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Advances in Medical Sciences 2008Benign pancreatic hyperenzymemia is a newly identified syndrome characterized by an abnormal increase in serum pancreatic enzymes in the absence of pancreatic disease.... (Review)
Review
Benign pancreatic hyperenzymemia is a newly identified syndrome characterized by an abnormal increase in serum pancreatic enzymes in the absence of pancreatic disease. The hyperenzymemia can occur sporadically or in a familial form, and all of the pancreatic enzymes show elevations. Although the condition is persistent, the enzyme elevations fluctuate considerably, even temporarily returning to normal levels at times. In this review the main characteristics of this syndrome are described.
Topics: Acute Disease; Amylases; Humans; Lipase; Pancreas; Pancreatic Diseases
PubMed: 18650145
DOI: 10.2478/v10039-008-0027-7 -
European Journal of Cell Biology Feb 1991We have measured the rate of secretion in vitro of individual rat exocrine pancreatic enzymes and proenzymes from cells in pancreatic lobules of control animals and...
We have measured the rate of secretion in vitro of individual rat exocrine pancreatic enzymes and proenzymes from cells in pancreatic lobules of control animals and animals subjected to 24 h optimal hormonal prestimulation with cerulein, in vivo. With the controls secreted proteins were first detectable at 20 to 25 min of chase after a 5-min pulse label, and the amount of total secretion increased slowly thereafter. With stimulated lobules secretion was first detectable at 10 to 15 min postpulse. Comparison of the rates of secretion from control and experimental lobules showed that 24 h prestimulation in vivo resulted in a fivefold increase in the rate of secretion. Measurement of the rates of secretion of the individual enzymes and proenzymes showed that they were all increased to the same extent. In both situations the serine endoproteases, proelastase 2, chymotrypsinogen 1, and trypsinogen 1 and 2, were the most rapidly secreted proteins, while amylase, the procarboxypeptidases and prophospholipase A2 were amongst the slowest. The difference in the rates of secretion of proelastase 2 and prophospholipase A2, the two extremes, was three-fold before and after prestimulation, and their halftimes of secretion from the hormonally prestimulated lobules were 34 min and 190 min, respectively. Both electron microscopic autoradiography and immunocytochemistry showed that in the hormonally prestimulated cells the secreted proenzymes and enzymes followed the normal regulated exocytotic pathway and were transported between the Golgi apparatus and the apical plasma membrane in dense cored secretory granules.
Topics: Animals; Biological Transport; Ceruletide; Electrophoresis, Gel, Two-Dimensional; Enzyme Precursors; Enzymes; Immunohistochemistry; Kinetics; Male; Microscopy, Electron; Pancreas; Rats; Rats, Inbred Strains
PubMed: 2032550
DOI: No ID Found -
Developmental Biology Nov 1972
Topics: Amylases; Animals; Carboxypeptidases; Cell Differentiation; Chick Embryo; Chymotrypsin; Endonucleases; Endoplasmic Reticulum; Hydrocortisone; Pancreas; Stimulation, Chemical
PubMed: 4652270
DOI: 10.1016/0012-1606(72)90069-3 -
The Proceedings of the Nutrition Society Mar 1996
Review
Topics: Amino Acid Sequence; Animals; Dietary Fats; Digestion; Enzyme Activation; Humans; Hydrolases; Lipase; Molecular Sequence Data; Pancreas; Stomach
PubMed: 8832779
DOI: 10.1079/pns19960008 -
The Journal of Biological Chemistry Apr 1975An in vitro system of guinea pig pancreatic lobules convenient for the study of secretory processes is described in this paper. In this system: (a) the over-all...
An in vitro system of guinea pig pancreatic lobules convenient for the study of secretory processes is described in this paper. In this system: (a) the over-all glandular architecture of the tissue is preserved: lobules remain morphologically intact through 5 hours; (b) amylase discharge from unstimulated lobules is low (similar to 4%/hour) and linear over the 5 hours tested; (c) response to carbamylcholine chloride (10-5 M) is energy-dependent, rapid, and extensive (92% discharge of amylase by 5 hours); (d) initial rates of discharge remain stable over the first 3 hours; and (e) no autoactivation of zymogens occurs in incubation medium or tissue. The activation of four zymogens, i.e. chymotrypsinogen, trypsinogen, and procarboxypeptidases A and B, was studied using the following criteria for optimal activation: (a) maximal activation attainable under experimental conditions; (b) stability at the level of maximal activation; and (c) linear relationship between amounts of protein activated and enzyme activity elicited by activation. The concentration of activators (trypsin or enterokinase) and secretory protein, the presence or agents (bovine plasma albumin or Triton X-100) which minimize adsorptive losses of secretory protein on glass or plastic surfaces, and the temperature at which activation is carried out were found to be critical and different for each of the zymogens tested. The kinetics of the appearance of three enzyme activities (amylase, lipase, and ribonuclease) and four potential proteolytic activities (chymotrypsinogen, trypsinogen, and procarboxypeptidases A and B) into the incubation medium was studied under different conditions; i.e. rest and stimulation with various secretogogues (carbamylcholine chloride, caerulein, and pancreozymin). All seven activities estimated to represent similar to 75% of the secretory protein output of the exocrine pancreas were discharged in synchrony and in constant proportions and were released from the tissue to the same extent under each experimental condition investigated.
Topics: Animals; Carboxypeptidases; Chymotrypsinogen; Endopeptidases; Enzyme Precursors; Enzymes; Guinea Pigs; Kinetics; Microscopy, Electron; Pancreas; Protein Kinases; Time Factors; Trypsin; Trypsinogen
PubMed: 1123325
DOI: No ID Found -
Clinical Physiology and Functional... Sep 2002It has been shown previously that medium chain triglycerides (MCT) do not affect gallbladder emptying and cholecystokinin (CCK) release. The effect of MCT on exocrine... (Clinical Trial)
Clinical Trial
It has been shown previously that medium chain triglycerides (MCT) do not affect gallbladder emptying and cholecystokinin (CCK) release. The effect of MCT on exocrine pancreas secretion in humans is unknown. We have compared the effect of enteral administration of MCT versus long chain triglycerides (LCT) on exocrine pancreatic secretion. Eight healthy subjects (three female, five male; mean age 22 +/- 1.9 years) participated in two experiments, performed in random order. Duodenal contents, obtained by aspiration, were used to calculated the output of pancreatic enzymes and bilirubin. An equicaloric amount of either MCT or LCT (2 kcal min-1) oil was continuously administered in the proximal jejunum for 2 h. Gallbladder volume was measured by ultrasonography and blood samples were drawn for determination of CCK. The experiments consisted of 1 h basal secretion, 2 h of continuous oil administration and 1 h poststimulation. During the LCT feeding the pancreatic enzyme secretion, bilirubin output, gallbladder emptying and CCK release increased significantly (P < 0.05) over basal levels. MCT had no effect on pancreatic enzyme secretion nor gallbladder emptying or CCK release. We conclude that enteral administration of MCT in the proximal jejunum does not stimulate exocrine pancreatic secretion nor gallbladder contraction or CCK release, in contrast to an equicaloric amount of LCT.
Topics: Adolescent; Adult; Amylases; Bilirubin; Cholecystokinin; Duodenum; Energy Intake; Female; Gallbladder Emptying; Humans; Jejunum; Lipase; Male; Pancreas; Random Allocation; Triglycerides
PubMed: 12487002
DOI: 10.1046/j.1475-097x.2002.00435.x -
The American Journal of Physiology Jun 1996Okadaic acid, a serine/threonine phosphatase inhibitor, has been shown to inhibit rat pancreatic enzyme secretion by interference with late processes in...
Okadaic acid, a serine/threonine phosphatase inhibitor, has been shown to inhibit rat pancreatic enzyme secretion by interference with late processes in stimulus-secretion coupling. To further characterize its action, we studied the effect of okadaic acid on secretion of newly synthesized proteins, protein synthesis, and cellular ultrastructure in pancreatic lobules derived from rats stimulated in vivo by feeding the synthetic proteinase inhibitor FOY-305. Okadaic acid completely blocked protein secretion at concentrations that inhibit the Ca2+/calmodulin-dependent protein phosphatase 2b, calcineurin. Protein synthesis was abolished at 10(-6) mol/l and reduced by 60% at 5 x 10(-7) mol/l okadaic acid. Pancreatic lobules exposed to 5 x 10(-7) mol/l okadaic acid for 20 min fully restored their secretory capacity on removal of the drug; whereas, after a preincubation with okadaic acid for > 40 min, protein secretion remained impaired during the recovery period. Electron microscopic examination of pancreatic acinar cells treated with 5 x 10(-7) mol/l okadaic acid revealed a dilated Golgi complex after 15 and 30 min and a subsequent fragmentation of Golgi cisternae into clouds of small uniform vesicles after 60 min. Reassembly of Golgi stacks occurred after a 60-min recovery without okadaic acid. These data indicate that serine/threonine phosphatases play an important role not only in the regulation of pancreatic enzyme synthesis and exocytosis but also are crucial for the maintenance of normal Golgi architecture and function in the exocrine rat pancreas. These effects are probably not exclusively mediated via type 2b calcineurin-like protein phosphatases.
Topics: Animals; Cholecystokinin; Enzymes; Esters; Ethers, Cyclic; Gabexate; Golgi Apparatus; Guanidines; Male; Microscopy, Electron; Okadaic Acid; Pancreas; Protease Inhibitors; Protein Biosynthesis; Rats; Rats, Wistar
PubMed: 8764200
DOI: 10.1152/ajpgi.1996.270.6.G939 -
Acta Biochimica Polonica 1981The model of the multiple attack mechanism has been proposed for the enzyme consisting of two hypothetical subunits or domains identical in structure and function. The...
The model of the multiple attack mechanism has been proposed for the enzyme consisting of two hypothetical subunits or domains identical in structure and function. The theoretical coefficients of multiple attack: effectiveness and average number of unitary movements, have been computed for such a dual-site model of pancreatic alpha-amylase. Those coefficients affect the values of maximum velocity and Michaelis constant, respectively. Two possible manners of the subunit coupling were considered: symmetric and sequential. The dual-site model with a symmetric type of coupling appeared to be kinetically indistinguishable from the single-site model.
Topics: Amylases; Animals; Binding Sites; Kinetics; Models, Chemical; Pancreas; Swine; alpha-Amylases
PubMed: 6172918
DOI: No ID Found -
The American Journal of Physiology Oct 1980Incubating dispersed acini from guinea pig pancreas with cholecystokinin and then washing the cells to remove cholecystokinin reduced the subsequent stimulation of...
Incubating dispersed acini from guinea pig pancreas with cholecystokinin and then washing the cells to remove cholecystokinin reduced the subsequent stimulation of amylase secretion caused by pancreatic secretagogues, whose actions are mediated by release of cellular calcium (i.e., cholecystokinin, carbamylcholine, bombesin, litorin, physalaemin, and A23187), but did not alter the stimulation caused by secretagogues whose actions are mediated by cAMP (i.e., vasoactive intestinal peptide and secretin). This cholecystokinin-induced desensitization was reversible, and the onset of the process as well as its reversal were time- and temperature-dependent changes. The concentrations of cholecystokinin required to cause desensitization were greater than those required to cause maximal stimulation of amylase secretion, and this finding suggests that the submaximal stimulation of enzyme secretion seen with supramaximal concentrations of cholecystokinin may be caused by cholecystokinin-induced desensitization.
Topics: Amylases; Animals; Cholecystokinin; Dose-Response Relationship, Drug; Guinea Pigs; Male; Pancreas; Secretory Rate
PubMed: 6158873
DOI: 10.1152/ajpgi.1980.239.4.G272 -
Pancreas 1988
Review
Topics: Age Factors; Animals; Enzymes; Humans; Models, Biological; Pancreas
PubMed: 3290896
DOI: 10.1097/00006676-198805000-00017