Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.26.9 (ribonuclease)
 6,589 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Intravenous infusion of synthetic secretin for periods up to 24 h in conscious rats was combined with in-vitro amino acid incorporation in isolated pancreatic lobules and high-resolution separation of individual enzyme proteins by two-dimensional isoelectric focusing and SDS gel electrophoresis. With this method persistent changes in the biosynthesis of ten enzyme and isoenzyme proteins can be studied as a result of prolonged secretin stimulation. Three major patterns of response were observed: progressive increases in the synthetic rates were found in six out of ten enzyme proteins with most pronounced changes in the synthetic rates of lipase (4.10-fold increase), two forms of proelastase (2.80-fold increase, respectively), the two acidic forms of trypsinogen and chymotrypsinogen (2.60- and 2.40-fold increase, respectively), and of ribonuclease (2.30-fold increase). Only moderate changes (1.30- to 1.90-fold increase) occurred in the synthetic rates of four isoenzymatic forms of procarboxypeptidase and the basic forms of chymotrypsinogen and trypsinogen, respectively. No absolute change in the rate of synthesis was observed in both forms of amylase. These data obtained after secretin stimulation differ significantly from previous results after caerulein stimulation, but it is not clear so far whether this is due to differential effects of the two second messengers released by each of the hormones on the level of transcription or translation.
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PMID:In-vivo stimulation of rat pancreatic acinar cells by infusion of secretin. II. Changes in individual rates of enzyme and isoenzyme biosynthesis. 241 53

Because of the location of the pancreas deep in the abdominal cavity, laboratory tests play a major role in the diagnosis of pancreatic diseases. Amylase and lipase determinations in serum are most frequently performed and they complement each other. However, false positive and false negative results are observed. In order to increase the sensitivity and specificity of diagnostic tests, urine amylase determinations, measurements of the CAmyl Ccreat ratio and amylase isoenzyme determinations are performed. The benefits of these procedures and their limitations will be discussed. The increased sensitivity and specificity of immunoreactive trypsin determinations and contributions of this test to the early diagnosis of pancreatic disease will be described. This test seems to have some usefulness in the early diagnosis of cancer, together with the secretin and pancreozymine-cholecystokinin test and the test for ribonuclease activity in serum.
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PMID:Enzyme measurements in the investigation of pancreatic diseases. 616 Aug 3

We have examined the secretogogue responsiveness and the pattern of secretory proteins produced by a transplantable rat pancreatic acinar cell tumor. Dispersed tumor cells were found to discharge secretory proteins in vitro when incubated with hormones that act on four different classes of receptors: carbamylcholine, caerulein, secretin-vasoactive intestinal peptide, and bombesin. With all hormones tested, maximal discharge from tumor cells was only about one-half that of control pancreatic lobules, but occurred at the same dose optima except for secretin, whose dose optimum was 10-fold higher. Biochemical analysis of secretory proteins discharged by the tumor cells was carried out by crossed immunoelectrophoresis and by two-dimensional isoelectric focusing-SDS polyacrylamide gel electrophoresis. To establish a baseline for comparison, secretory proteins from normal rat pancreas were identified according to enzymatic activity and correlated with migration position on two-dimensional gels. Our results indicate that a group of basic polypeptides including proelastase, basic trypsinogen, basic chymotrypsinogen, and ribonuclease, two out of three forms of procarboxypeptidase B, and the major lipase species were greatly reduced or absent in tumor cell secretion. In contrast, the amount of acidic chymotrypsinogen was notably increased compared with normal acinar cells. Although the acinar tumor cells are highly differentiated cytologically and express functional receptors for several classes of pancreatic secretagogues, they show quantitative and qualitative differences when compared with normal pancreas with regard to their production of secretory proteins.
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PMID:Biochemical analysis of secretory proteins synthesized by normal rat pancreas and by pancreatic acinar tumor cells. 618 2

Laboratory tests are the object of continuous interest in acute as well as chronic pancreatic disease. Enzymic assays play an important role, particularly in screening for pancreatic disease. The diagnostic contribution of amylase, isoamylases, immunoreactive trypsin and lactoferrin, ribonuclease and galactosyltransferase, as well as the problem of chronic nonpancreatic hyperamylasemia is reviewed. Functional methods detect a normal or abnormal function and in this sense the results should be interpreted. Present evaluation of the pancreozymin-secretin test, the Lundh test, fecal chymotrypsin, determination of stimulated chymotrypsin secretion by peroral synthetic substrates marked with 4-aminobenzoic acid, duodenal excretion of 75Se-methionine and plasma pancreatic polypeptide is given. Up to now, immunologic methods have not fulfilled the expectations in spite of considerable attention paid to them in recent years.
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PMID:[Developments in the laboratory diagnosis of diseases of the exocrine pancreas (author's transl)]. 702 8

Previous work from our laboratory has implicated hormone-induced plasma membrane movement (i.e., endo- and exocytosis) in water and electrolyte transport by the epithelial cells that line the ducts in the liver (i.e., cholangiocytes). To further explore the cellular mechanisms regulating ductal bile secretion, we infused somatostatin and/or secretin intravenously into rats 2 wk after either bile duct ligation (BDL), a procedure that induces selective proliferation of cholangiocytes, or sham surgery and measured bile flow and biliary constituents. We also determined the effect of somatostatin on basal and secretin-induced exocytosis by purified cholangiocytes isolated from rat liver after BDL. Finally, we studied the expression of the somatostatin receptor gene by both ribonuclease (RNase) protection and nuclear run-on assays using cDNA encoding for two subtypes of the somatostatin receptor gene (i.e., SSTR1 and SSTR2). In vivo, somatostatin infusion caused a dose-dependent bicarbonate-poor decrease (57% maximal decrease below baseline; P < 0.05) in bile flow in BDL but not in sham-operated rats; in contrast, secretin caused a dose-dependent bicarbonate-rich choleresis (228% maximal increase above baseline; P < 0.05) in BDL but not in sham-operated rats. Simultaneous or prior infusion of somatostatin inhibited the secretin-induced hypercholeresis in BDL rats. In vitro, somatostatin had no effect on basal exocytosis by cholangiocytes isolated from BDL rats; however, somatostatin inhitibed (88% maximal inhibition; P < 0.05) secretin-induced exocytosis by cholangiocytes in a dose-dependent fashion. In addition, somatostatin inhibited secretin-induced increases in levels of adenosine 3',5'-cyclic monophosphate (cAMP) in cholangiocytes isolated from BDL rats.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Somatostatin inhibits secretin-induced ductal hypercholeresis and exocytosis by cholangiocytes. 763 87