induction of cytochromes P-450 in all forms of exocrine pancreatic disease. Enzyme induction is unlikely to be secondary to pancreatic malfunction since there was no correlation between prevailing exocrine status, as assessed by secretin-pancreozymin tests, and the half-life or clearance of either drug. The corollary is that induction of the mono-oxygenases by environmental agents, both recognised and unidentified, is a primary event in pancreatic disease. The possible relevance of this finding is discussed.

Irreversible inhibition by acetaldehyde of cholecystokinin-induced amylase secretion from isolated rat pancreatic acini

Acetaldehyde inhibited both amylase secretion induced by maximal concentrations (300 pM) of cholecystokinin octapeptide and the binding of radioiodinated cholecystokinin to receptors on isolated rat pancreatic acini. This inhibition was concentration dependent (10 mM to 1 M for amylase secretion and 100 mM to 1 M for binding). However, a correlation between the two inhibitory effects could not be obtained. Furthermore, the inhibitory effects were not reversible. Acetaldehyde did not alter the basal amylase secretion between 6 and 45 mM concentrations. However, 60, 100 and 300 mM acetaldehyde significantly decreased basal amylase secretion; no significant change in amylase secretion was observed at 600 mM and 1 M. Higher concentrations of acetaldehyde produced a 2- to 10-fold increase in basal amylase secretion. 51Cr release from prelabeled acini revealed no significant cell membrane damage between 10 and 600 mM acetaldehyde. These data suggest that acetaldehyde inhibition of cholecystokinin-induced amylase secretion is intracellularly mediated.