Chronic pancreatitis

An increasing number of novel mutations are associated with chronic pancreatitis. Some cause a high-penetrance, autosomal dominant type of clinical picture (eg, mutations at codons 29 and 122 of the cationic trypsinogen gene), whereas others have a low penetrance or are frequent in the general population (eg, mutations in Kazal type 1 [SPINK1] and in codons 16, 22, and 23 of the cationic trypsinogen gene) and act as disease modifiers. The results of recent studies indicate that smoking adversely affects the course and complications of chronic pancreatitis (more frequent and faster rate of calcification and higher risk of development of pancreatic cancer). Thus, regardless of the cause of chronic pancreatis, patients with this condition should not smoke. Using current diagnostic criteria, the accuracy of endoscopic ultrasound for the diagnosis of chronic pancreatitis is not good. For example, 39% of dyspeptic persons without any other evidence of chronic pancreatitis fulfilled the endoscopic ultrasound criteria for chronic pancreatitis. Diabetes frequently occurs in chronic pancreatitis, but it is not prevented or increased by pancreatic surgery. Islet cell autotransplantation holds promise for the prevention of diabetes in patients requiring total pancreatectomy if the pancreas is not extensively fibrotic. Splenic vein occlusion is present in 7% of patients undergoing surgery for chronic pancreatitis, but fewer than one fifth of these patients have variceal bleeding before or after surgery.

Islet amyloid polypeptide is not a satisfactory marker for detecting pancreatic cancer

BACKGROUND & AIMS

Islet amyloid polypeptide (IAPP) levels are elevated in pancreatic cancer and may be a useful marker of pancreatic cancer-associated diabetes. The aim of this study was to compare the sensitivity and specificity for pancreatic cancer of IAPP with that of CA19-9, examine clinical characteristics of diabetes in pancreatic cancer, and define the relationship of IAPP to diabetes of pancreatic cancer.

METHODS

Fasting serum glucose, IAPP, and CA 19-9 were measured in 130 subjects with pancreatic cancer, 250 subjects with other pancreatic and peripancreatic diseases, and 116 controls. In pancreatic cancer patients, we noted tumor stage and the presence and duration of diabetes.

RESULTS

IAPP was markedly elevated in pancreatic cancer, especially in patients with diabetes. However, the sensitivity of IAPP for pancreatic cancer was less than that of CA 19-9 (40% vs. 75%; P < 0.001). Diabetes was present in 46% of pancreatic cancers and 55% of resectable tumors. In pancreatic cancer with diabetes, the sensitivity of IAPP was only 50%. In resectable cancer it was 27%.

CONCLUSIONS

IAPP is elevated in pancreatic cancer but is not sensitive enough to replace or complement existing tests. Diabetes occurs early and frequently in pancreatic cancer. Development of a sensitive and specific marker for pancreatic-associated diabetes might lead to diagnosis of resectable pancreatic cancer.

Utility of endoscopic ultrasonography in endoscopic drainage of pancreatic pseudocysts in selected patients

OBJECTIVES

To determine the effect of endoscopic ultrasonography (EUS) on endoscopic drainage of pancreatic pseudocysts and to determine patency with fistula dilation and placement of multiple stents.

PATIENTS AND METHODS

Between September 1995 and January 1999, 19 patients underwent endoscopic drainage of pancreatic pseudocysts, 17 of whom were assessed by EUS before drainage. Radial EUS scanning was used to detect an optimal site of apposition of pseudocyst and gut wall, free of intervening vessels. A fistula was created with a fistulatome, followed by balloon dilation of the fistula tract. Patency was maintained with multiple double pigtail stents. The primary goal of this retrospective study was to determine whether EUS affected the practice of endoscopic drainage of pancreatic pseudocysts.

RESULTS

In 3 patients, drainage was not attempted based on EUS findings. In the other 13 patients (14 pseudocysts), creation of a fistula was successful on 13 occasions, and no immediate complications occurred. However, 1 patient subsequently developed sepsis that required surgery. All other patients were treated with balloon dilation, multiple stents, and antibiotics, with no septic complications. Of 14 pseudocysts (in 13 patients), 13 (93%) resolved.

CONCLUSIONS

Results of EUS may alter management of patients considered for endoscopic drainage of pancreatic pseudocysts. Endoscopic ultrasonography was useful for selecting an optimal and safe drainage site. The combination of balloon dilation, multiple stents, and antibiotics appears to resolve pancreatic pseudocysts without septic complications.

Utility of endoscopic ultrasonography in endoscopic drainage of pancreatic pseudocysts in selected patients

OBJECTIVES

To determine the effect of endoscopic ultrasonography (EUS) on endoscopic drainage of pancreatic pseudocysts and to determine patency with fistula dilation and placement of multiple stents.

PATIENTS AND METHODS

Between September 1995 and January 1999, 19 patients underwent endoscopic drainage of pancreatic pseudocysts, 17 of whom were assessed by EUS before drainage. Radial EUS scanning was used to detect an optimal site of apposition of pseudocyst and gut wall, free of intervening vessels. A fistula was created with a fistulatome, followed by balloon dilation of the fistula tract. Patency was maintained with multiple double pigtail stents. The primary goal of this retrospective study was to determine whether EUS affected the practice of endoscopic drainage of pancreatic pseudocysts.

RESULTS

In 3 patients, drainage was not attempted based on EUS findings. In the other 13 patients (14 pseudocysts), creation of a fistula was successful on 13 occasions, and no immediate complications occurred. However, 1 patient subsequently developed sepsis that required surgery. All other patients were treated with balloon dilation, multiple stents, and antibiotics, with no septic complications. Of 14 pseudocysts (in 13 patients), 13 (93%) resolved.

CONCLUSIONS

Results of EUS may alter management of patients considered for endoscopic drainage of pancreatic pseudocysts. Endoscopic ultrasonography was useful for selecting an optimal and safe drainage site. The combination of balloon dilation, multiple stents, and antibiotics appears to resolve pancreatic pseudocysts without septic complications.

Gastric acid suppression and treatment of severe exocrine pancreatic insufficiency

Adding either H(2)-receptor antagonists (cimetidine or ranitidine) or proton pump inhibitors to an adequate amount of lipolytic activity improves fat malabsorption in most cases and abolishes steatorrhoea in up to 40% of children and adults with cystic fibrosis and in adults with chronic pancreatitis. Acid suppression improves fat absorption because the resultant increase in pH within the upper gastrointestinal tract improves the survival of lipolytic activity, reduces duodenal volume flow and prevents the precipitation of bile acids. These effects increase the concentration of intraduodenal lipolytic activity and promote the aggregation of bile acids and the micellar solubilization of lipid. The amount of lipase that should be recommended is controversial, but we interpret our studies as indicating that at least 90 000 United States Pharmacopeia (USP) units should be ingested with meals. This amount of lipolytic activity taken with an agent that suppresses gastric acid secretion improves fat absorption in most patients and may even abolish steatorrhoea.

Protection of research subjects with emphasis on protocols involving radiation

Approval by an institutional review board (IRB) or human studies committee must be obtained prior to conducting human subject research. Historically this was not the case, and human subjects were injured as a result. Because there has been and still remains an inevitable conflict of interest for researchers, instititions that perform human research must follow regulations designed to protect human subjects contained in the Code of Federal Regulations, if the research is federally funded. Two federal agencies provide oversight for IRB activities: the Food and Drug Administration (FDA) and a National Institutes of Health Office for Human Research Protection (OHRP), formerly the Office for Protection from Research Risks (OPRR). These agencies are charged with the implementation of rules related to ethical and legal obligations of researchers and their institutions. The institution's role, by means of an IRB, is to adhere to principles of the Belmont Report and to set forth ethical principles, policies, and procedures for protecting the rights and welfare of human subjects. The researchers' role is to conduct their research ethically while maximizing benefits and minimizing harm. Studies involving radiation exposure of human subjects add another level of risk that must be evaluated by an IRB with assistance of a radiation expert or radiation safety committee (RSC). This paper will look at regulatory aspects of human research, IRB responsibilities overall and as they relate to radiation exposure of subjects, and the role of the RSC.

The effect of small amounts of alcohol on the clinical course of chronic pancreatitis

OBJECTIVE

To investigate the hypothesis that an increasing intake of alcohol accelerates the course of chronic pancreatitis.

PATIENTS AND METHODS

In this retrospective record analysis and subsequent prospective follow-up of 372 patients with chronic pancreatitis, we separately compared the clinical course of chronic pancreatitis among the following patients: those with early-onset idiopathic chronic pancreatitis and no alcohol intake (group A [n=25]) and those with late-onset idiopathic chronic pancreatitis and no alcohol intake (group B [n=41]), low alcohol intake (< 50 g/d) (group C [n=57]), and high alcohol intake (> or = 50 g/d) (group D [n=249]). From medical records, physical examinations, questionnaires, death certificates, or autopsy reports, we obtained information on sex, age, signs and symptoms (pain severity, calcification, endocrine and exocrine insufficiency), complications, surgery, and survival.

RESULTS

Group D had the highest percentage of men (72%). At the onset of chronic pancreatitis, patients in group A were significantly younger than those in groups B, C, and D (P<.05), and severity of pain was significantly greater in patients in group A than in groups B, C, and D (P<.05). The percentage of patients who eventually developed endocrine or exocrine insufficiency was similar in all groups. Among patients in groups B, C, and D, an increasing intake of alcohol from zero to less than 50 g/d to more than 50 g/d was associated with earlier inception of disease (P<.001). Pain prevalence at onset was less in group B patients than in patients in groups C and D (P<.05). Intake of a large amount of alcohol (group D) shortened time to calcification and survival (P<.05). In addition, patients in group D had more complications (fistulas, pseudocysts, abscesses, and biliary obstruction) (P<.05) than those in groups A and B. More patients in group A underwent pancreatic surgery compared with patients in groups B and C.

CONCLUSIONS

Among patients with onset of chronic pancreatitis after age 35 years, alcohol intake, even less than 50 g/d, induced earlier disease characterized by more frequent severe pain, calcification, and complications. Intake of large amounts of alcohol (> or = 50 g/d) reduced time to calcification and death.

Chronic pancreatitis

In the past year, there has been at least one important clinical paper that sheds light on the character and natural history of painful chronic pancreatitis, which has important clinical implications. In addition, several novel mutations have been described in the cationic trypsinogen gene in patients with hereditary pancreatitis. The mechanism by which these mutations cause pancreatic disease remains speculative. The diagnosis of early chronic pancreatitis is controversial. A novel noninvasive pancreatic function test (measurement of postprandial APOB-48) was reported but is unlikely to be a sensitive test of pancreatic function. Pancreatic fibrosis is frequently seen in alcoholics without chronic pancreatitis, and this makes it difficult to interpret the findings on endoscopic ultrasonogram. Recent studies highlight the difficulty in abolishing pancreatic steatorrhea. Recently fibrosing colonopathy in adult patients has been reported. Extracorporeal shockwave lithotripsy combined with endoscopic therapy failed to benefit patients with calcific chronic pancreatitis.

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.

Acute pancreatitis in the postpartum period: a population-based case-control study

OBJECTIVE

To determine relationships among pregnancy (during and postpartum), acute pancreatitis, and gallstones.

PATIENTS AND METHODS

In this retrospective population-based case-control study, we identified all 12- to 50-year-old Rochester, Minn, females diagnosed between 1976 and 1991 as having acute pancreatitis (cases). For each case, we matched 4 women of the same age (+/- 6 years) with no history of acute pancreatitis (controls). Acute pancreatitis was defined as associated with pregnancy if it occurred from 10 months prior to delivery to delivery and with the postpartum period if it occurred within 10 months of the date of delivery. Logistic regression was used to assess associations between pregnancy-related acute pancreatitis, age, gallstone occurrence, and alcohol use.

RESULTS

In a cohort of 61 women who developed acute pancreatitis and 244 controls, the relative risk for acute pancreatitis associated with pregnancy was 1.43 (95% confidence interval, 0.61-3.40). All 10 cases of acute pancreatitis associated with pregnancy occurred in the postpartum period. Gallstones were present in 6 of them compared with 13 of 51 women with non-pregnancy-related acute pancreatitis (P < .05). Women with postpartum-related pancreatitis were younger than those with non-pregnancy-related pancreatitis (mean, 28 vs 36 years; P < .05). Alcohol was not associated with pregnancy-related pancreatitis.

CONCLUSIONS

Acute pancreatitis during the postpartum period is not directly related to pregnancy but is associated with gallstones and occurs in younger women.

Clinical and pathologic correlation of 84 mucinous cystic neoplasms of the pancreas: can one reliably differentiate benign from malignant (or premalignant) neoplasms?

OBJECTIVE

To determine whether the long-term behavior of cystic mucinous neoplasms of the pancreas could be predicted using a novel, precisely defined classification of benign mucinous cystadenomas, noninvasive proliferative cystic mucinous neoplasms, and invasive mucinous cystadenocarcinomas. The primary interest was to obtain long-term follow-up after complete resection to determine the recurrence rates based on this objective classification.

BACKGROUND

Current understanding is that all cystic mucinous neoplasms of the pancreas are potentially malignant and that mucinous cystadenomas, when completely removed, are biologically benign. Cystadenocarcinomas are thought to be less aggressively malignant than ordinary ductal adenocarcinoma, but reported recurrence rates vary widely and are unpredictable.

METHODS

All patients who underwent "curative" resection for cystic mucinous neoplasms at Mayo Clinic Rochester from 1940 to 1997 were identified. All available pathology slides, gross specimens, and clinical records were reviewed, eliminating patients with inadequate documentation. Neoplasms were reclassified as mucinous cystadenomas, noninvasive proliferative mucinous cystic neoplasms, or invasive cystadenocarcinomas based on specific histologic criteria.

RESULTS

Of 84 patients (70 women, 14 men) with cystic mucinous neoplasms of the pancreas, 54 were classified as cystadenomas, 23 as noninvasive proliferative cystic mucinous neoplasms, and only 7 as cystadenocarcinomas. Recurrent disease developed in none of the 77 patients without invasion, but 5 of the 6 patients surviving resection for cystadenocarcinomas died of recurrent cystadenocarcinoma within 5 years.

CONCLUSIONS

When the neoplasm is completely resected and subjected to adequate histopathologic examination based on these objective criteria, absence of tissue invasion predicts a curative operation and detailed follow-up may be unnecessary. In contrast, a histologic diagnosis of invasive cystadenocarcinoma portends a dismal prognosis, similar to that of typical ductal adenocarcinoma of the pancreas.

AGA technical review on the epidemiology, diagnosis, and treatment of pancreatic ductal adenocarcinoma. American Gastroenterological Association

This literature review and the recommendations therein were prepared for the American Gastroenterological Association Clinical Practice and Practice Economics Committee. The paper was approved by the Committee in March 1999 and by the AGA Governing Board in May 1999.

Pancreatic cancer: clinical presentation, pitfalls and early clues

The diagnosis of pancreatic cancer usually depends upon symptoms; consequently it is late when there is no chance for cure. At this point, pain, anorexia, early satiety, sleep problems and weight loss are present. Back pain also may be prominent, which predicts unresectability and shortened survival after resection. However, earlier recognition of symptoms of pancreatic cancer might improve early detection of the cancer. For example, 25% of patients have symptoms compatible with upper abdominal disease up to 6 months prior to diagnosis and 15% of patients may seek medical attention more than 6 months prior to diagnosis. These symptoms erroneously may be attributed to problems such as irritable syndrome. Symptoms, however, may be less common. For example a quarter of patients with pancreatic cancer may have no pain at diagnosis, and half, particularly those with pancreatic head tumors, may have little pain compared with patients with body-tail tumors. However, if the tumor is suspected because of predisposing conditions, earlier diagnosis may be possible. These conditions include diseases such as chronic pancreatitis, intraductal papillary mucinous tumor (IPMT), and recent onset of diabetes mellitus, particularly if the diabetes occurs during or beyond the sixth decade. In addition inherited syndromes also are associated with an increased risk of pancreatic cancer including familial pancreatic cancer, hereditary pancreatitis, familial adenomatous polyposis syndrome (FAP) and familial atypical multiple mole melanoma (FAMMM) syndrome (hereditary dysplastic nevus syndrome). Of these conditions, recent onset of diabetes may be the best clue and should be included in a clinical profile of patients prior to the onset of symptoms to identify a high-risk group to apply screening strategies for detection of early disease. Contrary to a clinical aphorism that pancreatic cancer patients are elderly, lean and recently may have developed diabetes, we found that patients who develop pancreatic cancer are overweight prior to onset of symptoms compared to controls (body mass index, 28 vs 25). Forty percent had the diagnosis of diabetes made at the time of diagnosis of pancreatic cancer and more patients with a resectable tumor had diabetes (58%) compared to patients with locally unresectable or metastatic disease (37%). Perhaps, screening overweight persons who have new-onset diabetes may lead to a diagnosis of asymptomatic, early, resectable pancreatic cancer.

Early and late onset in idiopathic and alcoholic chronic pancreatitis. Different clinical courses

In summary, a prerequisite for the development of alcoholic pancreatitis would be the specific individual predisposition present in patients with late-onset idiopathic chronic pancreatitis. Furthermore, because the reported prevalence of chronic pancreatitis in patients with heavy alcohol consumption is markedly higher than the prevalence of late-onset idiopathic pancreatitis in the general population, the authors conclude that, in predisposed patients, alcohol consumption promotes the development of pancreatitis and accelerates the manifestation of symptoms and complications. This concept explains the observation that only a minority of severe alcoholics develop chronic pancreatitis. Conversely, in postmortem studies, a substantial proportion of older individuals without premortem evidence of pancreatic disease and no excessive alcohol history have pancreatic morphologic alterations resembling chronic pancreatitis. Thus, in the general population, a considerable number of asymptomatic "carriers," together with an undetected high prevalence of late-onset idiopathic chronic pancreatitis, may exist. In these persons, alcohol consumption might amplify and accelerate preexisting asymptomatic idiopathic pancreatic damage. As a consequence, in a dose-dependent manner, alcohol may lead to an earlier onset of or induce clinically apparent pancreatitis in persons who otherwise might never have had symptoms during their lives.

Acute postprandial gastrointestinal and metabolic effects of wheat amylase inhibitor (WAI) in normal, obese, and diabetic humans

Amylase inhibition has gastrointestinal and metabolic effects that may aid in the treatment of diabetes and obesity. We tested whether 4 g of a commercially available wheat amylase inhibitor (WAI) affected postprandial carbohydrate (CHO) absorption and plasma glucose or hormones. Twelve persons (four lean and four obese nondiabetics and four obese type II diabetics) were studied on 2 separate days. After eating a weight maintenance diet (55% CHO, 20% protein, and 25% fat, as percentage of calories) for 3 days, subjects ate a breakfast containing 650 kcal, the same proportion of nutrients as calories, and in random order, either WAI or no WAI. Breath H2 and plasma glucose and hormones were measured every 15 and 30 min, respectively, for 7 h. WAI decreased the delta peak postprandial plasma glucose concentrations in 10 of 12 subjects (p < 0.05) and increased the breath H2 levels in 11 (p = 0.02); the increases in breath H2 were small, generally <20 ppm. No subject experienced a change in stools, diarrhea, or bloating. In response to WAI, gastric inhibitory peptide decreased (p < 0.05), peptide YY increased (p < 0.05), and there was a trend toward increased human pancreatic polypeptide (p = 0.07). Although WAI delays CHO absorption and reduces peak postprandial plasma glucose concentrations, overall CHO malabsorption is minimal (as reflected by breath hydrogen and hormones) and without symptoms. It, therefore, may be useful in treating type II diabetes mellitus.

Effect of chronic amylase inhibition on pancreatic growth and acinar cell secretory function in rats

Wheat amylase inhibitor (WAI) was given to growing rats to determine whether chronic inhibition of intraluminal amylase activity alters pancreatic growth, pancreatic enzyme composition, and secretory responsiveness to cholecystokinin octapeptide (CCK-OP) and carbachol. For 21 days 13 rats were fed amylase inhibitor (AI) as 2.72% of the weight of their food; 13 were pair-fed controls (PFC), and 12 were controls with free access to food (FAC). Amylase and lipase secretion was measured from isolated pancreatic acini in response to CCK-OP (10(-12)-10(-8) M) and carbachol (10(-8)-10(-3) M). AI and PFC rats had similar food intakes and weight gains, pancreatic weights, and contents of enzymes (amylase, lipase, trypsin, chymotrypsin), protein, and RNA, but these measurements were significantly reduced compared to those of FAC rats. DNA contents per milligram of pancreas and per gram of body weight and amylase/DNA and trypsin/DNA were similar among all groups. Lipase/DNA and chymotrypsin/DNA in AI rats were the same as in PFC rats but significantly lower than in FAC rats. In response to CCK-OP, amylase secretion was similar in all three groups, but in response to carbachol amylase secretion was significantly less in AI compared to PFC and FAC rats. Lipase secretion increased in response to CCK-OP in AI compared to PFC and FAC rats but was similar in all three groups in response to carbachol. Long-term inhibition of intraluminal amylase activity suppresses pancreatic growth and content of enzymes and RNA by reducing food intake and weight gain and also decreases acinar cell secretion of amylase in response to carbachol and increases lipase secretion in response to CCK-OP.

1996 Comfort Symposium on Pancreatic Carcinogenesis

This article summarizes the proceedings of the 1996 Comfort Symposium on Pancreatic Carcinogenesis that took place at the Mayo Clinic in Rochester, Minnesota, September 11-13, 1996. The annual series of Comfort lectures are aimed at discussing leading theories and advanced technological developments in the area of pancreatic research. The goals of this year's symposium were to summarize epidemiologic and experimental findings in the field of pancreatic cancer research, to foster communications among scientists studying this disease, and to identify areas of research that are likely to bridge the gaps between basic science and patient care. The topics discussed included (i) current algorithms for the diagnosis of early pancreatic cancer, (ii) animal and cellular models of pancreatic carcinogenesis, (iii) mechanisms of pain in pancreatic cancer, (iv) the role of signaling cascades and transcription factors in the regulation of pancreatic cell growth and differentiation, (v) methods to study genetic alterations associated with neoplastic diseases, and (vi) recent developments in gene-targeting techniques. The lectures and discussions during the symposium successfully achieved the goals outlined above and resulted in the identification of novel areas of research that may increase our understanding of the etiology and pathogenesis, and lead to early diagnosis and treatment of pancreatic cancer.

Survival of human pancreatic enzymes during small bowel transit: effect of nutrients, bile acids, and enzymes

The activity of pancreatic enzymes declines during aboral intestinal transit. We tested the hypothesis that survival of pancreatic enzyme activities during intestinal transit is affected by amounts or concentrations of calories, nutrients, bile acids, or pancreatic enzymes entering the segments of the small intestine. An oroileal tube was placed in 26 healthy humans. The tube had duodenal, jejunal, and ileal infusion ports for nonabsorbable markers and aspiration ports in the distal duodenum, distal jejunum, and distal ileum. Four infusates of different proportions of protein, fat, and carbohydrate were infused continuously into the duodenum at 40, 90, and 160 kcal/h. Of the nutrients infused into the proximal duodenum, 21 +/- 3, 51 +/- 7, and 39 +/- 5% of fat, protein, and carbohydrate, respectively, were delivered to the distal duodenum. During duodenoileal transit, lipase, chymotrypsin, amylase, and trypsin lost 71 +/- 5, 63 +/- 5, 43 +/- 7, and 38 +/- 9% of activity, respectively (P < 0.01 vs. distal duodenum). During duodenojejunal transit, the activity of each enzyme decreased more than 35% (P < 0.01 vs. distal duodenum), and infusion of more calories into the duodenum improved survival of all enzymes except trypsin (P < 0.05). During jejunoileal transit, greater amounts and concentrations of calories and carbohydrate improved survival of only lipolytic activity (P < 0.01, P < 0.05, respectively), and loss of lipolytic activity correlated directly with delivery of bile acids (r = 0.56, P = 0.05) and chymotrypsin (r = 0.80, P = 0.001) to the distal jejunum. We conclude that intraluminal nutrients increase survival of enzyme activities in the proximal intestine. After absorption of nutrients, the action of chymotrypsin and bile acids decrease lipolytic activity more than activity of other enzymes.

Bacterial lipase and high-fat diets in canine exocrine pancreatic insufficiency: a new therapy of steatorrhea?

BACKGROUND & AIMS

Nutrients and properties of lipases affect survival of lipolytic activity during aboral gastrointestinal transit. Whether different doses and formulations of bacterial lipase and diets affect steatorrhea was tested in pancreatic-insufficient dogs.

METHODS

A dose of 0-600,000 IU of powdered and 135,000 and 300,000 IU of liquid bacterial lipase was given with a standard meal to 5 dogs with ligated pancreatic ducts. In 4 dogs, 0 or 300,000 IU (normal 6-hour postprandial amount) of powder bacterial lipase was also given with five meals containing 850 kcal with different nutrient caloric densities (mixture design). Coefficients of fat absorption during 72-hour fecal balance studies were used to assess treatments.

RESULTS

With the standard meal, powder bacterial lipase reduced steatorrhea in a dose-dependent manner (P = 0.03), and 135,000 and 300,000 IU of the liquid form decreased steatorrhea more than powder bacterial lipase (P = 0.017 and 0.057, respectively). Coefficients of fat absorption with 300,000 IU of powder bacterial lipase correlated (r2 = 0.79; P < 0.001) with increasing proportions of fat calories in diets.

CONCLUSIONS

Liquid bacterial lipase decreases steatorrhea more than powder, and 300,000 IU of powder bacterial lipase ingested with high-fat meals corrects canine pancreatic steatorrhea. The combination of adequate mixing of small amounts (milligrams) of bacterial lipase and high-fat meals abolishes canine steatorrhea and may abolish human pancreatic steatorrhea.

Hereditary pancreatitis and the risk of pancreatic cancer. International Hereditary Pancreatitis Study Group

BACKGROUND

Hereditary pancreatitis is an autosomal-dominant disease, with a variable expression and an estimated penetrance of 80%. The gene for this disease has recently been mapped to chromosome 7q35, and the defect is believed to be caused by a mutation in the cationic trypsinogen gene. Acute attacks of abdominal pain begin early in life and the disease often progresses to chronic pancreatitis. Although the risk of pancreatic cancer is thought to be increased in more common types of chronic pancreatitis, the frequency of pancreatic cancer in the inherited type of pancreatitis is uncertain.

PURPOSE

The aim of this study was to assess the frequency of pancreatic cancer and other tumors in patients with hereditary form of pancreatitis.

METHODS

To determine the natural history of hereditary pancreatitis, we invited all members of the American Pancreatic Association and the International Association of Pancreatology to participate in a longitudinal study of this rare form of pancreatitis. The initial criteria for patient eligibility were as follows: early age (< or = 30 years) at onset of symptoms, positive family history, and absence of other causes. From April 1995 through February 1996, 37 physicians from 10 countries contributed medical records of 246 (125 males and 121 females) patients thought to have hereditary pancreatitis as the most likely diagnosis. This group included 218 patients where the diagnosis appeared to be highly probable and 28 additional patients where the diagnosis of hereditary pancreatitis was less certain: 25 patients who had relatively late onset of disease and a positive family history and three patients with onset of disease before age 30 years but with an uncertain family history. We reviewed all causes of death and compared the observed to the expected frequency of cancer in this historical cohort of patients with hereditary pancreatitis. The strength of the association between pancreatitis and pancreatic cancer was estimated by the standardized incidence ratio (SIR), which is the ratio of observed pancreatic cancer cases in the cohort to the expected pancreatic cancers in the background population, adjusted for age, sex, and country.

RESULTS

The mean age (+/- standard deviation [SD]) at onset of symptoms of pancreatitis was 13.9 +/- 12.2 years. Compared with an expected number of 0.150, eight pancreatic adenocarcinomas developed (mean age +/- SD at diagnosis of pancreatic cancer: 56.9 +/- 11.2 years) during 8531 person-years of follow-up, yielding an SIR of 53 (95% confidence interval [CI] = 23-105). The frequency of other tumors was not increased: SIR = 0.7 (95% CI = 0.3-1.6). Eight of 20 reported deaths in the cohort were from pancreatic cancer. Thirty members of the cohort have already been tested for the defective hereditary pancreatitis gene: all 30 carry a mutated copy of the trypsinogen gene. The transmission pattern of hereditary pancreatitis was known for 168 of 238 patients without pancreatic cancer and six of eight with pancreatic cancer. Ninety-nine of the 238 patients without pancreatic cancer and six of the patients with pancreatic cancer inherited the disease through the paternal side of the family. The estimated cumulative risk of pancreatic cancer to age 70 years in patients with hereditary pancreatitis approaches 40%. For patients with a paternal inheritance pattern, the cumulative risk of pancreatic cancer is approximately 75%.

CONCLUSIONS

Patients with hereditary pancreatitis have a high risk of pancreatic cancer several decades after the initial onset of pancreatitis. A paternal inheritance pattern increases the probability of developing pancreatic cancer.

Role of extrinsic innervation in carbohydrate-induced ileal modulation of pancreatic secretion and upper gut function

Previously we showed that carbohydrate (CHO) in the ileum slowed gastric emptying and increased pancreatic amylase secretion relative to that of other enzymes. Our aim here was to determine if extrinsic innervation of the jejunoileum participates in the CHO-induced ileal modulation of postprandial upper gut function. Six dogs were studied before and 2-3 weeks after in situ neural isolation of the jejunoileum (complete extrinsic denervation). Gastric emptying (GE) and pancreatic amylase secretion were quantitated for 4 h after a 300-ml meal containing 3H-PEH (liquid marker) and 99mTc sulfur colloid cooked with eggs (solid marker). Coincident with feeding, we started a distal ileal infusion of 150 mM NaCl or 40 mg.min-1 CHO. Extrinsic denervation abolished the slowing of GE of liquids and solids and the augmented increase in amylase and trypsin in relation to solid emptying seen in the neurally intact dogs prior to denervation. Denervation also abolished the decrease in total pancreatic exocrine secretion in response to ileal CHO. Increases in plasma concentrations of peptide YY (PYY) were correlated temporally with decreased GE of solids and increased exocrine secretion during ileal CHO in neurally intact dogs, but no increases in PYY release occurred after extrinsic denervation. Extrinsic denervation of the jejunoileum abolished the effect of ileal CHO on GE of liquids and solids, the decrease in total amylase secretion during ileal CHO, and the relative increase in enzyme secretion expressed as total enzyme output per percentage solid marker emptied. Extrinsic innervation of the jejunoileum mediates ileal modulation of GE and the relationship of amylase secretion to GE of solids. The mechanism of this effect may be via neurally mediated release of PYY.

What is the best biochemical test to diagnose acute pancreatitis? A prospective clinical study

OBJECTIVE

To determine which biochemical test is best to distinguish acute pancreatitis from other pancreatic and nonpancreatic diseases associated with hyperamylasemia.

DESIGN

We conducted a prospective clinical study of 836 consecutive patients who had a total serum amylase test requested by a physician during a 7-month period.

MATERIAL AND METHODS

Radioimmunoassay and enzymatic activity methods were used to measure pancreas-specific proteins of varied size, charge, and stability. In addition, scoring systems were used for the diagnosis of pancreatitis, and statistical analyses were done to determine sensitivity and specificity.

RESULTS

We found minor differences in sensitivity and specificity for diagnosis of acute pancreatitis among pancreatic isoamylase, phospholipase A2, colipase, lipase, and carboxylester lipase. Of these tests, the combination of isoamylase and phospholipase A2 had a small but statistically significant increased sensitivity (90%; 95% confidence interval [CI] = 74 to 98%) and specificity (93%; 95% CI = 91 to 95%) over isoamylase (90% and 92%, respectively; 95% CI = 90 to 94%) and phospholipase A2 (90% and 75%, respectively; 95% CI = 72 to 78%) alone for the diagnosis of acute pancreatitis.

CONCLUSION

Pancreas-specific proteins are satisfactory for diagnosing acute pancreatitis if the test is validated by the laboratory. Clinically, the slight advantage of using both isoamylase and phospholipase A2 does not outweigh the expense of performing two assays; we recommend using isoamylase to diagnose acute pancreatitis.

Character of a wheat amylase inhibitor preparation and effects on fasting human pancreaticobiliary secretions and hormones

BACKGROUND & AIMS

Amylase inhibition induces carbohydrate tolerance, satiety, and weight loss and prolongs gastric emptying, effects that may be useful in the treatment of obesity and non-insulin-dependent diabetes mellitus. The aim of this study was to determine (1) purity of a wheat amylase inhibitor preparation, (2) intraduodenal concentration of the wheat amylase inhibitor preparation that inhibits > 90% amylase activity (which causes carbohydrate malabsorption), and (3) if the inhibitor alters pancreaticobiliary secretions or intraluminal pH.

METHODS

High-performance liquid chromatography followed by electrophoresis and sodium dodecyl sulfate-polyacrylamide gel electrophoresis were used for characterization. Groups of 3 subjects received intraduodenal infusions of 3.0, 4.5, or 6.0 mg/mL of the inhibitor for 90 minutes during the middle of a 270-minute essential amino acid solution infusion (which stimulates 50% maximal pancreatic enzyme secretion). Pancreatic enzyme and bile acid delivery to the duodenum were measured for a 270-minute period.

RESULTS

The inhibitor is 96% protein, 59% containing 0.19, 0.28, 0.38, and 0.53 inhibitors. The 0.38 inhibitor has the most antipancreatic alpha-amylase activity. The inhibitor reduced amylase activity in the duodenum dose dependently (r = 0.7; P = 0.04); > 4 mg/mL inhibited > 90% amylase activity but did not affect delivery of other enzymes or bile acids to the duodenum or gastric or duodenal pH.

CONCLUSIONS

The preparation has a high protein purity and a high specific activity against alpha-amylase activity and effectively inhibits human pancreatic amylase activity secreted into the duodenum.

Intraductal papillary-mucinous tumors of the pancreas: clinicopathologic features, outcome, and nomenclature. Members of the Pancreas Clinic, and Pancreatic Surgeons of Mayo Clinic

BACKGROUND & AIMS

Intraductal papillary-mucinous tumor (IPMT) of the pancreatic ducts is increasingly recognized. This study investigated if clinical, imaging, or, histological features predicated outcome, formulated a treatment algorithm, and clarified relationships among IPMT, mucinous cystic neoplasms of the pancreas (MCN), and chronic pancreatitis.

METHODS

The medical records, radiographs, and pathological specimens of 15 patients with IPMT (dilated main pancreatic duct or branch ducts with mucin overproduction) who were evaluated between October 1983 and January 1994 were reviewed.

RESULTS

One patient had hepatic metastases. Fourteen underwent an operation (6 distal pancreatectomy, 4 total pancreatectomy, and 4 pancreaticoduodenectomy); all had dysplastic intraductal epithelium and chronic pancreatitis, whereas 3 had invasive adenocarcinoma. After a median of 25 months, 10 patients were alive; 3 of 4 with malignant and 2 of 11 with benign IPMT died (P < 0.05). Patients with or without carcinoma had similar clinical and radiographic features. A clinical diagnosis of chronic pancreatitis had been made in 9 patients with benign IMPT and in none with malignant IPMT (P < 0.05).

CONCLUSIONS

IPMT is a dysplastic and likely precancerous lesion that is frequently diagnosed as chronic pancreatitis and is separate from MCN. Because it is not possible to distinguish noninvasive from invasive IPMT preoperatively, complete surgical excision of the dysplastic process is our treatment of choice whenever appropriate.

Nutrients and cyclical interdigestive pancreatic enzyme secretion in humans

BACKGROUND AND AIMS

It is hypothesised that nutrients increase pancreatic enzyme secretion by converting cyclical interdigestive secretion to a non-cyclical pattern. This study tested the hypotheses that nutrients do not interrupt cycles and determined the relation of nutrients, calories, and osmotic load to the rate of pancreatic secretion.

METHODS

Twenty six healthy persons were intubated with oroduodenal and orogastric tubes. Each had one of four different solutions containing 12 to 36% of calories as protein, 24 to 48% as fat, and 40 to 64% as carbohydrate infused into the duodenum at 40, 90, or 160 kcal/h for 300 minutes. Nine g/l sodium chloride (290 mOsm) was added to 16 infusates; osmolality of the other 10 infusates was 24 to 98 mOsm. Pancreatic enzyme outputs were measured every 15 minutes and peaks of enzyme secretion were identified.

RESULTS

The number of enzyme peaks was similar for the different infusates and the proportion of nutrients in the infusates did not affect secretion of individual enzymes. The nadir, but not the peak of the cycles of enzyme outputs correlated with increasing the caloric load (r = 0.55, p < 0.003 for nadir:peak ratio). Increasing osmolality did not affect cycling but reduced (p < 0.001) enzyme output.

CONCLUSION

Nutrients entering the duodenum do not abolish cycles of enzyme secretion; instead they modulate cycles by increasing the nadir. Forty and 90 kcal infusions submaximally stimulate pancreatic secretion and might be used in patients with pancreatitis without producing pain; adding sodium chloride to solutions should increase this effect.

Intraileal carbohydrate regulates canine postprandial pancreaticobiliary secretion and upper gut motility

BACKGROUND & AIMS

The effect of nutrients in the distal small intestine or colon on postprandial upper gut function is incompletely understood. The aim of this study was to determine if carbohydrate in the ileum or proximal colon of dogs affects postprandial pancreaticobiliary secretion, gastrointestinal transit, and circulating concentrations of certain gastrointestinal regulatory peptides.

METHODS

Seven dogs were prepared with permanent infusion and aspiration catheters in the duodenum and ileum and an infusion catheter in the cecum. Coincident with eating a meal containing liquid and solid markers, ileal or colonic (n = 5 dogs for each) infusion were begun of isosmolar 0.9% NaCl or carbohydrate in a 3:1 ratio of starch to glucose. Pancreatic enzyme output, bile acid delivery, gastrointestinal polypeptide, and plasma concentrations of pancreatic polypeptide, neurotensin, and peptide YY were measured for 6 hours postprandially.

RESULTS

Carbohydrate infusion in the ileum, but not in the proximal colon, increased amylase secretion and plasma peptide YY, slowed gastric emptying of liquids and solids, slowed small intestinal transit, and decreased bile acid delivery into the duodenum (P < 0.05 in each).

CONCLUSIONS

Carbohydrate in the ileum regulates postprandial exocrine pancreatic enzyme secretion and other postprandial upper gut functions. Peptide YY may play a role in this regulation.

Diagnosis of foregut duplication cysts by endoscopic ultrasonography

BACKGROUND & AIMS

Foregut duplication cysts are rare congenital anomalies of enteric origin found most commonly in children and rarely in adults. They are usually found in adults on routine radiological studies and represent a challenging diagnostic problem. Conventional imaging tests do not lead to a conclusive diagnosis. With endoscopic ultrasonography, it is possible to distinguish between cystic and solid masses and to accurately establish the location of the cyst in relation to the gastrointestinal wall and to the mediastinum.

METHODS

Seven patients who had endoscopic ultrasonography performed because of differentiation between a cystic or solid mass lesion in the chest or abdomen could not be made with conventional radiological methods are described.

RESULTS

In all patients, a definite diagnosis was established by endoscopic ultrasonography. The diagnosis was confirmed in 2 patients after surgical excision.

CONCLUSIONS

Surgery can be avoided in patients with asymptomatic enteric duplication cysts diagnosed by endoscopic ultrasonography.

Exocrine pancreatic insufficiency after allogeneic bone marrow transplantation

Several reports suggest a relationship between bone marrow transplantation and pancreatic damage. The authors describe two patients with pancreatic insufficiency after bone marrow transplantation. The first patient had weight loss arising from steatorrhea secondary to severe pancreatic insufficiency (lipase output result <3% of normal) due to pancreatic atrophy. The second patient had steatorrhea secondary to intestinal bacterial overgrowth, but moderate pancreatic insufficiency was present (results of trypsin and lipase outputs were 50 and 30% of normal). Before the diagnosis of pancreatic insufficiency, both patients had acute graft vs host disease and the second patient had chronic graft vs host disease. We conclude that graft vs host disease after bone marrow transplantation may damage the pancreas. Patients with persistent malabsorption after bone marrow transplantation should be tested for exocrine pancreatic insufficiency.

Effect of a wheat amylase inhibitor on canine carbohydrate digestion, gastrointestinal function, and pancreatic growth

BACKGROUND/AIMS

Chronic amylase inhibition might be useful to treat diabetes mellitus and obesity. Duodenal and ileal cannulas were placed in 8 dogs to determine if long-term ingestion of a wheat amylase inhibitor maintained amylase inhibition or affected gastrointestinal or metabolic function or pancreatic growth.

METHODS

Five dogs were fed and 3 were not fed 1.5 g of the inhibitor with meals for 9 weeks. Postprandial and cholecystokinin octapeptide stimulated pancreatic secretion, and fecal balance studies were performed at intervals. After the experiment, the pancreas was analyzed.

RESULTS

Weight loss was similar in both groups. Amylase inhibition persisted throughout the 9 weeks; it declined from 91% to 37% from the first to the sixth postprandial hour. Amylase inhibition decreased plasma glucose levels during the first hour (P < 0.05), increased carbohydrate delivery to the ileum (315 vs. 555 mg/h; P = 0.002), and increased cholecystokinin octapeptide-stimulated amylase secretion. However, amylase inhibition did not significantly change plasma concentrations of insulin, peptide YY or neurotensin, postprandial pancreatic secretion, gastrointestinal transit or pancreatic weight, and protein or DNA content.

CONCLUSIONS

Prandial ingestion of 1.5 g of the inhibitor for 9 weeks reduces postprandial amylase levels enough to delay carbohydrate digestion and absorption and lower plasma glucose levels without altering pancreatic growth. This dose may be effective to treat diabetes mellitus but not obesity.

The different courses of early- and late-onset idiopathic and alcoholic chronic pancreatitis

BACKGROUND/AIMS

Compared with alcoholic pancreatitis, little is known about the natural history of idiopathic pancreatitis. Two hundred forty-nine patients with alcoholic pancreatitis and 66 patients with idiopathic chronic pancreatitis seen at our institution between 1976 and 1982 were investigated.

METHODS

Records were analyzed retrospectively from the onset of symptomatic disease, and patients were followed up prospectively until 1985. Patients with early-onset (n = 25) and late-onset (n = 41) idiopathic chronic pancreatitis had a median age at onset of symptoms of 19 and 56 years, respectively.

RESULTS

The gender distribution was nearly equal in idiopathic chronic pancreatitis, but 72% of patients with alcoholic pancreatitis were men (P = 0.001 vs. idiopathic). In early-onset idiopathic pancreatitis, calcification and exocrine and endocrine insufficiency developed more slowly than in late-onset idiopathic and alcoholic pancreatitis (P = 0.03). However, in early idiopathic chronic pancreatitis, pain frequently occurred initially (P = 0.003 vs. late and alcoholic) and was more severe (P = 0.04 vs. late and alcoholic). In late-onset idiopathic pancreatitis, pain was absent in nearly 50% of patients.

CONCLUSIONS

There are two distinct forms of idiopathic chronic pancreatitis. Patients with early-onset pancreatitis have initially and thereafter a long course of severe pain but slowly develop morphological and functional pancreatic damage, whereas patients with late-onset pancreatitis have a mild and often a painless course. Both forms differ from alcoholic pancreatitis in their equal gender distribution and a much slower rate of calcification.

Prognosis of chronic pancreatitis: an international multicenter study. International Pancreatitis Study Group

OBJECTIVES

The aim of this study was to determine which factors predict mortality in a cohort of patients with chronic alcoholic and nonalcoholic pancreatitis. Patients with chronic pancreatitis are known to have a reduced life expectancy, but the quantitative relationship between various clinical features and survival is unclear.

METHODS

We evaluated survival among 2015 subjects with chronic pancreatitis treated at seven centers located in six countries.

RESULTS

Mean age at diagnosis was 46 +/- 13 yr and mean duration of follow-up was 7.4 +/- 6.2 yr. Overall survival at 10 yr was 70% (95% confidence interval (CI), 68-73%) and at 20 yr was 45% (95% CI, 41-49%). Survival was significantly less than in the background population. There were 559 deaths observed among those with chronic pancreatitis compared with an expected number of 157.4, yielding a standardized mortality ratio (SMR) of 3.6 (95% CI, 3.3-3.9). Older subjects and those with alcoholic pancreatitis had a significant reduction in survival. In a multivariate analysis, mortality of middle-aged and older subjects was 2.3 (95% CI, 1.8-2.8) and 6.3 (95% CI, 4.7-8.3) times greater than subjects less than 40 yr at diagnosis. Smoking (hazard ratio, 1.4; 95% CI, 1.0-1.9), drinking (hazard ratio, 1.6; 95% CI, 1.2-2.2), or development of cirrhosis (hazard ratio, 2.5; 95% CI, 2.0-3.2) increased the risk of death during the observation period, but we observed no survival difference in operated vs. nonoperated patients.

CONCLUSIONS

Age at diagnosis, smoking, and drinking are major predictors of mortality in patients with chronic pancreatitis.

Lipolytic activity of bacterial lipase survives better than that of porcine lipase in human gastric and duodenal content

BACKGROUND/AIMS

Treatment of pancreatic steatorrhea with porcine lipase is unsatisfactory because it is rapidly denatured by acidic intraluminal conditions. The aim of this study was to determine if bacterial lipase is resistant to acid denaturation and is active in the presence of bile acids by comparing its stability with that of porcine lipase in gastric and duodenal juice obtained from six patients undergoing a cholecystokinin octapeptide pancreatic function test.

METHODS

After inactivating native lipolytic activity, both juices were altered to simulate fasting and postprandial conditions in normal patients and patients with pancreatic insufficiency. Gastric juice was adjusted to pH 2, 3, 4, or 6, duodenal juice to pH 4 or 6, and bile acid concentrations to 4 or 12 mmol/L. Nutrients were added to one half of the samples. Initial bacterial or porcine lipolytic concentrations were 25 or 250 U/mL. After a 1-hour incubation at 37 degrees C, lipolytic activity was remeasured.

RESULTS

In gastric juice, more bacterial lipolytic activity survived than porcine lipolytic activity at both concentrations in the absence of nutrients and at a concentration of 25 U/mL with nutrients (P < 0.05). In duodenal juice, more bacterial lipolytic activity survived than porcine activity at pH 4 under all test conditions (P < 0.05).

CONCLUSIONS

Bacterial lipolytic activity should survive better within the gastrointestinal lumen than porcine lipolytic activity and be more effective to treat steatorrhea.

Separation of canine pancreatic juice proteins by hydrophobic interaction chromatography preserves enzyme activity

To measure the synthesis of pancreatic enzymes requires the separation of pancreatic juice proteins. The aim of the present study was to separate amylase, lipase, and trypsinogen present in dog pancreatic juice by using a hydrophobic interaction high-performance liquid chromatography (HPLC). During a 40-min, four-stage gradient of decreasing sodium sulfate concentration, dog pancreatic juice proteins were separated into 10 peaks based on hydrophobicity. Amylase, lipase, and trypsinogen were identified in HPLC fractions by measuring enzyme activity and molecular weight. Amylase and lipase were present in separate peaks. By sodium dodecyl sulfate (SDS) gel electrophoresis, peak 10, the only peak with amylase activity had a single protein, but peak 3, containing lipase, and peak 9, containing trypsinogen, had two or more proteins. Trypsinogen activity was also detected as a main protein in peak 5 and the molecular weight of this protein, 26 kDa corresponds to that of dog trypsinogen. Trypsinogen was not identified in peak 9 by SDS gel electrophoresis because other proteins were close to this location on the gel. In summary, the proteins and activities of amylase, lipase, and two trypsinogens secreted by the dog pancreas can be separated rapidly by hydrophobic interaction liquid chromatography. Also, this one step procedure recovers 87% of amylase from dog pancreatic juice as a single protein.

Role of the duodenum in postprandial release of pancreatic and gastrointestinal hormones

In previous studies we found that duodenectomy abolished the interdigestive cycles of plasma motilin and pancreatic polypeptide (PP). In the current studies, we tested the hypothesis that an intact duodenopancreatic axis is necessary for normal postprandial release of pancreatic (PP, insulin) and gut peptides (gastric inhibitory peptide, GIP; cholecystokinin octapeptides, CCK-8; neurotensin; and gastrin). Consequently, we measured plasma concentration of pancreatic and gut hormones in normal and duodenectomized dogs after gavage feeding of a 250-ml liquid formula diet in conscious animals. After completing the experiments, pancreatic tissue concentrations of PP and insulin were measured. Removal of the duodenum was associated with decreases in postprandial plasma concentrations of PP (p < 0.05) and insulin (p < 0.05) and in pancreatic tissue concentrations of insulin (p = 0.01). Duodenectomy, however, did not alter postprandial plasma concentrations of GIP, CCK-8, neurotensin, or gastrin nor pancreatic tissue concentrations of PP. These effects of duodenectomy may be due to disruption of duodenopancreatic neural connections or loss of vagus sensitive (non-GIP) humoral factors. Decreased postprandial insulin concentrations may be due to lack of a neural or humoral insulinotropic factor arising from the duodenum.

Cholinergic regulation of phase II interdigestive pancreatic secretion in humans

Small fluctuations in cholinergic input may be involved in the regulation of human interdigestive pancreatic secretion. To determine the effects of small changes in cholinergic tone on phase II interdigestive trypsin secretion, we gave cholinergic agonists or antagonists to 17 healthy fasting subjects who underwent gastrointestinal intubation. Duodenal trypsin outputs, gastroduodenal motility, and plasma levels of pancreatic polypeptide (PP) as a marker of cholinergic tone were measured during intravenous infusion of bethanechol (0, 5, or 40 micrograms.kg-1.h-1) or atropine (0, 4, or 16 micrograms.kg-1.h-1) given during phase II alone or in combination based on a 3 x 3 factorial design. Data were evaluated by a response surface analysis of the average log values for the test period (using the average of log values of the control period as a covariate). Bethanechol increased trypsin output (p < 0.05) and plasma concentrations of PP (p < 0.05) within the ranges of spontaneous fluctuations of trypsin output and PP during phase II, but did not disrupt the periodicity of pancreatic secretion or the characteristic cyclical pattern of interdigestive motility and induction of phase III activity. Atropine markedly decreased trypsin output (p < 0.05) and plasma concentrations of PP (p < 0.05) and abolished the cycling of interdigestive pancreatic secretion and motor activity. These data suggest the hypothesis that cholinergic pathways participate in the control of interdigestive pancreatic secretion during phase II, while enzyme secretion during phase III may be regulated by other mechanisms.