Ami Takatera | PubMed Health

PubMed2002

Relation between morphologic changes in the main pancreatic duct and exocrine pancreatic function after a secretin test.

INTRODUCTION: Because pancreatic exocrine function testing methods are problematic, both imaging and functional tests are important in the diagnosis of chronic pancreatitis. AIM: To evaluate the usefulness of ultrasonographic monitoring of the main pancreatic duct after a secretin test. METHODOLOGY: A total of 70 subjects (30 control subjects, 26 patients with probable chronic pancreatitis, and 14 patients with definite chronic pancreatitis) were selected. The main pancreatic duct diameters were measured serially after an injection of secretin (100 IU/body). The relation between the magnitude of the duct dilation and exocrine pancreatic function on the secretin test was evaluated. RESULTS: The main pancreatic duct dilated immediately after a bolus injection of secretin, showed a peak after 2-5 minutes, and recovered gradually. The response curve of the definite group had a flatter pattern than that of the other groups. For the maximal to basal duct diameter ratio, statistically significant differences were found between the control and definite groups and between the control and probable groups. In addition, the ratio correlated significantly with the maximal bicarbonate concentration and secretory volume on the secretin test. CONCLUSIONS: The results of the current study indicate that exocrine pancreatic function and the morphologic changes of the main pancreatic duct are significantly related. Dynamic ultrasonographic findings may reflect pancreatic function; consequently, this test may be a useful tool in the diagnosis of chronic pancreatitis.

Adult↗

PubMed2002

Molecular cloning and characterization of chymopasin, a novel serine protease from rat pancreas.

INTRODUCTION: Pancreas secretes many enzymes for food digestion into the pancreatic juice. We cloned a novel serine protease, chymopasin, from rat pancreas. AIMS: To know the localization of this enzyme in the pancreas and to analyze the enzymatic characteristics. METHODOLOGY: We cloned chymopasin cDNA using 3' and 5' RACEs. Northern blot and in situ hybridization were used to study the expression of this enzyme. Recombinant chymopasin protein produced by was analyzed by Western blot using specific antibody, and its enzymatic characteristics were examined using commercially available synthetic substrates, fibrin and gelatin. RESULTS: The open reading frame of rat chymopasin consisted of 792 bp encoding 264 amino acid residues. The deduced amino acid sequence contained the essential catalytic triad characteristic of the serine protease family. There was no putative N-glycosylation site. The amino acid sequence of rat chymopasin showed 54.5% identity to rat chymotrypsin B. Northern blot analysis showed that the transcript was strongly expressed in the pancreas. In situ hybridization with digoxigenin-labeled cRNA probe showed that the positive signals were observed in the acinar cells, but not in the islet or duct cells. Chymopasin protein was detected in the pancreas homogenate and bile-pancreatic juice. Further, cerulein stimulated the secretion of rat chymopasin into bile-pancreatic juice. CONCLUSION: These results suggested that rat chymopasin might be a digestive enzyme secreted from the acinar cells. From the enzyme assay using synthetic substrates, the purified recombinant chymopasin expressed in showed chymotrypsin-like activity. In addition, rat recombinant chymopasin showed fibrinolytic and gelatinolytic activities. These results suggested a role in the pathogenesis of pancreatic damage.

Amino Acid Sequence↗