U.R. Fölsch

Role of cholecystokinin in the negative feedback control of pancreatic enzyme secretion in conscious rats

Using a specific radioimmunoassay for cholecystokinin (CCK) we have studied the relation between circulating CCK concentrations and the feedback regulation of pancreatic enzyme secretion in conscious rats. Recirculation of diverted bile-pancreatic juice into the duodenum or intraduodenal perfusion of trypsin during biliary-pancreatic juice diversion produced basal output of amylase and trypsin and low portal CCK levels (less than 10 pmol/L). Biliary-pancreatic juice diversion or inactivation of trypsin caused increased CCK concentrations (peak values 50-100 pmol/L) and enzyme outputs. During biliary-pancreatic juice diversion, infusion of the CCK receptor antagonist proglumide suppressed the enzyme response without altering the increase in CCK. Measurement of portal and peripheral CCK during biliary-pancreatic juice diversion yielded values of 131 +/- 37 and 32 +/- 5 pmol/L, respectively. The peripheral CCK levels corresponded to concentrations achieved during exogenous CCK-8 infusion which resulted in similar enzyme outputs. Gel chromatography of portal plasma during diversion of biliary-pancreatic juice revealed one peak of CCK corresponding to CCK-8, and a larger peak eluted between CCK-33 and CCK-8, probably representing CCK-22. Similar CCK components were found in water extracts of jejunal mucosa, whereas the acetic acid extracts mainly contained CCK-33/39. We conclude that the negative feedback regulation of pancreatic enzyme secretion in rats is mediated by the release of CCK from the intestine and that the major molecular form of CCK in plasma is probably CCK-22.

Enteral Long-Term Nutrition via Percutaneous Endoscopic Gastrostomy (PEG) in 210 Patients A Four-Year Prospective Study

After PEG placement at the Medical Department ofthe University Hospital in Kiel, 210 patients (mean age61.3 years; 137 men, 73 women) were prospectivelyfollowed-up for 133 ± 181 days. Close-meshed evaluations of the development of nutritionalstatus, long-term outcome, complications, subjectiveacceptability, patient care after discharge from thehospital, survival, and nutritional long-term problems were performed. The PEG procedure (duration13.3 ± 4.2 min) was carried out for neurological(42%), ear-nose-throat (28%), and internal medical (30%)indications. Procedure-related mortality was 0%, while altogether 3.8% severe and 20.0% mildcomplications were observed. Body weight decreased by amean of 11.4 ± 1.5 kg in the three months beforeand increased by 3.5 ± 1.7 kg one year after PEGplacement with no significant differences betweenmalignant or benign underlying diseases. Individualsubjective acceptability was excellent in 83%,sufficient in 15%, and poor in 2% of patients only.One-year survival rate was 34.3%. The various results of thepresent prospective study demonstrate that long-termenteral feeding via PEG is a safe, effective,easy-topractice, and highly acceptable method withexcellent long-term results and distinct improvement ofnutritional status. Individual decisions for PEGplacement should be considered much earlier and morefrequently in appropriate patients.

Influence of Repeated Administration of Cholecystokinin and Secretin on the Pancreas of the Rat

Repeated injections of cholecystokinin (CCK) during a period of up to 3 weeks significantly increased the weight of the pancreas in rats. This was associated with an increase in the amount of protein per unit weight of DNA, suggesting hypertrophy of the acinar cells, and with increase in the total amount of pancreatic DNA, indicating additional hyperplasia of the gland. CCK administration also increased the pancreatic content of amylase and trypsin, but the content of lipase remained unchanged. The rate of secretion of the two enzymes increased in the CCK-treated rats, although it appeared that the functional capacity of the individual pancreatic acinar cells was not increased. CCK injections had no effect on the insulin content of the pancreas or on the composition of the partoid glands. Repeated injections of secretin in the doses used in this study had no effect on the pancreas.

Dietary polyamines are essential luminal growth factors for small intestinal and colonic mucosal growth and development

Background Polyamines are essential for cell growth. Dietary and probably gut bacterial derived polyamines contribute significantly to the polyamine body pool. Aims To evaluate the influence of dietary, luminal polyamines on growth and development of different gastrointestinal organs in normally growing rats. Methods Male suckling Wistar rats were randomly allocated to four treatment groups: polyamine deficient diet (PDD); PDD plus antibiotics (neomycin 2 g/kg and metronidazole 34 mg/kg); PDD plus polyamine supplementation at normal concentrations; or normal standard laboratory chow. After a six month feeding period 7–10 animals/group were sacrificed. Results No differences in body weight gain, food consumption, or general behaviour could be observed between the four groups of animals. Feeding of PDD alone or PDD plus antibiotics resulted in a highly significant decrease in organ weight, protein content, and DNA content in small intestinal and colonic mucosa whereas no alterations were found in the liver. Conclusions Long term feeding of polyamine deficient diets resulted in a significant hypoplasia of small intestinal and colonic mucosa. Dietary, luminal polyamines are important local factors for growth and the development of small intestinal and colonic mucosa.

Comparative Clinical Evaluation of the 13C-Mixed Triglyceride Breath Test as an Indirect Pancreatic Function Test

BACKGROUNDnBreath tests using stable isotopes of carbon or hydrogen are increasingly becoming established for the evaluation of various gastrointestinal functions, including measurement of exocrine pancreatic insufficiency. We wanted to evaluate the clinical relevance of the non-invasive, non-radioactive 13C-mixed triglyceride breath test in comparison with the secretin-caerulein test as the gold standard of pancreatic function testing and with faecal chymotrypsin and elastase 1 in patients with mild and severe exocrine pancreatic insufficiency.nnnMETHODSnThe secretin-caerulein test, faecal fat analysis, 13C-mixed triglyceride breath test, faecal elastase 1, and chymotrypsin and various morphologic investigations were done in 26 patients with mild (n = 13) or severe (n = 13) exocrine pancreatic insufficiency and 25 patients with gastrointestinal diseases of non-pancreatic origin. Twenty-seven healthy volunteers served as normal controls. After a 12-h fast 200 mg mixed triglyceride (1,3-distearyl,2(carboxyl-13C)octanoyl glycerol) were orally administered with a test meal, and breath samples were taken before and at 30-min intervals for 5 h thereafter, and the increase in 13C/12C isotopic ratio in breath was analysed by mass spectrometry. Various modifications of the test procedure were investigated.nnnRESULTSnSpecificity for impaired pancreatic function was higher for faecal elastase (90%) and equal for faecal chymotrypsin (82%) as compared with the various variables of the 13C-mixed triglyceride breath test (69-85%). The sensitivity of the 13C-mixed triglyceride breath test for total and separately for mild and severe exocrine pancreatic insufficiency was higher (total, 69-81%) than that of faecal chymotrypsin (total, 56%) but lower than faecal elastase (total, 92%).nnnCONCLUSIONnThe 13C-mixed triglyceride breath test very sensitively reflects severe exocrine pancreatic insufficiency (steatorrhoea) but has limited sensitivity for the detection of mild cases. With regard to the higher sensitivity and specificity, the higher practicability, and the much lower cost, determination of faecal elastase 1 concentrations is superior to the 13C-mixed triglyceride breath test and therefore remains the most reliable indirect pancreatic function test available today.

Effect of Short- and Long-Term Feeding of Omeprazole on Rat Gastric Endocrine Cells

Rats were tube-fed with omeprazole (40 mumol/kg body weight twice daily) for 30 and 60 days. As a result, fasting plasma gastrin levels were significantly elevated, while plasma somatostatin levels remained normal. Gastrin concentrations in the antral mucosa were unchanged after 30 days, but significantly elevated after 60 days. The relative stomach weight and the area of the antral and oxyntic mucosa increased significantly; however, the oxyntic mucosa thickness and the volume density of the parietal cells did not increase. Highly significant changes occurred in the endocrine cells of the antrum and corpus. The volume density of the argyrophilic (Grimelius technique) cells of the oxyntic mucosa increased time-dependently, and so did the volume density of the antral G cells, while the volume density of the antral D cells decreased. This resulted in a remarkable increase in the G/D cell ratio. All functional and morphological changes are reversed 42 days after omeprazole feeding for 60 days. The findings in the endocrine cells of the antral mucosa are explained by the omeprazole-induced permanent elevation of the intragastric pH and in the endocrine cells of the oxyntic mucosa by the following hypergastrinaemia.

Reversed-phase liquid chromatographic separation and simultaneous fluorimetric detection of polyamines and their monoacetyl derivatives in human and animal urine, serum and tissue samples: An improved, rapid and sensitive method for routine application

A highly sensitive and precise method for the determination of the polyamines putrescine, cadaverine, spermidine and spermine and all their monoacetyl derivatives in a single analysis in human and animal urine, serum and tissue samples is described. For polyamine separation, an ion-pairing reversed-phase high-performance liquid chromatographic (HPLC) method is used, followed by post-column derivatization with o-phthalaldehyde and consecutive fluorescence detection. Urine and serum samples are purified with a Bond Elut silica cartridge. The detection limit for polyamines is 0.5-1.0 pmol and excellent linearity is achieved in the range from 3 pmol up to more than 10 nmol. The influence of some modifications of different analytical steps such as the temperature of the HPLC column and the derivatization reaction coil and the o-phthalaldehyde flow-rate is described. Quality control data and measurements of the reproducibility of the method are presented. In order to establish a rapid analytical method for easy routine use, all steps for preparation and quantitative analysis are minimized. This method was applied to the determination of total polyamines in human urine and serum hydrolysate and of free and acetylated polyamines in human urine and pancreatic tissue of the rat. Values for normal polyamine concentrations in the urine and serum of fifteen male and fifteen female healthy volunteers and in the pancreas of ten normal rats are presented.

Polyamines in colorectal cancer. Evaluation of polyamine concentrations in the colon tissue, serum, and urine of 50 patients with colorectal cancer

Total, free, and acetylated polyamine concentrations were measured simultaneously in colon tissue, serum, and urine of 50 patients with histologically proven colorectal cancer, 40 patients with nonmalignant gastrointestinal diseases, and 30 healthy volunteers. Compared with histologically unaffected colon tissue, concentrations were significantly (P < 0.001) higher for putrescine, elevated for cadaverine, and nearly identical for spermidine and spermine in colon carcinoma, whereas N1‐acetylated and N8‐acetylated spermidine were detectable in cancer tissue only. Serum and urine concentrations of all polyamines except total cadaverine and spermine in serum and free spermine in urine were significantly elevated compared with healthy controls and highest sensitivity for colon cancer was found for total spermidine (89.15%) in serum and acetylputrescine (84.5%), total putrescine (84.0%), N1‐acetylspermidine (79.3%), and total spermidine (92.1%) in urine. However, nonmalignant gastrointestinal diseases partly showed similar elevations which resulted in a low specificity for polyamines in colorectal cancer. Therefore, polyamines are of little value only as diagnostic markers in colorectal carcinoma. Since polyamine concentrations in serum and urine normalized in patients after curative operation while they were further elevated in patients with proven tumor relapse or metastases, these substances might play a clinical role in predicting therapeutic success or indicating relapse of the tumor. Although a significant dependency of polyamine concentrations in serum or urine to Dukes classification, tumor localization, CEA, CA 19‐9, or CA 125 did not exist, a significant linear correlation was found for tumor size.

Effect of somatostatin analogue (SMS 201-995, Sandostatin) on pancreatic secretion in humans.

The effect of the long-acting somatostatin analogue SMS 201-995 on exocrine pancreatic function and hormone release was investigated in a double-blind, placebo-controlled study in healthy subjects. SMS 201-995 was administered subcutaneously at a dose of 25 micrograms twice daily, and all tests were performed 30 minutes after the morning injection. Pancreatic enzyme secretion, gall bladder contraction, and cholecystokinin response after a Lundh meal were completely inhibited by SMS, while pancreatic enzyme secretion elicited by intravenous injection of secretin and pancreozymin was suppressed by 80 percent. The inhibitory effect of SMS on endogenous cholecystokinin release was fully operative on the sixth day of injection treatment, whereas the inhibitory effect on exogenous cholecystokinin injection significantly decreased after SMS administration for seven days, indicating desensitization of the end organ by somatostatin. The release of pancreatic polypeptide by a solid test meal is abolished by administration of 25 micrograms of SMS, the release of gastric inhibitory polypeptide is nearly completely suppressed, the response of insulin and C-peptide are significantly lowered, and the gastrin response is only slightly reduced.

Effect of a Soybean Diet on Enzyme Content and Ultrastructure of the Rat Exocrine Pancreas

The enzyme content and the ultrastructure of the rat exocrine pancreas were studied after feeding a normal diet or diets containing raw (RSF) or heat-inactivated (HSF) soybean flour for 20 days. The w