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PubMed2002

Elevated levels of trypsinogen-2 and trypsin-2-alpha1-antitrypsin in sera of infants and children after cardiac surgery.

Acute pancreatitis is a known complication of cardiac surgery with cardiopulmonary bypass but amylase is not a reliable marker in infants. We evaluated whether the serum concentrations of trypsinogen-2 and trypsin-2-alpha1-antitrypsin (AAT) can be used to study disturbances in pancreatic function in children and infants undergoing cardiac surgery. The study comprised 21 infants < 1 year and 25 children aged 1-16 years undergoing cardiopulmonary bypass at the Children's Hospital, Helsinki University Central Hospital. Consecutive serum samples were taken before surgery, at 12 h, 1, 2 and 3 days after surgery, and before discharge from the hospital. A moderate increase in trypsinogen-2 and trypsin-2-AAT in serum was found in more than two-thirds of the patients. On day 3, there was a 4.3-fold mean increase (CI 95% 2.8-6.5) in trypsinogen-2 and a 2.4-fold mean increase (CI 95% 1.8-3.1) in trypsin-2-AAT. In 4 patients trypsinogen-2 was elevated by more than 20-fold. One patient had clinical pancreatitis, but there were no clinical signs of pancreatitis in the other three patients. The changes in trypsinogen-2 and trypsin-2-AAT were similar in infants and children. The moderate increase in the serum concentrations of trypsinogen-2 and trypsin-2-AAT after cardiac surgery in the absence of signs of pancreatitis may be due to a subclinical pancreatic disturbance, but it could also be caused by an inflammatory response and expression of extrapancreatic trypsin. Contrary to amylase, trypsinogen-2 is expressed in the pancreas of infants.

Acute Disease↗
PubMed1987

In vitro mutagenesis of trypsinogen: role of the amino terminus in intracellular protein targeting to secretory granules.

The mouse anterior pituitary tumor cell line, AtT-20, targets secretory proteins into two distinct intracellular pathways. When the DNA that encodes trypsinogen is introduced into AtT-20 cells, the protein is sorted into the regulated secretory pathway as efficiently as the endogenous peptide hormone ACTH. In this study we have used double-label immunoelectron microscopy to demonstrate that trypsinogen colocalizes in the same secretory granules as ACTH. In vitro mutagenesis was used to test whether the information for targeting trypsinogen to the secretory granules resides at the amino (NH2) terminus of the protein. Mutations were made in the DNA that encodes trypsinogen, and the mutant proteins were expressed in AtT-20 cells to determine whether intracellular targeting could be altered. Replacing the trypsinogen signal peptide with that of the kappa-immunoglobulin light chain, a constitutively secreted protein, does not alter targeting to the regulated secretory pathway. In addition, deletion of the NH2-terminal "pro" sequence of trypsinogen has virtually no effect on protein targeting. However, this deletion does affect the signal peptidase cleavage site, and as a result the enzymatic activity of the truncated trypsin protein is abolished. We conclude that neither the signal peptide nor the 12 NH2-terminal amino acids of trypsinogen are essential for sorting to the regulated secretory pathway of AtT-20 cells.

Adrenocorticotropic Hormone↗
PubMed2001

Time-course and clinical value of the urine trypsinogen-2 dipstick test in acute pancreatitis.

OBJECTIVE: Urine trypsinogen-2 has been suggested as a marker of damage due to acute pancreatitis. Our aim was to assess the time-course and the clinical value of this test in acute pancreatitis. METHODS: A urine trypsinogen-2 dipstick test was performed on 30 patients with acute pancreatitis upon admission to the emergency room, as well as on 30 patients with non-pancreatic acute abdominal pain, and in 30 healthy subjects. RESULTS: In 53.3% of the patients with acute pancreatitis the dipstick test showed abnormal urine trypsinogen-2 whereas this test gave negative results in all patients with non-pancreatic acute abdomen and in all healthy subjects. Patients with severe acute pancreatitis had a frequency of abnormal results of urine trypsinogen-2 (8/9, 88.9%; 95% CI, 51.8-99.7%) significantly higher (P = 0.031) than those with the mild disease (8/21, 38.1%; 95% CI, 18.1 -61.6%), while no significant differences were found in the urine trypsinogen-2 results between patients with biliary acute pancreatitis and those with non-biliary acute pancreatitis. Regarding the time-course of urine trypsinogen-2, there were no significant differences during the three days of the study. CONCLUSIONS: The specificity of urine trypsinogen-2 in the diagnosis of acute pancreatitis is good however its sensitivity is low.

Acute Disease↗
PubMed1992

Monoclonal antibodies to human pancreatic trypsin 1 inhibit the activation of human trypsinogens 1 and 2.

Two monoclonal antibodies (Mab) raised against human pancreatic trypsin 1, Mab G6 and A8, were previously isolated and characterized. The two Mab which recognize trypsinogen 1 are found to inhibit the activation of trypsinogen 1 by enterokinase. The inhibition of activation by the two Mab is concentration-dependent, rapid and virtually complete with Mab G6. Activation of trypsinogen 2 is totally inhibited by Mab G6, while Mab A8 has no effect on the activation of trypsinogen 2. The two monoclonal antibodies have opposite effects on the proteolytic activity of trypsin 1; Mab G6 increases proteolytic activity while Mab A8 inhibits trypsin activity by as much as 40%. This inhibition is concentration dependent but cannot account for the complete inhibition of activation of trypsinogen 1. Neither monoclonal antibody significantly inhibits the esterolytic activity of either form of human trypsin. Western-blot analysis of the reactivity of the two monoclonal antibodies with trypsinogens of various species shows that only Mab G6 cross-reacts with dog trypsinogen.

Animals↗
PubMed2003

A single mutation in the activation site of bovine trypsinogen enhances its accumulation in the fermentation broth of the yeast Pichia pastoris.

We produced bovine trypsinogen in the yeast Pichia pastoris. Little or no trypsinogen was detected when the gene with its native leader sequence was expressed under the control of the strong aox1 promoter, suggesting that expression of the wild-type bovine trypsinogen was toxic to the cells. We altered the trypsinogen native propeptide sequence by replacing the lysine at position 6 with an aspartic acid, thus destroying the site in the propeptide cleaved by enterokinase and by trypsin. This mutant accumulated up to 10 mg of trypsinogen per liter in shake flask cultures and about 40 mg/liter in 6-liter fermentors. Trypsinogen could be activated in vitro with a dipeptidyl-aminopeptidase, which selectively removed the modified trypsinogen propeptide; the resulting trypsin was fully active and showed evidence of glycosylation. Thus, we have developed a novel protein production scheme that can be used for the expression of proteins, such as proteases, that are deleterious to the producing organism. This system relies on the expression of a zymogen that cannot be activated in vivo coupled with its in vitro purification and activation.

Animals↗
PubMed1991

Neonatal screening strategy for cystic fibrosis using immunoreactive trypsinogen and direct gene analysis.

OBJECTIVE: To assess the effectiveness of a two tier neonatal screening strategy for cystic fibrosis, which combines estimation of immunoreactive trypsinogen followed by direct gene analysis in dried blood spot samples collected at age 5 days. DESIGN: Prospective study of two tier screening strategy. The first tier of testing immunoreactive trypsinogen concentration was measured in dried blood spot samples from neonates aged 4-5 days. In the second tier direct gene analysis to detect cystic fibrosis mutations deltaF508 and deltaI506 was performed in those blood spot samples which produced the highest 1% of immunoreactive trypsinogen values. Direct gene analysis was also performed on blood spot samples from infants with suspected or confirmed meconium ileus, regardless of the immunoreactive trypsinogen value. SETTING: The South Australian Neonatal Screening Programme, operating from the department of chemical pathology at Adelaide Children's Hospital. Subjects--All 12,056 neonates born in South Australia between December 1989 and June 1990. No selection criteria were applied. INTERVENTIONS: All infants found to have two recognised cystic fibrosis mutations on direct gene analysis were referred directly for clinical management, and those with one recognised cystic fibrosis mutation were recalled for a sweat test; their families were given genetic counselling. MAIN OUTCOME MEASURES: Direct or exclusion of cystic fibrosis by sweat testing of neonates identified as being at high risk of cystic fibrosis on screening and of those at minimum risk but whose subsequent clinical history raised suspicion about the disease. RESULTS: Of the 12,056 infants screened, 11,907 (98.8%) were reported as "cystic fibrosis not indicated" on the basis of low immunoreactive trypsinogen values. Of the 148 (1.23%) infants with raised immunoreactive trypsinogen values and one (0.008%) with meconium ileus, 132 (1.09%) were reported as cystic fibrosis not indicated, four (0.033%) were identified as having cystic fibrosis, and 13 (0.108%) were recalled for sweat testing after direct gene analysis for the presence of the deltaF508 and deltaI506 cystic fibrosis mutations. No cases of affected infants are known to have been missed to date. CONCLUSION: The strategy of measurement of immunoreactive trypsinogen followed by direct gene analysis is a highly specific neonatal screen for cystic fibrosis, requiring only 2.8 families to be contacted for every case of cystic fibrosis diagnosed.

Cystic Fibrosis↗
PubMed1982

Plasma pancreatic trypsinogens in chronic renal failure and after nephrectomy.

The kidney has previously been shown to be a major site for the plasma clearance of pancreatic trypsinogens in the rat. This study investigated plasma concentrations of anionic and cationic trypsinogen in chronic renal failure and anephric patients. Plasma concentrations were significantly elevated in both groups of patients. Hemodialysis did not change their plasma levels. The plasma levels of anionic and cationic trypsinogens were highly correlated in patients and normal subjects; however, the relative concentrations of anionic trypsinogen were significantly higher in renal failure patients. This suggests that in patients with renal failure the secondary clearance mechanisms for these plasma proteins more efficiently clear cationic molecules. In normal dogs, intravenous infusion of synthetic octapeptide of cholecystokinin (CCK-8) resulted in small transitory increases in plasma trypsinogen levels. After nephrectomy, basal levels of anionic and cationic trypsinogen were elevated, and intravenous infusion of CCK-8 resulted in prolonged, high levels of plasma trypsinogens.

Animals↗
PubMed1998

Intra-acinar cell activation of trypsinogen during caerulein-induced pancreatitis in rats.

Supramaximal stimulation of the pancreas with the CCK analog caerulein causes acute edematous pancreatitis. In this model, active trypsin can be detected in the pancreas shortly after the start of supramaximal stimulation. Incubation of pancreatic acini in vitro with a supramaximally stimulating caerulein concentration also results in rapid activation of trypsinogen. In the current study, we have used the techniques of subcellular fractionation and both light and electron microscopy immunolocalization to identify the site of trypsinogen activation and the subsequent fate of trypsin during caerulein-induced pancreatitis. We report that trypsin activity and trypsinogen-activation peptide (TAP), which is released on activation of trypsinogen, are first detectable in a heavy subcellular fraction. This fraction is enriched in digestive enzyme zymogens and lysosomal hydrolases. Subsequent to trypsinogen activation, both trypsin activity and TAP move to a soluble compartment. Immunolocalization studies indicate that trypsinogen activation occurs in cytoplasmic vacuoles that contain the lysosomal hydrolase cathepsin B. These observations suggest that, during the early stages of pancreatitis, trypsinogen is activated in subcellular organelles containing colocalized digestive enzyme zymogens and lysosomal hydrolases and that, subsequent to its activation, trypsin is released into the cytosol.

Acute Disease↗
PubMed1999

Trypsin and activation of circulating trypsinogen contribute to pancreatitis-associated lung injury.

Pancreatic proteases are secreted in acute pancreatitis, but their contribution to associated lung injury is unclear. Applying models of mild edematous (intravenous caerulein) and severe necrotizing (intraductal glycodeoxycholic acid) pancreatitis in rats, we showed that both trypsinogen and trypsin concentrations in peripheral blood, as well as lung injury, correlate with the severity of the disease. To isolate the potential contribution of proteases to lung injury, trypsin or trypsinogen was injected into healthy rats or trypsinogen secreted in caerulein pancreatitis was activated by intravenous enterokinase. Pulmonary injury induced by protease infusions was dose dependent and was ameliorated by neutrophil depletion. Trypsinogen activation worsened lung injury in mild pancreatitis. In vitro incubation of leukocytes with trypsinogen showed that stimulated leukocytes can convert trypsinogen to trypsin. In conclusion, this study demonstrates that the occurrence and severity of pancreatitis-associated lung injury (PALI) corresponds to the levels of circulating trypsinogen and its activation to trypsin. Neutrophils are involved in both protease activation and development of pulmonary injury.

Acute Disease↗
PubMed1998

Cationic trypsinogen produced by human pancreatic ductal cancer has the characteristics of spontaneous activation and gelatinolytic activity in the presence of proton.

We examined whether human pancreatic ductal cancer cells express and secrete pancreatic cationic trypsinogen in vitro which can be spontaneously converted into active trypsin at acidic pH (pH 4.5-5. 5), in contrast to anionic trypsinogen. Cationic trypsinogen expression at the mRNA level was observed in differentiated Capan-1 and BxPC-3 cell lines. However, expression was not detected in either poorly-differentiated Panc-1 or undifferentiated MIAPaCa-2 cell line. The gelatinolytic activity of the activated form of trypsinogen in each conditioned medium in the presence of enterokinase (1.0 microg/ml) (a band with a molecular weight of approximately 23 kDa) corresponded well to the level of cationic trypsinogen mRNA. The spontaneous activation of trypsinogen also was observed by gelatin zymography of the acid-loaded conditioned medium (pH 5.5). These findings suggest that trypsinogen produced by human pancreatic ductal cancer has the characteristics of spontaneous activation and gelatinolytic activity in the presence of proton.

Culture Media, Conditioned↗
PubMed1995

Trypsinogen expression in human ovarian carcinomas.

Increased secretion of matrix metalloproteinases and serine proteinases is well known to be associated with cancer invasion and metastasis. We aimed to elucidate the implication of trypsin, a serine proteinase and a representative digestive enzyme in invasion and metastasis of human carcinomas. Northern blot, RT-PCR and Western blot analyses and immunohistochemical studies were performed to detect and analyze trypsinogen expression in 5 ovarian carcinoma cell lines and 10 human ovarian carcinoma tissues using a DNA probe for trypsinogen I, and monoclonal and polyclonal antibodies to human trypsin I. Among the 5 ovarian carcinoma cell lines, only the MCAS (mucinous cystadenocarcinoma) cell line showed a high level of trypsinogen production and mRNA expression by Western and Northern blot analyses, respectively. However, Southern blot analysis of RT-PCR products could detect considerable levels of trypsinogen mRNA in all ovarian cancer cell lines. In Northern analysis of ovarian cancer tissues, all advanced cancer samples showed trypsinogen gene expression. Serous cystadenocarcinomas exhibited particularly high levels of gene expression. Immunohistochemical staining also detected trypsin in ovarian carcinoma tissues. In contrast, normal ovaries and tumors with low malignant potential did not show trypsinogen expression. Our results demonstrate the extra-pancreatic production and distribution of trypsinogen in human ovarian carcinomas.

Adenocarcinoma↗
PubMed2002

Cathepsin B cleavage of the trypsinogen activation peptide.

BACKGROUND: Cathepsin B is thought to play a central role in intrapancreatic trypsinogen activation and the onset of pancreatitis. A recent investigation of the cathepsin B mediated activability of wildtype trypsinogen and their mutations N29I, N29T and R122H, which are associated to hereditary pancreatitis, revealed no differences. This action seems to be restricted to the K23-I24 peptide bond, which is the trypsinogen activation bond. Here we investigated the influence of the mutations D22G and K23R of the trypsinogen activation peptide on the cleavability by cathepsin B. METHODS: To investigate the functional impact of the TAP mutations on cathepsin B mediated cleavage of the trypsinogen activating K23-I24 bond, the corresponding peptides pWT, APFDDDDKIVGG; pD22G, APFDDDGKIVGG; and pK23R, APFDDDDRIVGG were digested with cathepsin B for 30 min at pH 3.8 and 5.0, and the fragments were analysed by high-performance liquid chromatography. RESULTS: Without cathepsin B, less than 1 % of the peptides were hydrolysed. After a 30-minute digestion with cathepsin B at pH 5, 96% of pWT, 48% of pK23R, but only 2.4% of pD22G were hydrolysed. At pH 3.8, the cathepsin B cleavage of pWT and pK23R was less than at pH 5, whereas the cleavage of pD22G was completely inhibited. CONCLUSIONS: Cathepsin B mediated trypsinogen activation seems not to be a crucial pathogenic step in hereditary pancreatitis patients with the trypsinogen mutations D22G and K23R.

Cathepsin B↗
PubMed1998

Isolation of cDNAs for trypsinogen from the winter flounder, Pleuronectes americanus.

Knowledge of the timing of digestive enzyme expression in developing larvae is essential for evaluating the appropriateness of formulated larval diets. Since little is known at the molecular biological level about the ontogeny of digestive enzyme function in flatfish, we have isolated cDNA clones for key digestive enzymes such as trypsinogen. Portions of trypsinogen genes have been amplified from winter flounder cDNA libraries by PCR using primers based on sequence motifs conserved among trypsinogen genes from other organisms. The PCR products were sequenced, cloned, and used as radioactively labeled probes to screen the libraries. Three distinct trypsinogen cDNAs have been isolated, representing the first cDNAs for winter flounder digestive enzymes. The first type (Flounder 1) is very similar to a trypsinogen sequence reported from a related flounder, Pleuronectes platessa. The second type (Flounder 2) is related to sequences reported from Atlantic salmon, cod, and the Antarctic fish, Paranotothenia magellanica. The third type (Flounder 3) shows limited similarity to the Antarctic fish trypsinogen sequence. All three cDNAs encode a cleavable signal sequence at the amino-terminal end, and Flounder 1 and 2 contain the characteristic acidic sequence for activation of the trypsinogen proenzyme to trypsin. Southern hybridization experiments indicate that Flounder 1 and 3 are single-copy genes, whereas Flounder 2 may be present in more than one copy. In addition, Flounder 2 detects homologs in a wide variety of other fish species. The sequence information will be used to establish RT-PCR assays for larval winter flounder (Pleuronectes americanus) digestive enzyme expression.

Journal Article↗
PubMed2001

Molecular pathology and evolutionary and physiological implications of pancreatitis-associated cationic trypsinogen mutations.

Since the identification in 1996 of a "gain of function" missense mutation, R122H, in the cationic trypsinogen gene (PRSS1) as a cause of hereditary pancreatitis, continued screening of this gene in both hereditary and sporadic pancreatitis has found more disease-associated missense mutations than expected. In addition, functional analysis has yielded interesting findings regarding their underlying mechanisms resulting in a gain of trypsin. A critical review of these data, in the context of the complicated biogenesis and complex autoactivation and autolysis of trypsin(ogen), highlights that PRSS1 mutations cause the disease by various mechanisms depending on which biochemical process they affect. The discovery of these mutations also modifies the classical perception of the disease and, more importantly, reveals fascinating new aspects of the molecular evolution and normal physiology of trypsinogen. First, activation peptide of trypsinogen is under strong selection pressure to minimize autoactivation in higher vertebrates. Second, the R122 primary autolysis site has further evolved in mammalian trypsinogens. Third, evolutionary divergence from threonine to asparagine at residue 29 in human cationic trypsinogen provides additional advantage. Accordingly, we tentatively assign, in human cationic trypsinogen, the strongly selected activation peptide as the first-line and the R122 autolysis site as the second-line of the built-in defensive mechanisms against premature trypsin activation within the pancreas, respectively, and the positively selected asparagine at residue 29 as an "amplifier" to the R122 "fail-safe" mechanism.

Amino Acid Sequence↗
PubMed1987

Binding of the Ile-Val and Val-Val effector dipeptides to the binary adducts of bovine trypsinogen with Kunitz and Kazal inhibitors as well as the acylating agent p-nitrophenyl p-guanidinobenzoate. A thermodynamic and kinetic study.

Thermodynamics and kinetics of binding of the Ile-Val and Val-Val effector dipeptides to the binary adducts of bovine trypsinogen with the bovine basic pancreatic trypsin inhibitor (BPTI, Kunitz inhibitor), the porcine pancreatic secretory inhibitor (PSTI, Kazal inhibitor) and the acylating agent p-nitrophenyl p-guanidinobenzoate have been investigated at pH 7.4 and 21(+/- 0.5) degrees C. The affinity of both effector dipeptides for bovine trypsinogen: BPTI and bovine trypsinogen: PSTI binary adducts is higher than that observed for the formation of the dipeptide: bovine trypsinogen: p-guanidinobenzoate ternary complexes; moreover, the affinity of Ile-Val for the zymogen binary adducts is higher than that observed for Val-Val association. Binding of Ile-Val and Val-Val to the bovine trypsinogen binary complexes conforms to the induced-fit model, which consists of a fast pre-equilibrium followed by intramolecular isomerization change(s), the latter fast pre-equilibrium followed by intramolecular isomerization change(s), the latter representing the rate-limiting first-order process. For the three bovine trypsinogen systems considered, the rate of the intramolecular isomerization change(s) is essentially independent of the nature of the dipeptide and of the proenzyme binary complex.

Animals↗
PubMed1997

Cerulein-induced in vitro activation of trypsinogen in rat pancreatic acini is mediated by cathepsin B.

BACKGROUND & AIMS: One of the central, unresolved issues in the pathogenesis of acute pancreatitis is the uncertainty regarding the mechanisms responsible for the premature intrapancreatic activation of digestive enzyme zymogens. The aim of the current study was to develop and characterize an in vitro system that might mimic the events leading to trypsinogen activation within the pancreas during pancreatitis. METHODS: Activation of trypsinogen in response to stimulation with cerulein was quantitated in isolated rat pancreatic acini. RESULTS: Activation of trypsinogen was detected within 10 minutes of exposing isolated rat pancreatic acini, in Ca2+-containing buffer, to a supramaximally stimulating concentration of cerulein in vitro. Complete inhibition of pancreatic cathepsin B activity with E-64d, a specific, potent and irreversible cathepsin B inhibitor, prevents cerulein-induced in vitro trypsinogen activation. CONCLUSIONS: In vitro activation of trypsinogen can be detected when pancreatic acini are exposed to a supramaximally stimulating dose of cerulein. The results using this in vitro system support the hypothesis that the appearance of active trypsin within the pancreas during the early stages of cerulein-induced pancreatitis reflects activation of trypsinogen by the lysosomal hydrolase cathepsin B.

Amylases↗
PubMed1999

Interstitial trypsinogen release and its relevance to the transformation of mild into necrotizing pancreatitis in rats.

BACKGROUND & AIMS: Intracellular activation of trypsinogen is currently believed to initiate pancreatitis. Factors responsible for the progression of mild to necrotizing pancreatitis are poorly understood. This study evaluated the significance of interstitial protease release and activation in this process. METHODS: In rats with cerulein-induced pancreatitis, concentrations of trypsinogen and its activation peptide TAP were measured in lymph and blood, and pancreatic injury was determined. Activation of extracellular trypsinogen was induced by intravenous infusion of enterokinase, which does not enter the acinar cell. Gabexate mesilate (acinar cell permeable) or soybean trypsin inhibitor (acinar cell nonpermeable) was administered to distinguish the effects of intracellular or extracellular protease activation. RESULTS: In cerulein pancreatitis, trypsinogen levels increased prominently and were highest in lymph and portal vein blood, whereas TAP increments were modest. Combined cerulein/enterokinase infusions resulted in marked TAP increases in lymph and blood and in severe necrohemorrhagic pancreatitis. Gabexate mesilate as well as soybean trypsin inhibitor significantly decreased TAP levels in both lymph and blood and reduced pancreatic injury, with no significant differences between groups. CONCLUSIONS: In secretagogue-induced pancreatitis, large amounts of trypsinogen are present in the interstitium and drain via the portal and lymphatic circulation. Activation of this extracellular trypsinogen induces hemorrhagic necrosis in a setting of mild edematous pancreatitis. This phenomenon may be the central event in the progression to fulminant necrotizing pancreatitis.

Animals↗
PubMed1997

Trypsinogen activation in rat pancreatic acinar cells hyperstimulated by caerulein.

Inappropriate trypsinogen activation is discussed as an early intracellular event in the secretagogue-induced model of acute pancreatitis. However, the mechanisms by which trypsinogen is activated are not well characterized. In the present work, trypsinogen activation was studied in intact acinar cells using bis-(CBZ-arginyl)-Rhodamine 110 [(CBZ-Arg)2-Rho 110] as a cell-permeant substrate for trypsin and also independently via the formation of trypsinogen activation peptide (TAP). Preincubation with 10 nM caerulein increased the Rho 110-substrate cleavage more than threefold. This proteolytic activity was fully sensitive to a benzamidine (BA)-type serine protease inhibitor. The appearance of enzymatic activity was paralleled by the formation of TAP. The lack of effect of the high-molecular soybean trypsin inhibitor indicates an intracellular substrate cleavage. The cathepsin B inhibitor CA-074 prevented neither the caerulein-induced formation of TAP nor the (CBZ-Arg)2-Rho 110-cleaving activity. BA inhibited the Rho 110-substrate cleavage and significantly reduced the TAP formation. These results show that trypsinogen activation in caerulein-hyperstimulated acinar cells may occur independently of the activity of cathepsin B. On the contrary, the effect of BA suggests the role of a serine protease in trypsinogen activation.

Animals↗