Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Trypsinogen”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 307 records · Page 17Linked to original sources
PubMed2000

High-affinity Ca(2+) binding inhibits autoactivation of rat trypsinogen.

The recent discovery that mutation Asn21 --> Ile in the human cationic trypsinogen (Tg) is associated with hereditary pancreatitis has brought into focus the functional role of amino acid 21 in mammalian Tgs. In the present paper, the effect of mutations Thr21 --> Asn and Thr21 --> Ile on the Ca(2+) dependence of zymogen activation was investigated, using the autolysis-resistant rat Tg mutant Arg117 --> His. In the absence of Ca(2+), rat Tg exhibited low but significant basal autoactivation, which was inhibited by micromolar concentrations of Ca(2+) (IC(50) 2.6 microM). Interestingly, basal autoactivation was diminished in both mutants, and no further inhibition by micromolar Ca(2+) was detectable. Millimolar Ca(2+) concentrations markedly and comparably stimulated autoactivation of wild-type and mutant zymogens (EC(50) 1.7-2.4 mM). The results indicate that rat Tg is subject to dual regulation by Ca(2+), allowing zymogen stabilization in a low-Ca(2+) environment and efficient activation in a high-Ca(2+) milieu.

Animals↗
PubMed1998

Affinity purification of recombinant trypsinogen using immobilized ecotin.

Affinity purification of inactive precursors (zymogens) of serine proteases on protease inhibitor columns is not feasible, due to the weak interaction between canonical protease inhibitors and protease zymogens. In this study we demonstrate that immobilized ecotin, a unique protease inhibitor from Escherichia coli, provides a superior affinity matrix for the purification of trypsinogen and possibly other serine protease zymogens as well.

Animals↗
PubMed1983

Purification and properties of genetic variants of mouse trypsinogen.

The presence of three trypsinogens (Try-III, Try-I, and Try-II) in the mouse is demonstrated by DEAE-cellulose column chromatography. Two genetic variants of Try-I are detected, because the activity of Try-I is different between the Mol-A strain and seven other strains. The Prt-3 locus controls the activity of Try-I. The Prt-3a gene exists in CFO, BS, KR, BALB/cJ, C57BL/6J, CBA/J, and 129/Sv-S1-CP strains, whereas the Prt-3b gene is present only in the Mol-A strain. Each Try-I from the CFO or Mol-A strain was purified. The fact that Try-I activity of the Mol-A strain is much higher than those of other strains is because of a difference in the specific activity; the ratio of the Kcat (sec-1) value with Tos-Arg-OMe to that with Bz-Arg-OEt is different between the variants from the CFO and those from the Mol-A strains, being much higher in the Mol-A strain. Also, chicken ovomucoid inhibited Try-I activity of the CFO strain at a molar ratio of one ovomucoid to two trypsins; Try-I activity of the Mol-A strain was only 50% inhibited even with an excess of ovomucoid. There was no difference between genetic variants of Try-I in molecular weight, Km values with Bz-Arg-OEt or Tos-Arg-OMe, pH optimum profile, or inhibition by soybean trypsin inhibitor.

Animals↗
PubMed1982

Diagnostic accuracy of serum cationic trypsinogen estimation for pancreatic diseases.

Serum immunoreactive trypsinogen (IT) levels were measured in 479 normal controls and in 604 patients (510 with nonpancreatic diseases and 94 with pancreatic diseases) in order to evaluate the distribution of IT values in the control population and the accuracy of the assay in the diagnosis of pancreatic diseases. It concentrations were normally distributed in the healthy population; children showed mean IT values significantly lower than adults. The sensitivity, specificity, and predictive value of a positive and negative result in diagnosing acute or chronic pancreatitis were evaluated vs normals and vs normals plus all patients. With an IT value higher than 80 ng/ml, the likelihood that a patient is not affected by acute pancreatitis is less than 5%. An IT value lower than 9 ng/ml detected 44% of chronic pancreatitis and was related to a 52% probability of such a condition. The 48% false positive results also include patients with pancreatic tumor (31% of cases), so that the chance of finding reduced IT levels in subjects without pancreatic damage drops to 17%. In view of the low prevalence of pancreatic diseases, IT assay should not be taken into consideration as a diagnostic screening test in the general population and its use should be limited to a hospitalized population.

Adolescent↗
PubMed1993

Non-specific elevation of immunoreactive trypsinogen in sick infants.

To determine the effect of neonatal illness on immunoreactive trypsinogen (IRT) levels, the IRT values obtained in sick infants transferred to a neonatal intensive care ward were compared with those found in matched controls. IRT levels from dried blood spots collected on day 4-5 of life from 372 sick infants had a mean value of 0.095 log transformed multiples of the median, whilst controls had a mean of -0.013: a highly significant difference. Classification of the sick infants into principal diagnostic categories failed to show any group contributing disproportionately to the observation. In particular, the level of elevation observed in 33 infants with gut abnormalities such as bowel obstruction, duodenal atresia, exomphalos and gastroschisis, in which some degree of pancreatic obstruction might be expected, was not greater than in other hospitalised infants. These data show that sick infants are at increased risk of being identified by an IRT screening programme aimed at detecting infants with cystic fibrosis.

Gastrointestinal Diseases↗
PubMed1995

Effect of microcirculatory perfusion on distribution of trypsinogen activation peptides in acute experimental pancreatitis.

Extraintestinal trypsinogen activation peptides (TAP) have been shown to correlate with severity of acute pancreatitis in humans as well as in various animal models. Ischemia superimposed on experimental pancreatitis, however, increases acinar cell injury without increasing TAP in plasma. We speculated that TAP generated in the pancreas might not reach the circulation in necrotizing pancreatitis due to decreased pancreatic perfusion. To test the hypothesis that generation of TAP in plasma is related to pancreatic perfusion and that plasma TAP may therefore underestimate acinar cell injury in necrotizing disease, we correlated TAP in pancreatic tissue and body fluids with capillary pancreatic blood flow in necrotizing and edematous pancreatitis. The ratio between necrosis and TAP in tissue was similar in both models; the ratio between TAP in plasma and tissue, however, was significantly lower in necrotizing pancreatitis, indicating that a certain amount of TAP generated in the pancreas did not reach the circulation. Decreased pancreatic perfusion found in necrotizing pancreatitis was consistent with this finding. Our data suggest that TAP in tissue is most reliable to indicate severity of acute pancreatitis, whereas plasma TAP may underestimate pancreatic injury in necrotizing disease due to decreased pancreatic perfusion.

Acute Disease↗
PubMed1998

Trypsinogen activation and glutathione content are linked to pancreatic injury in models of biliary acute pancreatitis.

CONCLUSION: In models of biliary acute pancreatitis, which might resemble the situation in humans, premature activation of trypsinogen inside the pancreas ("autodigestion") occurs and is correlated with the extent of ductal and parenchymal injury. It is accompanied by a critical spending of protease inhibitors and glutathione, compromising important acinar cell defense and maintenance mechanisms. BACKGROUND: Premature activation of pancreatic digestive enzymes and profound changes of levels of certain biochemical compounds have been implicated in the pathophysiology of acute pancreatitis. Hitherto, little information on their role in biliary acute pancreatitis has been available. METHODS: Three types of injury to the pancreaticobiliary duct system of various severity were induced in rats--ligation of the common bile-pancreatic duct, retrograde infusion of electrolyte, or retrograde infusion of taurocholate solution--and were compared to sham-operated animals. Trypsin, trypsin inhibitory capacity (TIC), reduced glutathione (GSH), and other compounds were measured in pancreatic tissue. Histopathology, as well as serum amylase, lipase, and gamma-glutamyl transferase (gamma GT) were assessed. RESULTS: Histopathology and elevated activity of gamma GT in the serum revealed increasing severity of pancreatic injury from sham operation through retrograde duct infusion with taurocholate. GSH was diminished even in macroscopically normal-appearing tissue, but significantly lower in altered (hemorrhagic)-looking sections. Conversely, tissue levels of trypsin were significantly increased. TIC was elevated only in the duct obstruction model, whereas it was reduced in the retrograde duct infusion models.

Acute Disease↗
PubMed1997

Urinary trypsinogen activation peptide (TAP) predicts severity in patients with acute pancreatitis.

CONCLUSIONS: Urinary TAP obtained within the first 48 h of the onset of symptoms can distinguish patients with severe acute pancreatitis. BACKGROUND: Urinary trypsinogen activation peptide (TAP) has recently been described as an early marker of severity in acute pancreatitis. METHODS: In a multicenter study, urine samples were collected for TAP concentration at 6-12, 24, and 48 h after admission from 139 patients with acute pancreatitis (99 with mild disease, 40 with severe disease) and from 50 control patients. Severity of acute pancreatitis was defined by the presence of organ failure and/ or pancreatic necrosis on dynamic contrast-enhanced computed tomography. RESULTS: Median urinary TAP in the 139 patients with acute pancreatitis compared to the 50 control patients was significantly higher at admission, 4.6 vs 0.8 ng/mL (p < 0.001), and 6-12 h, 1.9 vs 0.55 ng/mL (p = 0.04). Among patients who presented within 48 h of the onset of symptoms, the median urinary TAP for severe pancreatitis (9 patients) compared to mild pancreatitis (40 patients) was significantly higher at admission, 29.6 vs. 3.6 ng/mL (p = 0.001). Also, when obtained within 48 h of the onset of symptoms, all patients with severe pancreatitis had an admission urinary TAP level > 10 ng/mL. The sensitivity and specificity of an admission urinary TAP > or = 10 for severe pancreatitis was 100 and 85%, respectively. Given a cutoff of 10 ng/mL for an admission urinary TAP obtained within 48 h of the onset of symptoms, the negative predictive value was 100% for mild pancreatitis.

Acute Disease↗
PubMed1994

Trypsinogen expression by two human pancreatic cell lines CFPAC-1 and CAPAN-1. Modulation during spontaneous and induced cell growth.

We previously demonstrated that two human pancreatic adenocarcinoma cell lines, CFPAC-1 (established from a patient with cystic fibrosis) and CAPAN-1, were able to secrete trypsinogens 1 and 2 specifically. In order to analyze the relation of trypsin secretion to differentiation and cell growth, we undertook a comparative study of immunoreactive trypsin 1 (IRT) secretion by the two cell lines during cell growth in the presence and in the absence of various differentiating agents: sodium butyrate (NaBut), dimethylsulfoxide (DMSO), and dexamethasone (DX). In the presence of NaBut, IRT levels in the supernatants of both cell lines were slightly increased, whereas the cellular growth of both cell lines decreased significantly. In the presence of DX, IRT levels in cell culture conditioned media immediately and dramatically decreased, but the cell growth of neither cell line was affected by DX. An important increase in IRT levels was observed when CFPAC-1 cells and CAPAN-1 cells were grown in the presence of DMSO, but for both cell lines the cellular growth decreased in the presence of DMSO. Our data show that neither the IRT secretion level nor the differentiation state of these cell lines correlates with cellular growth, and suggests that the expression of pancreatic proteases by these two tumor cell lines could be either related to a common stem cell with this potential or to a possible acinar origin of pancreatic cancer, as recently proposed by others.

Adenocarcinoma↗
PubMed2001

Conformational study of proteins by SAXS and EDXD: the case of trypsin and trypsinogen.

The radius of gyration (Rg) of bovine trypsinogen and beta-trypsin was measured by an energy-dispersive X-ray technique (EDXD) and by small-angle X-ray scattering (SAXS), under different solvent conditions. Both techniques gave superimposable results. The experimental evidence demonstrated that: (1) no structural modifications and/or damage occurred during the data acquisition by EDXD; (2) at pH 4 the active enzyme has one class of chloride binding sites in common with the zymogen, whereas the latter protease shows an additional class able to reverse the effects on Rg induced by chloride at low concentration; and (3) the pH profile of the Rg of both proteases does not resemble at all the pH effect on beta-trypsin activity, a result in line with the finding that the electrical potentials induced by surface charge are small in absolute magnitude and produce no gradient across the active site.

Animals↗
PubMed2003

Characterisation of the progression of azaserine-induced rat pancreatic adenocarcinoma by proliferative cell nuclear antigen, basement membrane laminin and trypsinogen immunohistochemistry.

The progression of azaserine-induced rat pancreatic adenocarcinoma (AC) was characterised using quantitative and semiquantitative immunohistochemistry for proliferating cell nuclear antigen (PCNA), basement membrane laminin (BML) and trypsinogen (TG). Samples were taken 5-20 months after initiation. High PCNA-labelling indices (PCNA LIs) were measured 5 months after the induction of atypical acinar cell nodules (AACNs), which decreased later and stagnated until a further decline in the month 10 adenomas. Then a second premalignant proliferative wave was observed (month 13) within the adenoma stage. Later, in month 20 differentiated ACs PCNA LIs fell to the host tissue level but were found highest in the month 20 anaplastic ACs indicating a switch to malignant proliferation. Month 20 invasive ACs showed a number of separate proliferative foci. In early AACNs, BML decreased and remained low till the local maximum in the month 13 adenoma. Invasive ACs did not express BML. Month 5 AACN and differentiated AC were TG deficient but anaplastic AC regained its TG expression. However invasive AC was again TG negative. These results are discussed in combination with our previous data on progressional changes of autophagic capacity and microvessel densities.

Adenocarcinoma↗
PubMed1978

The two human trypsinogens: catalytic properties of the corresponding trypsins.

The catalytic properties of the two human trypsins obtained from purified trypsinogens have been studied. The catalytic rate constant kcat and the pK of the ionisable residue implicated in the active site have been determined with Bz-Arg-OEt. The hydrolysis of Tos-Arg-OMe by human trypsins does not follow the simple Michaelis-Menten scheme and indicates a difference in the conformational flexibility of the active site-regions of the two enzymes. Both enzyme are readily autolyzed and calcium ion plays a fundamental role in stabilizing trypsin activity. However trypsin 2 self-digests more rapidly than trypsin 1. These results are a prerequisite to the elucidation of the fate of pancreatic enzymes in human digestive tract.

Animals↗
PubMed1986

Increased pancreatic acinar content and secretion of cationic trypsinogen following 30-day continuous ethanol intoxication in rats.

The effects of sustained, high blood alcohol levels (216 +/- 120 mg/100 ml, S.D.) for 30 days on cholecystokinin (CCK)-mediated pancreatic exocrine function were studied in a rat model that achieves both maximally controlled, optimal nutrition and high alcohol intake (approximately 40.5% of total calories). In alcohol-fed rats, basal plasma levels of immunoreactive cationic trypsinogen (ICT) were reduced by 50% (P less than 0.05), but intravenous doses (0-30 IDU/kg/hr; 1 IDU = approximately 62.5 ng CCK-8) of cholecystokinin octapeptide (CCK-8) resulted in a 3-fold greater maximal concentration of ICT and an 80% steeper slope of the dose-response curve compared to those of pair-fed control animals. Basal plasma levels of amylase were not different in the two groups at basal conditions and did not change significantly following CCK-8 administration. In vitro studies with isolated pancreatic acini have shown that basal secretion of ICT into the media was similar in the two groups. However, ICT secretion in response to CCK-8 (30-3000 pM) was 2-fold greater in alcohol-fed rats than in pair-fed controls, resulting in a CCK-8 EC50 which was about half that of controls. On the contrary, the basal and maximal amylase secretion from acini isolated from alcohol-fed rats was reduced by 67 and 43%, respectively, causing a reduction in the magnitude of the response curve with almost identical EC50 and slopes. Despite the marked alterations in CCK-stimulated enzyme secretion, radioiodinated CCK-33 binding to receptors on acini isolated from both control and alcohol-fed rats was similar. Cellular concentrations of ICT and amylase, however, revealed similar patterns of alterations: 2 to 3-fold increase in ICT and 70% reduction in amylase in alcoholic acini compared to controls. These results indicate that the inverse changes in amylase and ICT secretions following continuous ethanol administration are probably due to differential effects on enzyme synthesis.

Alcoholism↗
PubMed1992

Determination of enterokinase activity by measuring the disappearance of trypsinogen.

An electrophoretic technique for the determination of enterokinase activity is described. The natural substrate trypsinogen is hydrolysed in the presence of soybean trypsin inhibitor. Under the conditions of assay, neither the trypsin inhibitor nor the trypsin-trypsin inhibitor complex are detected. Enterokinase activity can be determined in biological materials such as duodenal aspirates without any interference from trypsin activity. A significant correlation exists between the present technique and a spectrophotometric technique by which the liberation of trypsin activity is used to determine enterokinase activity.

Adolescent↗
PubMed1986

Oscillations of trypsinogen activation.

Trypsin activity oscillations are shown by the autocatalytic activation of trypsinogen at 0 degrees C in aqueous solution. The oscillations were observed for 3-4 days and show only slight decrease in enzyme activity. The zymogen has been kept at ice water temperature and pH 8.2 in the presence of Mn2+ ion. The mean periods of around 1.5 hr are about half of those found previously at -10 degrees C in frozen aqueous solution, while the amplitudes related to the mean activity are about one-fourth of that in the frozen experiments. The phenomenon of oscillation is interpreted in terms of coupling between the inhomogeneities of protein and ion concentrations of the unstirred solution and a Mn3+/Mn2+ system, causing synchronous, periodic reduction-oxidation of some cystine bridges in the protein chain. These nonequilibrium conditions, together with synchronous transitions among several conformational states, may produce the observed activity oscillations.

Enzyme Activation↗
PubMed1992

The isolation and partial characterization of trypsinogen, pancreatic secretory trypsin inhibitor and multiple forms of chymotrypsinogen and trypsin from the pancreas of the ostrich (Struthio camelus).

1. PSTI, two chymotrypsinogens and two trypsins were purified to homogeneity by acid extraction, salt fractionation, SP-Sephadex C-50 chromatography and RP-HPLC. 2. A third chymotrypsinogen, a trypsinogen and another trypsin were purified using an alkaline extraction procedure, followed by Trasylol- and Benzamidine-Sepharose affinity chromatography and hydroxylapatite chromatography. 3. The enzymes differed in amino acid composition as well as in specific activities towards synthetic amidase and esterase substrates. 4. N-terminal amino acid sequences were determined for one chymotrypsinogen and one trypsin.

Amino Acid Sequence↗