Administration of two antagonists of the cholecystokinin(B)/gastrin receptor does not totally inhibit the pancreatic response to a meal in the pig.

Introduction And Aims: The role of the cholecystokinin B (CCK(B))/gastrin receptor in the pancreatic response to a standard meal was investigated in the pig.

Methodology: Twenty-four pigs were prepared surgically for the collection of the pancreatic juice and an intravenous perfusion. On experimental days, the pigs were perfused with one of two CCK(B)antagonists (L-365,260 or PD 135156) or the vehicle for 2 hours.

Cholesterol crystallization in gall-bladder bile of pigs given cholesterol-beta-cyclodextrin-enriched diets with either casein or soyabean concentrate as protein sources.

Cholesterol precipitation from supersaturated bile is the earliest and determinant step in the formation of cholesterol gallstones, which is thought to be diet-dependent. Bile composition, appearance and growth of cholesterol crystals were studied in fresh gall-bladder biles from pigs adapted to four different protein-containing diets over 3 weeks: 160 g dietary protein/kg as casein (C16; n 6), or as soyabean-protein concentrate (S16; n 6), or a mixture of both protein sources (casein-soyabean protein, 70:30, w/w) (CS16; n 6), or 320 g of the mixed protein/kg (CS32; n 6). Moreover, all four diets contained 3 g cholesterol/kg and 50 g beta-cyclodextrin/kg as modifiers of bile composition towards cholesterol pro-crystallization.

Effect of beta-cyclodextrin dietary supplementation on biliary proteins and their resulting cholesterol nucleating activity in pigs.

We explored the possibility that the biliary protein fraction may support part of the variation in the nucleating activity previously measured in gallbladder biles of pigs. Eighteen gallbladder aspirates freshly obtained from three dietary groups (0, 5, or 10% beta-cyclodextrin) of six pigs were chromatographed to purify their total protein fraction. Proteins were quantified, and analysed through electrophoresis and immunoblotting or enzyme-linked immunosorbent assay for albumin, and five putative effectors of cholesterol crystallisation, mucins, immunoglobulin A, 130 kDa, apolipoprotein A-I, and anionic polypeptide fraction.

Effect of bombesin at low doses on the secretion of the exocrine pancreas and on plasma gastrin concentration in the conscious pig.

We investigated the role of low-doses of bombesin in the regulation of exocrine secretion in the pancreas of the conscious pig. In ten growing castrated male Large White pigs, bombesin was infused intravenously for 1 h at doses of 0 to 500 pmol/kg/h under a stimulation of secretin (36 pmol/kg/h). In six pigs, bombesin (50 pmol/kg/h) was administered alone for 2 h and its effect on pancreatic secretion was compared to that of an infusion of secretin.

Physiological effects of a pea protein isolate in gnotobiotic rats: comparison with a soybean isolate and meat.

Pea proteins have been considered for the introduction into the human diet only recently. This protein source was tested on nutritional and digestive parameters in heteroxenic male Fischer rats inoculated with a human faecal microflora from a methane producer. Compared to soybean proteins, pea proteins have similar effects on the rat's endogenous and bacterial digestive patterns.

Inducing cholesterol precipitation from pig bile with beta-cyclodextrin and cholesterol dietary supplementation.

Background/methods: In this study, pigs fed for 3 weeks a well-balanced semi-purified diet enriched with 0.3% cholesterol and 0, 5 or 10% beta-cyclodextrin were proposed as new animal donors of gallbladder bile exhibiting different rates of cholesterol crystallization, in order to gain insight into the early mechanisms underlying cholesterol precipitation in vivo. The appearance and growth of cholesterol crystals were monitored in the incubated freshly collected gallbladder biles through light microscopy and concomitant time-sequential determination of crystallized cholesterol concentration, and interpreted in terms of the composition of the bile.

Pharmacological and biochemical evidence for the simultaneous expression of CCKB/gastrin and CCKA receptors in the pig pancreas.

1. In the pig, the secretory response of the pancreas is not inhibited by the antagonist MK329 suggesting that cholecystokininA (CCKA) receptors are not involved. 2.

Hypocholesterolemic action of beta-cyclodextrin and its effects on cholesterol metabolism in pigs fed a cholesterol-enriched diet.

To examine the effects of beta-cyclodextrin (BCD), a non-absorbable carbohydrate, on lipid metabolism, growing pigs were fed a 0.3% cholesterol-enriched diet for 4 weeks or this diet containing 5% or 10% BCD. Pigs fed a basal diet without added cholesterol or BCD were used as controls.

Pig pancreatic acinar cells possess predominantly the CCK-B receptor subtype.

Studies performed on pig indicated that its pancreas was insensitive to the gastrointestinal hormone cholecystokinin (CCK) and suggested that its secretions were rather under the control of the neurotransmitter acetylcholine. This study was performed to determine reasons for this insensitivity by comparing secretory responses to different secretagogues and establishing the dominant CCK receptor type. Pancreatic acini prepared from weaned piglets were evaluated for their sensitivity to carbamylcholine (Cch), caerulein, JMV-180, and secretin.

Influence of caecal microflora and of two dietary protein levels on the adaptation of the exocrine pancreas: comparative study in germ-free and conventional rats.

Dietary proteins are degraded by both endogenous enzymes and the caecal microflora. In conventional rats the enzyme content of the pancreas depends on the amount of dietary protein. The influence of the caecal microflora on this process is unknown.

Kinetics of amino acid and glucose absorption following pancreatic diversion in the pig.

An experiment was conducted in the pig to determine the consequences of deprivation of exocrine pancreatic secretion on the composition and quantity of nutrients absorbed after intake of a balanced diet. Five growing pigs (53.8 kg body weight) were fitted with permanent catheters in the portal vein and the carotid artery and with an electromagnetic flow probe around the portal vein to measure the exchanges between the blood and the intestinal lumen.

Role of CCK in the regulation of secretion and adaptation in the pig pancreas.

The effect of cholecystokinin (CCK) on the pancreas was investigated in the pig in two experiments. Fifteen pigs were fed a diet containing 17 or 48% protein with or without MK329 (4.5 mg per meal).

Influence of bile salt molecular species on cholesterol crystallization from supersaturated model biles.

Time-sequential enzymatic determination of cholesterol (CH) crystals harvested by ultrafiltration, and concomitant polarizing light microscopy observations corroborated the striking importance of the bile salts (BS) species in determining CH crystals formation rate from supersaturated model biles incubated in vitro. The more hydrophilic tauroursodeoxycholate, taurohyocholate, glycohyocholate, taurohyodeoxycholate, glycohyodeoxycholate and glyco-3 alpha, hydroxy-6 oxo-5 beta-cholanate inhibited CH precipitation through the formation of a stabilized liquid-crystalline phase. In contrast, in all hydrophobic systems (taurine (T) and glycine (G) conjugates of cholate (C), deoxycholate (DC) and chenodeoxycholate (CDC)), CH crystals precipitated with time.

Evidence for an apical, nonregulated protein secretion in pig exocrine pancreas.

Secretory proteins are segregated into two pathways out of the trans-Golgi network of regulated secretory cells. To identify proteins specifically secreted by pathways other than the one leading to zymogen granule exocytosis in the exocrine pancreas, conscious permanently cannulated pigs were perfused with atropine to inhibit the regulated fusion of granules. Atropine almost totally inhibited the protein secretion after 1 h of perfusion.

Early adaptation of pancreas to a protein-enriched diet: role of cholecystokinin and gastrin-releasing peptide.

Feeding rats a diet containing high levels of protein (as casein) increases the secretion and biosynthesis of pancreatic serine proteases. Cholecystokinin (CCK) presumably plays a role in this process although other GI peptides such as the gastrin-releasing peptide (GRP) may be involved. In this article, we describe the kinetics of pancreatic adaptation to a diet containing 45% protein as soybean and fish.

Modulation of pancreatic secretion by capsaicin-sensitive sensory neurons in the rat.

The purpose of this work was to study whether stimulation or destruction of sensory afferents can modulate pancreatic secretion. The neurotoxin capsaicin is specific for a subpopulation of small diameter primary afferent neurons. Small doses of capsaicin were administered to anesthetized rats as intraduodenal or intragastric bolus injections to stimulate digestive sensory fibers, and pancreatic secretory response was measured.

Effects of caseinomacropeptide (CMP) on digestion regulation.

Caseinomacropeptide (CMP) is a 64-amino-acid-residue peptide which is released from kappa-casein by gastric proteinases. This review sums up the knowledge concerning its effects on the digestive function. Part 1 recalls the origin and heterogeneity of CMP.

Trypsin-dependent production of an antibacterial substance by a human Peptostreptococcus strain in gnotobiotic rats and in vitro.

An antibacterial substance appeared within 1 day in feces of gnotobiotic rats harboring a human intestinal Peptostreptococcus strain. It disappeared when the rat bile-pancreatic duct was ligatured or when the rats ingested a trypsin inhibitor. Anaerobic cultures of the Peptostreptococcus strain in a medium supplemented with trypsin also exhibited an antibacterial activity, which was also inhibited by the trypsin inhibitor.

Impact of exocrine pancreatic adaptation on in vitro protein digestibility.

An in vitro enzymic method was used to study the kinetics of digestion of casein and rapeseed proteins. After a predigestion step with pepsin (EC 3.4.

Exogenous and endogenous contributions to nitrogen fluxes in the digestive tract of pigs fed a casein diet. III. Recycling of endogenous nitrogen.

The aim of the present study was to measure the incorporation of infused 15N in blood fractions, urine, digesta, faeces and in the exocrine pancreatic and biliary secretions, in order to estimate the endogenous part of nitrogen in the ileal digesta and in the faeces of pigs fed a casein diet and to calculate the total endogenous nitrogen secretion as well as its recycling in the digestive tract. For 8 d 11 Large White female pigs (50.1 +/- 1.

[Endo-surgical dissection of the upper urinary tract through the retroperitoneal and transperitoneal route: an experimental study with pigs and cadavers].

In order to define the best method for endosurgical dissection of the upper urinary tract, an experimental study comparing the retroperitoneal and transperitoneal approaches was performed. Between September 1991 and February 1992, 15 female pigs and 8 human cadavres underwent endosurgical dissection of the upper urinary tract. The retroperitoneal approach was used in 8 pigs and 5 cadavres.

Effects of diets containing casein and rapeseed on enzyme secretion from the exocrine pancreas in the pig.

The effect of dietary protein on enzyme activity of pancreatic juice was studied in ten growing, castrated, Large White male pigs. Animals, fitted with permanent cannulas in the pancreatic duct and in the duodenum, were divided into two groups receiving either casein or rapeseed concentrate as a protein source. After a 15 d adaptation period to the experimental diet, the volume of pancreatic secretion was significantly higher, whereas the protein concentration was lower in the casein group compared with the rapeseed group.

Ion-pair high-performance liquid chromatography of bile salt conjugates: application to pig bile.

The high-performance liquid chromatographic separation and quantitation of conjugated bile salts from pig bile is reported. Synthetic standards and bile samples were chromatographed on a C18 reversed phase column using acetonitrile/water/tetrabutyl ammonium phosphate as an isocratic mobile phase at a flow rate of 1 mL/min. Detection of the ion-pairs was at 214 nm.