The specific activities of human digestive lipases measured from the in vivo and in vitro lipolysis of test meals

BACKGROUND & AIMS: The lipolytic potential of digestive lipases in vivo has always been deduced so far from their in vitro activities under nonphysiologic conditions. In the present study, the specific activities of human gastric lipase (HGL) and pancreatic lipase (HPL) were measured on dietary triglycerides (TGs) during test meal lipolysis. METHODS: Healthy human volunteers ingested a liquid or solid meal. The specific activities of HGL and HPL were estimated from the lipase and free fatty acid (FFA) outputs at the postpyloric and duodenal levels, respectively. Based on the in vivo data, lipolysis was also performed in vitro by mixing the meal either with gastric juice and subsequently with pancreatic juice and bile or with purified HGL and HPL. FFAs were measured by thin-layer chromatography, and the specific activities of HGL and HPL were expressed as micromoles of FFA per minute per milligram of lipase. RESULTS: In vitro, the specific activities on the liquid meal TGs were 32 (gastric juice) and 34 (pure lipase) micromol x min(-1) x mg(-1) with HGL and 47 (pancreatic juice) and 43 (pure lipase) micromol x min(-1). mg(-1) with HPL. The specific activities on the solid meal TGs were 33 (gastric juice) and 32 (pure lipase) micromol x min(-1) x mg(-1) with HGL and 12 (pancreatic juice) and 15 (pure lipase) micromol x min(-1) x mg(-1) with HPL. The in vivo values obtained were in the same range. The secretory lipase outputs were 21.6+/-14.5 mg HGL and 253.5+/-95.5 mg HPL with the liquid test meal and 15.2+/-5.1 mg HGL and 202.9+/-96.1 mg HPL with the solid test meal. Conclusions: The specific activities of HGL and HPL on meal TGs were much lower than those measured in vitro under optimized assay conditions (1300-8000). However, these low specific activities are enough for the meal TGs to be completely lipolysed, given the amounts of HGL and HPL secreted during a meal.     

Study of the gastrointestinal bioavailability of a pancreatic extract product (Zenpep) in chronic pancreatitis patients with exocrine pancreatic insufficiency

IntroductionThe Food and Drug Administration in 2006 required that all pancreatic enzyme products demonstrate bioavailability of lipase, amylase, and protease in the proximal small intestine.MethodsIn this phase I open-label, randomized, crossover trial, 17 adult chronic pancreatitis (CP) patients with severe exocrine pancreatic insufficiency (EPI) underwent two separate gastroduodenal perfusion procedures (Dreiling tube suctioning and [¹⁴C]-PEG instillation by an attached Dobhoff tube in the duodenal bulb). Patients received Ensure Plus® alone and Ensure Plus with Zenpep (75,000 USP lipase units) in random order. The bioavailability of Zenpep was estimated by comparing the recovery of lipase, amylase, chymotrypsin activity in two treatment conditions. ¹⁴C-PEG was used to correct duodenal aspirates volume. The primary efficacy endpoint was lipase delivery in the duodenum after Zenpep administration under fed conditions. Secondary efficacy endpoints included chymotrypsin and amylase delivery, serum CCK levels, and measuring duodenal and gastric pH.ResultsZenpep administration with a test meal was associated with significant increase in duodenal aspiration of lipase (p = 0.046), chymotrypsin (p = 0.008), and amylase (p = 0.001), compared to the test meal alone, indicating release of enzymes to the duodenum. Lipase delivery was higher in the pH subpopulation (the efficacy population with acid hypersecretors excluded) (p = 0.01). Recovery of [¹⁴C]-PEG was 61%. Zenpep was generally well tolerated. All adverse events were mild and transient.ConclusionsIn CP patients with severe EPI, lipase, chymotrypsin and amylase were released rapidly into the duodenum after ingestion of Zenpep plus meal compared to meals alone. Results also reflected the known pH threshold for enzyme release from enteric coated products.     

Effects of lansoprazole on human gastric lipase secretion and intragastric lipolysis in healthy human volunteers.

BACKGROUND: Lansoprazole is a potent proton-pump inhibitor (PPI) of parietal cells, which reduces the secretion of gastric acid. Although human gastric lipase (HGL) is produced only by the chief cells of the stomach, the possibility that interactions may occur between lansoprazole and HGL has never been addressed so far in humans. The aim of this study was therefore to quantify the effects of lansoprazole on HGL secretion and intragastric lipolysis during the ingestion of test meals by healthy human volunteers. METHODS: Six healthy volunteers were intubated twice with a gastric and a duodenal tube, before ingesting a standard liquid test meal alone (-PPI experiments) and after 7 days of lansoprazole treatment (+PPI experiments). The HGL concentration was assessed in gastric and duodenal samples by measuring the lipase activity using a pH-stat, and the lipolysis products were quantified by performing thin layer chromatography. The level of intragastric lipolysis was defined as the percentage acyl chains released from the meal triglycerides. The pyloric outputs of HGL and lipolysis products were calculated, based on the use of a non-absorbable marker added to the meal. RESULTS: The pH of the gastric contents was significantly higher in the +PPI experiments than in the -PPI experiments (p < 0.05), since mean values of 4.3 +/- 2.5 and 2.2 +/- 1.6, respectively, were recorded at the end of the gastric emptying of the meal. The HGL concentrations recorded during the meal were found to be higher in the experiments with lansoprazole (p < 0.05) than in those without lansopra- zole, but the HGL secretion levels (-PPI: 15.4 +/- 8.0 mg; +PPI: 19.0 +/- 7.4 mg) and the intragastric lipolysis (-PPI: 24.0 +/- 8.0%; +PPI: 23.6 +/- 6.8%) were not significantly affected by lansoprazole (p > 0.05 in both cases). CONCLUSION: Lansoprazole affected neither the HGL secretion nor the intragastric lipolysis levels, although an increase was observed in the intragastric pH at the end of the gastric emptying of the meal. The HGL concentration increased, however, due to the decrease in the acid secretion process, resulting in less diluted gastric contents.     

Exocrine pancreatic function in man after cytotoxic treatment.

Using the secretin-pancreozymin test, the function of the exocrine pancreas was studied in patients with malignant disease before and after massive-dose therapy with cyclophosphamide and before and after combined cytotoxic treatment (as outlined by De Vita). The investigations further included an examination of the exocrine pancreatic function in subjects on maintenance therapy with clyclophosphamide of Myleran and a comparison with the exocrine pancreatic function in a group of controls. In the patients on massive-dose or continued therapy with cyclophosphamide the volume of the duodenal secretion and the bicarbonate, electrolyte and enzyme outputs in the duodenal secretion remained essentially unchanged. In contrast, cytotoxic combination treatment resulted in decreased activities of amylase and lipase, and in some cases of trypsin. After maintenance treatment with Myleran a reduction of the trypsin and amylase activities was detectable; chymotrypsin and lipase were found to be slighthly lowered.     

Elastase Secretion in Pancreatic Disease

To estimate the diagnostic value of elastase output in the duodenal aspirates during a pancreozymin secretin test, elastase as well as amylase, chymotrypsin, trypsin, and lipase was determined in 46 controls and 61 patients with various disease. The elastase output decreased significantly in chronic pancreatitis (mild exocrine insufficiency 13 and advanced eight), pancreatic cancer (n = 10), and liver cirrhosis (n = 14) when compared with the controls. The outputs of the four other enzymes also decreased in chronic pancreatitis and pancreatic cancer, not in liver cirrhosis. Low elastase output was found in four of 13 chronic pancreatitis patients with mild exocrine insufficiency, whereas low outputs of the other enzymes were observed in only one or less of the 13. The ratio of elastase to amylase alone was significantly lower in the pancreatic diseases. The results suggest that elastase is the most susceptible enzyme to pancreatic dysfunction and that its output and its ratio to amylase output provide a valuable index to assess the enzyme secretory capacity in the pancreatic diseases.     

Fecal elastase-1 determination: 'gold standard' of indirect pancreatic function tests?

BACKGROUND: Tubeless pancreatic function tests measuring the content of elastase-1 and the activity of chymotrypsin in stool are used with different cut-off levels and with varying success in diagnosing functional impairment of the pancreas. The aim of our study was to re-evaluate the sensitivity and specificity of elastase-1 and chymotrypsin in stool in the assessment of exocrine pancreatic insufficiency. METHODS: In 127 patients displaying clinical signs of malassimilation, the secretin-caerulein test ('gold standard'), fecal fat analysis, fecal chymotrypsin activity and fecal elastase-1 concentration were performed. Exocrine pancreatic insufficiency was graded, according to the results of the secretin-caerulein test, into mild, moderate and severe. Chymotrypsin and elastase-1 in stool were estimated using two commercially available test kits. Fecal elastase-1 concentration of 200 and 100 microg/g stool and chymotrypsin activity of 6 and 3 U/g stool were used separately as cut-off levels for calculation. RESULTS: 1) In 65 patients, a normal pancreatic function was found using the secretin-caerulein test. In 62 patients, an exocrine pancreatic insufficiency was found and classified into severe (n = 25), moderate (n = 14) and mild (n = 23). 2) The correlation between fecal elastase-1 and chymotrypsin with duodenal enzyme outputs of amylase, lipase, trypsin, chymotrypsin and elastase-1 ranged between 33% and 55% and 25% and 38%, respectively. 3) Using a cut-off of 200 microg elastase-1/g, stool sensitivities of fecal elastase-1 and fecal chymotrypsin (cut-off: 6 U/g) were 100% and 76%, respectively (P < 0.0001 and P < 0.001 respectively) in severe exocrine pancreatic insufficiency, 89% and 47% respectively (P < 0.001; P = 0.34, respectively) in moderate and 65% for both in mild pancreatic insufficiency. Specificities of elastase-1 and chymotrypsin in stool were 55% and 47%, respectively. 4) Elastase-1 based diagnostic provided a positive predictive value of 50% using a cut-off' 200 microg/g stool in a representative group of consecutively recruited patients with gastroenterological disorders. CONCLUSION: Determination of fecal elastase-1 is highly sensitive in the diagnosis of severe and moderate exocrine pancreatic insufficiency and is of significantly higher sensitivity than fecal chymotrypsin estimation. Specificity for both stool tests is low. Correlation between elastase-1 and chymotrypsin in stool and duodenal enzyme outputs is moderate. Neither test is suitable for screening, as they provide a pathologic result in roughly half of 'non-pancreas' patients.     

Fate of oral enzymes in pancreatic insufficiency.

Oral pancreatic enzyme supplements, including those protected from gastric acidity by enteric coating, often achieve only partial correction of pancreatic steatorrhoea. To characterise the mechanisms involved in vivo, eight patients with steatorrhoea due to advanced pancreatic insufficiency and nine healthy controls were studied. Two sets of studies (small bowel intubation and five day faecal fat quantification) were randomly performed while patients were either on enteric coated pancreatin or equivalent placebo. A 260 cm long multilumen tube was used for double marker perfusion of two 20 cm segments located in the duodenum and in the ileum respectively. Luminal pH, flow, and trypsin and lipase activity outputs were measured at each segment for four hours postcibally. Placebo treated patients with pancreatic steatorrhoea had low enzyme outputs in the duodenal test segment and even lower outputs in the ileal segment. Pancreatin treatment significantly decreased steatorrhoea (p < 0.05) and increased luminal enzyme outputs (p < 0.05). The increase was much greater in the ileal than in the duodenal segment. Thus enteric coated pancreatin treatment abolished the normal gradient between postcibal duodenal and ileal lipase output. The results suggest that enteric coated pancreatin nearly corrects severe pancreatic steatorrhoea. The ingested lipase was utilised inefficiently, however, as luminal enzyme activity in the ileum was enhanced to a greater extent than in the duodenum, and consequently the absorptive potential of the small bowel was only partially utilised.     

Effect of parenteral amino acids on human pancreatic exocrine secretion

Parenteral administration of amino acids has been utilized for the nutritional support of patients with a variety of gastrointestinal disorders including protracted pancreatitis and pancreatic fistulae. However, the effect of parenteral amino acid administration alone on human pancreatic secretion has not been studied. We have studied the short-term effect of parenteral administration of amino acids on pancreatic exocrine secretion in seven healthy men. A double-lumen tube was placed in the duodenum and polyethylene glycol was perfused into the proximal duodenum at the rate of 10 ml/min. A second double-lumen tube was placed in the stomach and bromsulfthalein was perfused into the cardia. Samples of duodenal contents were aspirated and gastric contents recovered during one hour of intravenous saline infusion followed by two hours of an amino acid mixture infusion. Hourly outputs of protein and pancreatic enzymes were determined, correcting for duodenogastric reflux based on concentrations of both markers in the samples. Despite an average increase of 72% in the plasma concentration of the infused amino acids, the outputs of protein, trypsin and amylase did not change significantly during amino acid infusion; the output of lipase decreased significantly during amino acid infusion. Two subjects were given intravenous secretin and cholecystokinin following amino acids; this resulted in increased outputs of protein, trypsin, and amylase in both. We conclude that the parenteral administration of amino acids to healthy young men does not stimulate pancreatic enzyme secretion as measured by the method using duodenal marker perfusion at the rate of 10 ml/min.This research was supported by a grant from U.S. Veterans Administration.     

Effects of non-starch polysaccharides enzymes on pancreatic and small intestinal digestive enzyme activities in piglet fed diets containing high amounts of barley

AIM:To investigate effects of non-starch polysaccharides(NSP)enzymes on pancreatic and small intestinal digestive enzyme activities in piglet fed diets containing high amounts of barley.METHODS:Sixty crossbred piglets averaging 13.5kg were randomly assigned to two treatment groups with three replications (pens) based on sex and mass. Each group was fed on the diet based on barley with or without added NSP enzymes (0.15%) for a 40-d period. At the end of the experiment the pigs were weighed. Three piglets of each group were chosen and slaughtered. Pancreas, digesta from the distal end of the duodenum and jejunal mucosa were collected for determination. Activities of the digestive enzymes trypsin, chymotrypsin, amylase and lipase were determined in the small intestinal sections as well as in homogenates of pancreatic tissue.Maltase,sucrase,lactase and γ-glutamyl transpeptidase (γ-I-) activities were analyzed in jejunal mucosa.RESULTS:Supplementation with NSP enzymes improved growth performance of piglets.It showed that NSP enzymes had no effect on digestive enzyme activities in pancreas,but decreased the activities of proteolytic enzyme,trypsin,amylase and lipase in duodenal contents by 57.56%,76.08%,69.03% and 40.22%(P&lt;0.05) compared with control,and increased γ-GT activities in jejunal mucosa by 118.75%(P&lt;0.05).CONCLUSION:Supplementation with NSP enzymes in barley based diets could improve piglets‘ growth performance,decrease activities of proteolytic enzyme, trypsin, amylase and lipase in duodenal contents and increase γ-GT activities in jejunal mucosa.     

Faecal elastase 1: a novel, highly sensitive, and specific tubeless pancreatic function test.

BACKGROUND: Indirect pancreatic function tests available today are unreliable for clinical practice in early chronic pancreatitis due to their low sensitivity in mild and moderate exocrine pancreatic insufficiency. AIM: To evaluate the sensitivity, specificity, and practicability of faecal elastase 1 determination in patients with mild, moderate, and severe exocrine pancreatic insufficiency categorised according to the secretin-caerulein test as "gold standard'. PATIENTS AND METHODS: Faecal and duodenal elastase 1 concentration (commercial enzyme linked immunosorbent assay (ELISA)), faecal chymotrypsin activity, faecal fat analysis, and the secretin-caerulein test were performed on 44 patients with mild (n = 8), moderate (n = 14), and severe (n = 22) exocrine pancreatic insufficiency and 35 patients with gastrointestinal diseases of non-pancreatic origin. Fifty healthy volunteers were studied as normal controls. Morphological examinations were carried out to definitely confirm or exclude chronic pancreatitis. RESULTS: With a cut off of 200 micrograms elastase 1/g stool the sensitivity was 63% for mild, 100% for moderate, 100% for severe, and 93% for all patients with exocrine pancreatic insufficiency, and specificity was 93%. Values for chymotrypsin were 64% (sensitivity) and 89% (specificity). Significant (p < 0.001) correlations were found for faecal and duodenal elastase with duodenal lipase, amylase, trypsin, volume, and bicarbonate output. Individual day to day variations of faecal elastase 1 concentrations were very low (mean CV = 15%) and sample storage at room temperature is possible for at least one week. CONCLUSIONS: Faecal elastase 1 determination proved to be a highly sensitive and specific tubeless pancreatic function test.     

Total pancreatic insufficiency in pigs: a model to study intestinal enzymes and plasma levels of digestive hormones after pancreatic supplementation by a whole pancreas preparation

Oral pancreatic enzyme replacement therapy generally benefits patients with severe pancreatic deficiency. However, the fate of oral pancreatic supplements in the digestive lumen and their possible effects on circulating gut hormones are only partially known. The purpose of this article is to validate an experimental model that produces total pancreatic insufficiency in pigs, and to study the fate of orally administered Eurobiol, a whole pancreas lyophilized preparation, and its effects on circulating plasma levels of five digestive hormones. Pancreatic insufficiency was created by pancreatic duct ligation, and the duodenal, jejunal and ileal contents were sampled through cannulas before a normal meal and 0.5-24 h later. Blood samples were taken at the same times, and plasma neurotensin, pancreatic polypeptide, secretin, cholecystokinin (CCK), and gastrin were measured. In pigs with pancreatic insufficiency, Eurobiol, given during the meal, induced a significant increase in all enzyme activities in the duodenum and the jejunum, and in the levels of amylase, trypsin, and chymotrypsin in the ileum, relative to placebo. In the duodenum, the peak concentrations of enzyme activities were 19, 11, 17, and 29% (p less than 0.001) of the postprandial peak activities measured in control pigs with an intact pancreas for lipase, amylase, trypsin, and chymotrypsin, respectively. In the jejunum, the same activities were, respectively, 30, 11, 25, and 36% (p less than 0.01-0.001) of normal peaks. In pigs with pancreatic insufficiency, basal and integrated meal-stimulated neurotensin levels were increased; basal, peak, and integrated meal-stimulated pancreatic polypeptide and secretin levels were increased, whereas gastrin and CCK were not different from controls.(ABSTRACT TRUNCATED AT 250 WORDS)     

Influence of exogenous application of pancreatic extracts on endogenous pancreatic enzyme secretion.

The existence of negative feedback inhibition of human pancreatic enzyme secretion by proteases is controversially discussed. We have recently demonstrated that jejunal application of porcine pancreatic extracts, in a dose commonly used to treat digestive insufficiency, stimulated rather than inhibited, human pancreatic enzyme secretion. We have now studied the influence of duodenal application of high concentrations of either pure trypsin or porcine pancreatic extracts with trypsin-equivalent activity, on human pancreatic enzyme secretion. Twenty-three male volunteers were intubated with a gastric tube and a two-lumen jejunal tube to collect secretions separately via the first and third tubes and to perfuse either pure trypsin or porcine pancreatic extracts distal to the pylorus via the second tube. PEG-4.000 was continuously perfused via the second tube to correct for losses of volume. Volunteers received PEG alone during the first hour, phenylalanine during the second, PEG alone again during the third, and either phenylalanine together with trypsin or porcine pancreatic extracts during the fourth h. Activities of lipase, amylase, and chymotrypsin were measured in 15-min fractions. In addition, human lipase secretion was measured with an enzyme immunoassay, which does not crossreact with porcine lipase. Plasma cholecystokinin (CCK) was measured using a sensitive bioassay, which utilizes amylase release by isolated rat pancreatic acini. Perfusion of the duodenum with phenylalanine caused a statistically significant stimulation of enzyme secretion. This stimulation could be inhibited by high concentrations of pure trypsin. In contrast, application of porcine pancreatic extracts, which contained the equivalent activity of trypsin, caused further increases of lipase secretion when compared to phenylalanine alone.(ABSTRACT TRUNCATED AT 250 WORDS)     

Assessment of pancreatic enzyme secretory capacity by a modified Lundh test.

BACKGROUND: The Lundh test is a usual means of estimating the enzyme secretory capacity of the gland. During this procedure, however, a major proportion of the test meal is removed from the duodenum together with the gastric, duodenal, and pancreatic secretions and the bile. This study was undertaken to compare the pancreatic enzyme secretion induced by the Lundh procedure with that resulting from stimulation of the normal digestive process, by reinfusion of the aspirated duodenal juice. METHODS: Nine men (mean age: 46.7, range 42-55 yr) free from pancreatic disease were studied. Pancreatic secretion was measured via a multiple lumen tube by aspiration of the duodenal juice. After a basal period the Lundh test meal was placed in the stomach and the duodenal juice was completely aspirated. On a separate day, the procedure was repeated, but the aspirated duodenal juice was reinfused into the upper jejunum. RESULTS: In the first 30 min of the test period, the enzyme outputs were the same on both test days. In the 30-60-min period, the lipase output, and in the 75-90-min period, the amylase output was significantly lower during the Lundh test compared with the jejunal reinfusion test. The CCK levels were significantly above the basal level at 20 and 40 min, but the increase was significantly lower during the traditional Lundh test. No significant difference in gastrin release was observed during either the Lundh or the reinfusion test. CONCLUSIONS: In the traditional Lundh test, the trypsin secretory capacities of the gland are measured appropriately, but the lipase and amylase secretory capacity and the CCK release are not fully represented compared with the reinfusion test. An association between the lower CCK release and lipase amylase secretion is suggested.     

13C-Labeled Trioctanoin Breath Test for Exocrine Pancreatic Function Test in Patients after Pancreatoduodenectomy

To assess exocrine pancreatic function in patients before and after pancreatoduodenectomy (PD), we used the breath test, with nonradioactive ¹³C-labeled trioctanoin, in 14 patients before pancreatic resection because of localized pancreatic mass (preop-PD group), and in 13 patients who had undergone pancreatoduodenectomy more than 5 yr before (post-PD group). The results were compared with those of the secretin test, N-benzolyl-L-tyrosyl-p-amino benzoic acid (BT-PABA) test, and fecal chymotrypsin. Means ± SD and frequencies of low values of the recovery of the breath test were 42.0 ± 3.4%, 0/5 in the control; 24.2 ± 10.5%, 14/14 in the preop-PD group; and 18.6 ± 8.0, 13/13 in the post-PD group. The overall sensitivities in the preop- and post-PD groups were 100% for the recovery and 93% for the maximal mass ratio of the breath test, 89% for the secretin test, 67% for the BT-PABA test, and 64% for fecal chymotrypsin. The recovery of the breath test correlated significantly with the duodenal outputs of lipase, amylase, and chymotrypsin, and was not affected in patients with obstructive jaundice or with low D-xylose absorption. The breath test is as sensitive as the secretin test, more reliable than the conventional tubeless tests, and is available to follow up the exocrine pancreatic function before and after pancreatoduodenectomy.     

Fecal chymotroypsin: a study on its diagnostic value by comparison with the secretin-cholecystokinin test

Fecal chymotrypsin (CT) activities were determined in 149 randomly collected fecal specimens of 80 patients in whom the pancreatic function had been tested by a secretin-cholecystokinin test. There was a significant correlation between fecal CT activities and outputs of trypsin (r = 0.3451, p less than 0.01) and amylase (r = 0.3285, p less than 0.01) in duodenal juice. Fecal CT activities were normal in all patients who--based upon enzyme outputs in duodenal juice after stimulation with secretin and CCK/PZ--were classified as 'borderline cases', in most patients with 'low-normal' pancreatic function, and in a significant number of patients with established insufficiency of exocrine pancreas. On the other hand, fecal CT activities were abnormal in patients with severely impaired output of trypsin in duodenal juice, and only 7% of the fecal specimens from patients with established normal function of exocrine pancreas had abnormal low CT activities. It is concluded that the sensitivity of the fecal enzyme method is rather low as compared to the secretin-cholecystokinin test, but that fecal CT determinations give valuable diagnostic information in patients with more pronounced insufficiency of the exocrine pancreas.     

Agarose gel electrophoresis of duodenal juice in normal condition and in children with malabsorption.

Agarose gel electrophoresis (at pH 8.6) was used for qualitative determination of pancreatic enzymes in duodenal juice. The various enzymes were identified by staining techniques with specific chromogenic substrates, by quantitative determination of enzymes in eluates of gel slices, and by immunoelectrophoresis. The various protein bands corresponded to the following enzymes (from the anode to the cathode): chymotrypsin, trypsin, carboxypeptidase A, chymotrypsin, amylase (around the slit), lipase, elastase, and trypsin. The method was applied to a study of exocrine pancreatic function in 10 adults and 83 children suspected of having malabsorption. The duodenal juice, also analyzed for trypsin and amylase content, was collected in fasting condition and after a test meal of water. In patients with normal pancreatic function, all the enzyme bands were present and easy to recognize. In 87 patients carboxypeptidase A was present as two bands in 68 (80%), anodal trypsin as two bands in 39 (45%), and cathodal trypsin as two bands in 85 (97%). Electrophoresis of duodenal juice gave as much information from the fasting sample as after the test meal. Six children with pancreatic insufficiency (cystic fibrosis and Shwachmar's syndrome) had no or only faintly stained enzyme bands and a strongly stained albumin-containing band most anodally. The method is simple, rapid, and useful in routine work. The combination of this qualitative test with a quantitative one (e.g. trypsin determination) provides good information about exocrine pancreatic function.     

Assessment of pancreatic enzyme secretory capacity by a modified Lundh test

Summary Background. The Lundh test is a usual means of estimating the enzyme secretory capacity of the gland. During this procedure, however, a major proportion of the test meal is removed from the duodenum together with the gastric, duodenal, and pancreatic secretions and the bile. This study was undertaken to compare the pancreatic enzyme secretion induced by the Lundh procedure with that resulting from stimulation of the normal digestive process, by reinfusion of the aspirated duodenal juice. Methods. Nine men (mean age: 46.7, range 42–55 yr) free from pancreatic disease were studied. Pancreatic secretion was measured via a multiple lumen tube by aspiration of the duodenal juice. After a basal period the Lundh test meal was placed in the stomach and the duodenal juice was completely aspirated. On a separate day, the procedure was repeated, but the aspirated duodenal juice was reinfused into the upper jejunum. Results. In the first 30 min of the test period, the enzyme outputs were the same on both test days. In the 30–60-min period, the lipase output, and in the 75–90-min period, the amylase output was significantly lower during the Lundh test compared with the jejunal reinfusion test. The CCK levels were significantly above the basal level at 20 and 40 min, but the increase was significantly lower during the traditional Lundh test. No significant difference in gastrin release was observed during either the Lundh or the reinfusion test. Conclusions. In the traditional Lundh test, the trypsin secretory capacities of the gland are measured appropriately, but the lipase and amylase secretory capacity and the CCK release are not fully represented compared with the reinfusion test. An association between the lower CCK release and lipase amylase secretion is suggested.     

Duodenal lactoferrin in patients with chronic pancreatitis and gastrointestinal diseases

Lactoferrin (LF), chymotrypsin and lipase activity were measured in duodenal juice during pancreatic stimulation. Secretin (0.5 CU/kg/h) plus cerulein (75 ng/kg/h) were infused intravenously in 98 subjects: 33 patients without organic diseases (C), 40 patients affected by chronic pancreatitis (CP), and 25 patients with different gastrointestinal diseases (GID). LF was determined by means of a new noncompetitive immunoenzymatic assay with a sensitivity in the duodenal juice of 5 ng/ml. Duodenal LF concentrations were significantly higher in CP than in C or GID (p less than 0.001). LF was in a normal range in acute relapsing pancreatitis due to biliary stones or pancreas divisum. In the diagnosis of the chronic pancreatitis, LF/lipase ratios showed a specificity of 93% and a sensitivity of 95%. Our results show that LF immunoassay in duodenal juice is a sensitive and accurate assay to apply in pancreatic function tests involving duodenal content analysis.     

Effects of CCK-8 in combination with natural or synthetic secretin on amylase, lipase, trypsin, and chymotrypsin secretion in rats

In the present study, we examined the interaction between CCK-8 and natural or synthetic secretin on pancreatic enzyme secretion. On anaesthetized rats, a proximal duodenal segment was continuously perfused with saline and amylase, lipase, trypsin, and chymotrypsin were determined in the perfusate. Neither during iv saline nor during iv secretin (natural or synthetic) at doses of 0.01, 0.05, or 0.1 CU/kg/h, any of the four enzymes changed significantly from basal values over a period of 100 min. Iv CCK-8 at stepwise increasing doses of 5, 10, and 20 pmol/kg/h elicited a significant increase of all four enzymes at the medium dose, with a further increase of amylase and trypsin, but not lipase and chymotrypsin at 20 pmol/kg/h. The addition of secretin at all 3 doses potentiated CCK-induced trypsin output. The effects of natural secretin were more pronounced than those of the synthetic peptide. Secretin significantly increased amylase secretion over basal at the lowest dose of CCK-8 (5 pmol/kg/h) that by itself had no effect on amylase release. Only the higher doses of natural but not synthetic secretin augmented lipase secretion during the lowest dose of CCK-8. Both forms of secretin had no further stimulatory effect on CCK-induced chymotrypsin secretion. The present data demonstrate that, first, in rats a potentiation of CCK-8-induced enzyme secretion by low doses of secretin is different for the four enzymes, which suggests a differential regulatory action of these two intestinal hormones on pancreatic enzyme release. Second, the different effects of natural secretin may represent those of contaminants suggesting that only synthetic secretin should be employed in future studies of this peptide on pancreatic enzyme secretion.     

Alterations of exocrine pancreas in end-stage renal disease do they reflect a clinically relevant uremic pancreopathy?

Serum pancreatic enzyme behavior, exocrine function, and morphology of the pancreas were studied in 28 patients with end-stage renal disease undergoing regular hemodialysis, in order to better delineate and assess the clinical relevance of the pancreatic alterations that occur in these patients. Twenty-eight healthy subjects served as controls. Initial studies included serum amylase, isoamylase, and lipase assays; fecal chymotrypsin measurement; and abdominal ultrasonography. The amylase, lipase, and chymotrypsin determinations, as well as ultrasound examination, were repeated four years later. None of the patients had clinical evidence of pancreatic disease at entry into the study, but one had had previous attacks of pancreatitis and another developed mild acute pancreatitis one month after entry. Initial mean serum enzyme levels were significantly higher in patients than in controls (amylase, pancreatic isoamylase, and lipase,P<0.001; salivary isoamylaseP<0.05). Serum amylase was raised in 16/28 patients; pancreatic isoamylase in 15/28, and lipase in 7/28; these elevations were generally mild. Mean fecal chymotrypsin was significantly lower (P<0.001) in patients than in controls: abnormally low values were found in 9/28 patients. Amylase, lipase and chymotrypsin measurements repeated after four years showed no significant difference with respect to the first study. Ultrasonographic changes were rare and mild: one patient had a small cyst in the pancreas head, another, an increase in echogenicity of the gland not related to age; these findings were unchanged at repeat examination. The results demonstrate that the frequent elevations of serum pancreatic enzymes and the rare sonographic changes found in patients undergoing hemodialysis do not generally reflect a relevant pancreopathy. However, the finding of significantly decreased fecal chymotrypsin may indicate the presence of pancreatic dysfunction in end-stage renal disease.The preliminary results of this study were presented in Ulm (Germany) at the European Pancreatic Club Meeting October 11–14, 1992.This study was partially supported by the University and Scientific Technological and Research Ministry in 1993.