Elevated serum levels of pancreatic secretory proteins in cigarette smokers after secretin stimulation

Analysis of Factors Associated with the Severity of Acute Pancreatitis according to Etiology

Background

The objective of this study was to determine the factors associated with severity of acute pancreatitis (AP) according to two major etiologies: alcohol and gallstones.

Methods

We reviewed the medical records of consecutive patients who were admitted with AP between January 2003 and January 2013. A total of 905 patients with AP (660 alcohol-induced, 245 gallstone-induced) were enrolled. Among them, severe AP (SAP) occurred in 72 patients (53 alcohol-induced, 19 gallstone-induced). Contributing factors between patients with and without SAP were analyzed according to the etiology.

Results

Multivariate analysis demonstrated that current smoking, pancreatic necrosis, and bacteremia were associated with AP severity in both alcohol- and gallstone-induced AP. Pancreatic fluid collection was significantly associated with alcohol-induced SAP (p = 0.04), whereas dyslipidemia was significantly associated with gallstone-induced SAP (p = 0.01). Body mass index was significantly correlated with the Bedside Index of Severity in Acute Pancreatitis score in both alcohol- and gallstone-induced AP (p = 0.03 and 0.01, resp.).

Conclusions

Current smoking, pancreatic necrosis, and bacteremia can aggravate the clinical course of AP. Pancreatic fluid collection and dyslipidemia were associated with AP severity according to the different etiologies. Obesity may also be associated with AP severity in both etiologies.

How does cigarette smoking cause acute pancreatitis?

INTRODUCTION

Acute Pancreatitis (AP) is an emerging health problem world-wide and it is a major cause of admissions for gastrointestinal disease in many countries. Amongst the more common causes (alcohol and gallstones), recent evidence has emerged indicating that smoking is an independent risk factor for AP. However, the mechanisms involved in smoking-induced AP have not been completely elucidated. This review puts together all the published evidence in literature to present the clinical and laboratory evidence relating smoking to the causation of AP.

DISCUSSION

The two main metabolites from cigarette smoke, namely nicotine and NNK are able to induce functional and histological changes within the pancreas consistent with AP. The major mechanisms involved include their action on acinar cells and zymogen secretion through pathways involving CCK and the nicotinic preganglionic receptors. Effects on the pancreatic microvasculature may be mediated through the nitric oxide pathway. There is indirect evidence to suggest that nicotine and acrolein may lead to CFTR dysfunction thereby influencing ductal secretion. However, direct evidence for this effect is needed. The effect of cigarette smoke metabolites on stellate cells and the islets warrants further investigation in the context of pathogenesis of AP.

CONCLUSION

Using a step-wise approach, the review revisits the effects of the various metabolites of cigarette smoke on the constituents of the pancreas (exocrine, endocrine, neurohormonal, stellate cells, ductal system) and highlights their proven, and potential, mechanisms in triggering off an attack of AP.

Maternal Smoking Dysregulates Protein Expression in Second Trimester Human Fetal Livers in a Sex-Specific Manner

CONTEXT

Maternal smoking during pregnancy has adverse effects on the offspring (eg, increased likelihood of metabolic syndrome and infertility), which may involve alterations in fetal liver function.

OBJECTIVE

Our aim was to analyze, for the first time, the human fetal liver proteome to identify pathways affected by maternal smoking.

DESIGN

Fetal liver proteins extracted from elective second trimester pregnancy terminations (12-16 weeks of gestation) were divided in four balanced groups based on sex and maternal smoking.

SETTING AND PARTICIPANTS

Livers were collected from 24 morphologically normal fetuses undergoing termination for nonmedical reasons and analyzed at the Universities of Aberdeen and Glasgow.

MAIN OUTCOME MEASURES

Protein extracts were resolved by 2D-PAGE and analyzed with SameSpots software. Ingenuity pathway analysis was used to investigate likely roles of dysregulated proteins identified by tandem liquid chromatography/mass spectroscopy.

RESULTS

Significant expression differences between one or more groups (fetal sex and/or maternal smoking) were found in 22 protein spots. Maternal smoking affected proteins with roles in post-translational protein processing and secretion (ERP29, PDIA3), stress responses and detoxification (HSP90AA1, HSBP1, ALDH7A1, CAT), and homeostasis (FTL1, ECHS1, GLUD1, AFP, SDHA). Although proteins involved in necrosis and cancer development were affected in both sexes, pathways affecting cellular homeostasis, inflammation, proliferation, and apoptosis were affected in males and pathways affecting glucose metabolism were affected in females.

CONCLUSIONS

The fetal liver exhibits marked sex differences at the protein level, and these are disturbed by maternal smoking. The foundations for smoke-induced post-natal diseases are likely to be due to sex-specific effects on diverse pathways.

Meta-analysis: Tobacco smoking may enhance the risk of acute pancreatitis

BACKGROUND AND AIM

Questions remain unclear about the association of smoking status and the development of acute pancreatitis (AP). We performed a meta-analysis of observational studies explore this association.

METHODS

A computerized literature search was performed in MEDLINE and EMBASE through November 30, 2014. We also searched the reference lists of pertinent articles. We used a random-effects model to calculate the summary relative risks (SRRs) and their corresponding 95% confidence intervals (CIs).

RESULTS

A total of 3690 incident cases of AP included 12 observational studies (6 case-control and 6 prospective cohort/nested case-control studies) were identified. Compared with never smokers, the summary RR estimates were 1.54 (95% CI, 1.31-1.80) for ever smokers, 1.71 (95% CI, 1.37-2.14) for current smokers, and 1.21 (95% CI, 1.02-1.43) for former smokers. Smoking is found to be a potential risk factor for alcohol use, idiopathic factors and drugs related AP, but not for gallstone related AP, in the ever and current smokers. A dose-response effect of tobacco use on the risk was ascertained: current smokers had a 40% (95% CI, 30%-51%) increased risk of AP for every additional 10 cigarettes per day.

CONCLUSION

The present analysis suggests that smokers have an elevated risk of AP development. Further studies, however, are warranted before definitive conclusions can be drawn.

Axonal guidance signaling pathway interacting with smoking in modifying the risk of pancreatic cancer: a gene- and pathway-based interaction analysis of GWAS data

Cigarette smoking is the best established modifiable risk factor for pancreatic cancer. Genetic factors that underlie smoking-related pancreatic cancer have previously not been examined at the genome-wide level. Taking advantage of the existing Genome-wide association study (GWAS) genotype and risk factor data from the Pancreatic Cancer Case Control Consortium, we conducted a discovery study in 2028 cases and 2109 controls to examine gene-smoking interactions at pathway/gene/single nucleotide polymorphism (SNP) level. Using the likelihood ratio test nested in logistic regression models and ingenuity pathway analysis (IPA), we examined 172 KEGG (Kyoto Encyclopedia of Genes and Genomes) pathways, 3 manually curated gene sets, 3 nicotine dependency gene ontology pathways, 17 912 genes and 468 114 SNPs. None of the individual pathway/gene/SNP showed significant interaction with smoking after adjusting for multiple comparisons. Six KEGG pathways showed nominal interactions (P < 0.05) with smoking, and the top two are the pancreatic secretion and salivary secretion pathways (major contributing genes: RAB8A, PLCB and CTRB1). Nine genes, i.e. ZBED2, EXO1, PSG2, SLC36A1, CLSTN1, MTHFSD, FAT2, IL10RB and ATXN2 had P interaction < 0.0005. Five intergenic region SNPs and two SNPs of the EVC and KCNIP4 genes had P interaction < 0.00003. In IPA analysis of genes with nominal interactions with smoking, axonal guidance signaling $$\left(P=2.12\times 1{0}^{-7}\right)$$ and α-adrenergic signaling $$\left(P=2.52\times 1{0}^{-5}\right)$$ genes were significantly overrepresented canonical pathways. Genes contributing to the axon guidance signaling pathway included the SLIT/ROBO signaling genes that were frequently altered in pancreatic cancer. These observations need to be confirmed in additional data set. Once confirmed, it will open a new avenue to unveiling the etiology of smoking-associated pancreatic cancer.

The pathobiological impact of cigarette smoke on pancreatic cancer development (review)

Despite extensive efforts, pancreatic cancer remains incurable. Most risk factors, such as genetic disposition, metabolic diseases or chronic pancreatitis cannot be influenced. By contrast, cigarette smoking, an important risk factor for pancreatic cancer, can be controlled. Despite the epidemiological evidence of the detrimental effects of cigarette smoking with regard to pancreatic cancer development and its unique property of being influenceable, our understanding of cigarette smoke-induced pancreatic carcinogenesis is limited. Current data on cigarette smoke-induced pancreatic carcinogenesis indicate multifactorial events that are triggered by nicotine, which is the major pharmacologically active constituent of tobacco smoke. In addition to nicotine, a vast number of carcinogens have the potential to reach the pancreatic gland, where they are metabolized, in some instances to even more toxic compounds. These metabolic events are not restricted to pancreatic ductal cells. Several studies show that acinar cells are also greatly affected. Furthermore, pancreatic cancer progenitor cells do not only derive from the ductal epithelial lineage, but also from acinar cells. This sheds new light on cigarette smoke-induced acinar cell damage. On this background, our objective is to outline a multifactorial model of tobacco smoke-induced pancreatic carcinogenesis.

Long-term nicotine exposure causes increased concentrations of trypsinogens and amylase in pancreatic extracts in the rat

To develop radioimmunoassays (RIAs) for rat trypsinogens 1 and 2 and to investigate the effect of nicotine exposure on concentration and production of pancreatic zymogens in the rat.

METHODS

Male Sprague-Dawley rats were supplied with either normal or nicotine-containing (0.77 mM) water for 28 days and were then killed. Rabbit antibodies for the activation peptides of trypsinogens 1 and 2 were obtained for use in the RIAs. Concentrations of the both trypsinogens in pancreatic extracts were measured by the RIAs after activation by enterokinase. DNA and amylase were measured using commercial kits. mRNA for trypsinogens 1 and 2, procolipase, and cholecystokinin receptor was measured by in situ hybridization.

RESULTS

The specificity of the RIA for the trypsinogen 1 activation peptide was satisfactory. The RIA for the trypsinogen 2 activation peptide showed a limited cross-reaction toward the synthetic trypsinogen 1 activation peptide, but the importance of this cross-reaction was moderate when investigated in samples of activated trypsinogens. Weight gain was reduced in nicotine-treated animals. Concentrations of amylase, trypsinogen 1, trypsinogen 2, and the ratio of trypsinogen 2 to 1 were all increased in pancreatic extracts of nicotine-fed animals. Total DNA and mRNA for the trypsinogens, procolipase, and cholecystokinin receptor were not affected by nicotine exposure.

CONCLUSIONS

The combination of increased proenzyme concentrations and unaffected mRNA levels suggests that nicotine impairs secretion rather than production of pancreatic zymogens.

A prospective cohort study of smoking in acute pancreatitis

BACKGROUND/AIMS

Little is known about risk factors for acute pancreatitis other than gallstones and alcohol consumption. The aim of this study was to investigate if smoking or body mass index (BMI) are associated with acute pancreatitis and to determine relative risks (RR) for acute pancreatitis related to smoking, BMI, and alcohol consumption.

METHODS

From 1974 to 1992, selected birth-year cohorts of residents in Malmo, Sweden (born 1921-1949) were invited to a health-screening investigation including physical examination, blood sampling and a questionnaire. In total, 33,346 individuals participated. Cases of acute pancreatitis were identified from diagnosis registries (n = 179). Incidence rates were calculated in different risk factor categories. A Cox's analysis revealed RR.

RESULTS

Current versus never smoking at baseline was associated with acute pancreatitis (RR 2.14, 95% confidence interval (CI) 1.48-3.09) after adjustment for age, sex, BMI and alcohol consumption. This association was stronger in heavy smokers (20-30 cigarettes/day) (RR 3.19, 95% CI 2.03-5.00). Smoking was associated with a RR of 3.57 (95% CI 0.98-13.0) for acute pancreatitis in subjects who reported no alcohol consumption. An increased risk for acute pancreatitis was also found for high versus low risk, self-reported alcohol consumption (RR 2.55, 95% CI 1.59-4.08) and for gamma-GT levels in the highest versus the lowest quartile (RR 2.14, 95% CI 1.32-3.49). There was also a weak correlation between BMI and acute pancreatitis.

CONCLUSIONS

Smoking is associated with the incidence of acute pancreatitis in a dose-response manner. and IAP.

Smoking cessation at the clinical onset of chronic pancreatitis and risk of pancreatic calcifications

OBJECTIVE

Cigarette smoking is associated with a higher risk of developing chronic pancreatitis (CP) and increases the likelihood of developing pancreatic calcifications. The aim of this study was to know whether smoking cessation modifies the course of the disease.

METHODS

Patients with CP who had been followed up for more than 6 years from clinical onset and who had not developed calcifications after 5 years were analyzed. We studied smokers, never-smokers, and patients who had given up smoking within 5 years. For actuarial analysis, the sixth year was considered as time 0.

RESULTS

Of the 360 patients, there were 43 women and 317 men (88.1%) with a mean age of 38.7 years. The median follow-up was 19.0 years. Chronic pancreatitis was alcohol-associated in 255 patients, hereditary in 10, obstructive in 54, and idiopathic in 41. There were 317 smokers (88.1%) and 259 alcohol drinkers (71.9%). At the end of the follow-up, 212 patients (59.8%) developed calcifications. Concerning the risk of calcifications, never-smokers and ex-smokers had similar actuarial curves, and these were significantly different from the curve for smokers (P < 0.003). Considering never-smokers as the reference class, ex-smokers had an odds ratio (OR) of 0.56 (95.0% confidence interval [CI], 0.2-1.4; P = not significant), patients smoking 1 to 10 cigarettes per day had an OR of 1.95 (95.0% CI, 1.1-3.4; P < 0.019), patients smoking 11 to 20 cigarettes per day had an OR of 1.76 (95.0% CI, 1.1-2.8; P < 0.0018), and those smoking more than 20 cigarettes per day had an OR of 1.79 (95.0% CI, 1.1-2.9; P < 0.019). Alcohol cessation seems to have no influence.

CONCLUSIONS

Smoking cessation in the first years from the clinical onset of CP reduces the risk of developing pancreatic calcifications.

Dysfunction of the pancreas in healthy smoking persons and patients with chronic pancreatitis

OBJECTIVES

The aim of the study was to assess the effect of cigarette smoking on the endocrine pancreatic function by determining the levels of serum glucose and plasma insulin as well as by defining immunohistochemical localization of insulin and glucagon in tissue specimens of the pancreata derived from healthy persons and smoking and nonsmoking patients with diagnosed chronic pancreatitis (CP).

METHODS

The oxidative method was used to measure fasting glycemia in blood plasma and the method enzyme-linked immunoassay to determine the level of insulin in plasma. Immunohistochemical localization of hormones in paraffin tissue specimens of the pancreas was performed using the LSAB2-HRP visual test with polyclonal insulin and glucagon antibodies. The intensity of immunohistochemical reaction was calculated with digital imaging methodology.

RESULTS

The study revealed a substantially higher level of serum glucose in smoking CP patients and in healthy persons compared with nonsmoking patients and healthy persons, whereas insulin concentration in smoking patients was statistically lower than in nonsmokers. Smoking patients showed significantly lower expression of insulin and glucagon in the pancreas compared with nonsmoking patients and healthy persons.

CONCLUSIONS

Impairment of the endocrine function of beta and alpha cells in the pancreatic islets is frequently manifested by complications in pancreatitis resulting among others from long-term smoking.

Smoking, coffee, and pancreatitis

OBJECTIVES

We studied relationships of cigarette smoking and coffee drinking to risk of pancreatitis.

METHODS

This was a cohort study among 129,000 prepaid health plan members who supplied data about demographics and habits in 1978-85. Among 439 persons subsequently hospitalized for pancreatitis, probable etiologic associations were cholelithiasis (168/439 = 38%), alcohol (125/439 = 29%), idiopathic (110/430 = 25%), and miscellaneous (36/439 = 8%). Cox proportional hazards models with seven covariates (including alcohol intake) yielded relative risk estimates for smoking and coffee use.

RESULTS

Increasing smoking was strongly related to increased risk of alcohol-associated pancreatitis, less related to idiopathic pancreatitis, and unrelated to gallstone-associated pancreatitis. Relative risks (95% confidence intervals, CI) of one pack per day (vs never) smokers for pancreatitis groups were: alcohol = 4.9 (2.2-11.2, p < 0.001), idiopathic = 3.1 (1.4-7.2, p < 0.01), and gallstone = 1.3 (0.6-3.1). The relationship of smoking to alcohol-associated pancreatitis was consistent in sex and race subsets. Drinking coffee, but not tea, was weakly inversely related to risk only of alcohol-associated pancreatitis, with relative risk (95% CI) per cup per day = 0.85 (0.77-0.95; p= 0.003). Male sex, black ethnicity, and lower-educational attainment were other predictors of alcohol-associated pancreatitis.

CONCLUSIONS

Cigarette smoking is an independent risk factor for alcohol-associated and idiopathic pancreatitis. Coffee drinking is associated with reduced risk of alcohol-associated pancreatitis. The data are compatible with the hypotheses that smoking may be toxic to the pancreas or may potentiate other pancreatic toxins while some ingredient in coffee may have a modulating effect.

Cigarette smoking increases the risk of pancreatic calcification in late-onset but not early-onset idiopathic chronic pancreatitis

An association exists between cigarette smoking and pancreatitis owing to alcohol. We determined whether cigarette smoking affected the course of pancreatic calcification and insufficiency in idiopathic chronic pancreatitis. Medical records were analyzed of 24 persons with early- and 42 with late-onset idiopathic chronic pancreatitis who were diagnosed between 1976 and 1982 and then followed prospectively until 1985. Smoking equaled >5 pack-years before calcification or insufficiency or last follow-up. Mean follow-up after onset of chronic pancreatitis was 27 and 13 years in early- and late-onset idiopathic chronic pancreatitis, respectively. Incidence of calcification in the two groups was 58 and 43%, respectively. In early-onset idiopathic chronic pancreatitis, smokers and nonsmokers developed calcification at a similar rate and frequency (58%). In late-onset idiopathic chronic pancreatitis, smokers developed pancreatic calcifications faster (p < 0.001) and more frequently (83 vs. 13%, p < 0.001) than nonsmokers. The association between smoking and pancreatic calcification was independent of gender, body mass index, and exocrine or endocrine insufficiency. Smoking did not affect development of exocrine or endocrine insufficiency. Cigarette smoking increases the risk of pancreatic calcification of late- but not of early-onset idiopathic chronic pancreatitis. These data support encouraging cessation of smoking in chronic pancreatitis.

Life-time history of smoking and exocrine carcinoma of the pancreas: a population-based case-control study in The Netherlands

From 1984 to 1988 a population-based case-control study was carried out in the Netherlands in collaboration with the International Agency for Research on Cancer, to examine the possible relationship between habitual, life-time consumption of varieties of tobacco and exocrine pancreatic carcinoma in 176 cases and 487 controls. An interviewer-administered questionnaire was used to list major life events and obtain estimates of usual frequency of tobacco consumption throughout life. About 58% of patients were interviewed directly. After adjustment for age, gender, response status, energy intake and consumption of vegetables compared with never-smokers, a positive dose-response effect of smoking of life-time number of total cigarettes, i.e. non-filter and filter, emerged (OR 1.00, 1.35, 1.40 and 2.10, p-value trend less than 0.05). Results of simultaneous estimation of the effects of life-time smoking of non-filter and filter cigarettes suggest that the effect was present primarily in non-filter cigarettes. The dose-response relationship was present in current smokers only. Compared with never-smokers, the risk pattern among relatively recent quitters, i.e. 2 to 14 years previously, still suggested a positive effect of past smoking (OR for low smokers 1.99, 95% CI 0.79-4.99 and for high smokers 1.69, 95% CI 0.63-4.58). The risk of quitting 15 years or more could be examined in the low smoking group only and was no different from those who had never smoked (OR 1.02, 95% CI 0.47-2.20). In brief, our results suggest that, independent of usual past intake of energy and vegetables, life-time smoking of cigarettes influences the development of exocrine pancreatic cancer, whereas cessation of smoking of cigarettes for 15 years or more reduces the risk to the levels found among those who have never smoked.

Dynamic changes of pancreatic structure and function in rats treated chronically with nicotine

Adult, male Sprague-Dawley rats weighing initially 185-225 g, were treated with 5, 15, or 50 mg nicotine or placebo 3-week-release pellets by sc implantation, for 1.5, 3, 6 and 12 weeks. These doses of nicotine correspond to infusion rates of 9.9, 29.8, and 99.2 micrograms/h, respectively. At the highest nicotine dose trypsin and chymotrypsin activities were markedly higher in pancreas from 12-week nicotine-treated rats compared with controls. This was associated with a fourfold increase in steady-state amylase mRNA levels in comparison to placebo controls. In addition, secretagogue-stimulated enzyme release from pancreatic acini isolated from rats treated with 50 mg nicotine pellets was significantly higher than controls at 1.5 and 3 weeks and declined below control levels after 12 weeks of treatment. In rats treated with 15-mg nicotine pellets, maximal secretagogue-stimulated enzyme release from isolated acini occurred at 1.5 weeks, declining thereafter to control levels. Electron microscopy of pancreas from rats treated with the 50 mg nicotine dose revealed intracytoplasmic vaculoes appearing after 3 weeks of treatment, and persisting throughout the remaining experimental period. It is concluded that 12-week nicotine treatment results in increased pancreatic enzyme biosynthesis and accumulation of digestive enzymes within the pancreas. This is associated with altered responsiveness to secretagogues and evidence of morphological damage.

Altered exocrine pancreatic function in rats treated with nicotine

The present study investigates the effects of nicotine treatment on exocrine pancreatic function. Adult male, Sprague-Dawley rats received nicotine via a time-release pellet, at a rate of 1.65 micrograms/min for 3 weeks. At the end of the experimental period, it was observed that although nicotine did not affect final body or pancreatic weight, the activities of amylase, trypsin, and chymotrypsin in pancreatic homogenates from nicotine-treated rats were 51, 29, and 35% higher, respectively, than in controls. Levels of immunoreactive cationic trypsin(ogen) were significantly higher in pancreatic homogenates and serum from nicotine-treated rats as compared with controls. In addition, concentrations of mRNA, encoding for pancreatic amylase, were higher in pancreatic homogenates from the nicotine-treated rats than in controls. In dispersed pancreatic acini isolated from nicotine-treated rats, basal secretion of amylase, trypsinogen, and chymotrypsinogen was 50% higher than controls and enzyme release following CCK-8 (100 pM), secretin (1 microM), and carbachol (7.5 microM) stimulation was also significantly higher. These data indicate that nicotine treatment, at levels comparable to those expected in moderate cigarette smokers, increases the content of digestive enzymes in rat pancreas, as well as their basal and secretagogue-induced release.

Serum elastase 1 in inflammatory pancreatic and gastrointestinal diseases and in renal insufficiency. A comparison with other serum pancreatic enzymes

Serum elastase 1 has been evaluated in 115 patients with pancreatic and nonpancreatic gastrointestinal diseases and in 36 healthy controls. Increased serum elastase 1 values were found in all 27 patients with acute pancreatitis. If the diagnostic cutoff was established as the 2-fold increase above the upper normal range, sensitivity of elastase 1 (100%) was superior to pancreatic lipase (90%), immunoreactive trypsin (87%) and pancreatic amylase (78%). Specificity was 96% for elastase 1 at this cutoff. No distinction was possible between edematous and necrotizing acute pancreatitis on the basis of peak serum elastase 1 concentrations. Among 32 patients with chronic pancreatitis increased serum elastase 1 values were found in 22% and decreased values in 16% of patients, showing a striking parallelism to serum values of pancreatic lipase and immunoreactive trypsin. Specificity, established in controls and 49 patients with different gastrointestinal diseases, was 77% for elastase 1, 76% for immunoreactive trypsin, 83% for pancreatic lipase and 91% for pancreatic amylase. In addition, we investigated 21 patients with severe chronic renal diseases. In patients with renal insufficiency elastase was increased in 33%, comparable to the frequency of increased amylase and pancreatic amylase serum levels, whereas immunoreactive trypsin was increased in 95%. Immunoreactive trypsin showed a significant correlation to creatinin serum concentration, whereas the other enzymes did not.

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.

Effect of secretin upon the levels of pancreatic enzymes in blood serum

We have evaluated the serum changes of trypsin, pancreatic isoamylase and lipase, after rapid infusion of secretin, in 45 patients with chronic pancreatitis compared with 35 healthy control subjects. On the basis of duodenal intubation results, chronic pancreatitis patients were divided into two subgroups at different levels of functional impairment. Using the peak activities of the enzymes we have been able to separate the two chronic pancreatitis subgroups by statistical difference; only trypsin distinguishes healthy control subjects from mild to moderate chronic pancreatitis. Therefore, we propose to put into clinical practice this serum provocative test to evaluate the functional damage of an established chronic pancreatitis.

[Clinical relevance of immunochemical determination of pancreatic lipase in chronic pancreatitis]

The determination of basal pancreatic serum enzymes is of little value in the diagnosis of chronic pancreatitis. The organ specificity of a recently introduced immunochemical method of determining pancreatic lipase is guaranteed. The diagnostic value of the basal and stimulated serum-lipase determination by the immunochemical assay in chronic pancreatitis was investigated on 84 patients and controls. In 46 patients with chronic pancreatitis the serum increase of pancreatic lipase after secretin stimulation (1 U/kg) was significantly (P less than 0.01) higher than the pancreatic lipase increase in patients with non-pancreatic intestinal disorders and in healthy controls. Patients with chronic pancreatitis deserve to be classified in subgroups, according to the degree of the exocrine pancreatic insufficiency established by means of the secretin-ceruletide test. Of the patients with chronic pancreatitis and a slight to moderate exocrine pancreatic insufficiency 87% show an abnormal serum pancreatic-lipase increase and differ significantly (P less than 0.01) from patients with severe exocrine insufficiency who exhibit an increase of the pancreatic serum lipase only in exceptional cases. Specificity is limited, since an abnormal serum lipase increase after stimulation is found in 20% of controls.

Ethanol and the pancreas

The acute and chronic effects of ethanol on pancreatic structure and function are discussed. Acute necrotizing, acute edematous, acute relapsing, chronic relapsing, and painless pancreatitis have an established association with ethanol abuse. The management of these disorders is outlined.

A radioimmunoassay for rat pancreatic secretory trypsin inhibitor

A radioimmunoassay for the detection of pancreatic secretory trypsin inhibitor (PSTI) in the rat is described. The sensitivity of the assay enables the specific measurement of this inhibitor in the serum of normal rats. The average base-line value for multiple animal serum specimens taken from fasting female Wistar rats being fed conventional diets was 11.6 +/- 6.2 micrograms/l. The inhibitor existed in its free form in serum, and PSTI immunoreactivity increased significantly within 2 h of the induction of experimental pancreatitis. The present assay will facilitate the study of PSTI in experimental diseases of the pancreas.