Acute pancreatitis. The correlation between clinical course, protease inhibitors, and complement and kinin activation.
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Acute Disease↗
Biomedical subjects
K Ohlsson
Publications and source records attributed to K Ohlsson.
Pancreatic secretory proteins in sera from rats before and after induction of experimental pancreatitis.
This study has traced the behavior of rat anionic trypsin-like immunoreactivity and pancreatic secretory trypsin inhibitor (PSTI) immunoreactivity in the serum of rats undergoing bile-pancreatic duct infusions of buffered solutions with and without the addition of the bile salt taurocholate. Enzymatic analysis of alpha-amylase was also done. A mild pancreatic inflammation followed infusion of buffer alone, as determined by gross inspection of the pancreas and the behavior of serum levels of the above proteins. Animals infused with buffer and 4% taurocholate had major inflammatory changes, including gross hemorrhage into the gland, and marked elevations in serum levels of the three proteins studied. Graphic analysis of the serum levels revealed distinct sharp rises in the serum levels of all three proteins in the taurocholate group. In the buffered saline group only an initial sharp rise was present, followed by a prolonged decrease back towards base-line values. The immunoreactive trypsin in the taurocholate group was present in three fractions with different molecular weights: trypsin in complex with protease inhibitors, trypsinogen, and trypsinogen, and degradation products. PSTI immunoreactivity showed the molecular size of free inhibitor and that of degradation products. The presence of trypsin in complex with protease inhibitors indicates the formation of active trypsin during acute pancreatitis, which is further supported by the presence of degradation products of trypsin and PSTI.
Animals↗
The effect of peritoneal lavage and aprotinin in the treatment of severe acute pancreatitis.
Fifty-five patients with severe acute pancreatitis were treated with peritoneal lavage at the Dept. of Surgery at Malmö General Hospital. In a randomized study 26 of the 55 patients received in addition 500,000 KIU aprotinin in the lavage fluid every 2 h. There were no significant differences between the aprotinin- and non-aprotinin-treated groups as to mortality and clinical results. The initial concentration of alpha 1-antitrypsin in plasma was mainly within normal range with increasing values during the treatment. No differences were seen between the two groups. The initial mean level of alpha 2-macroglobulin in plasma was slightly decreased, but 17 patients showed values below normal range. The alpha 2-macroglobulin level during the lavage showed a similar course in the two groups. alpha 1-Antitrypsin and alpha 2-macroglobulin in the lavage fluids showed signs of complexation but in plasma these inhibitors did not show any signs of complexation. On admission to the hospital the mean levels of C3 and kininogen in the plasma were slightly below normal. During the lavage treatment no differences were seen between the two groups. Degradation products of C3 and kininogen were seen in both serum and peritoneal fluids. The electrophoretic patterns of C3 and kininogen normalized in serum as well as in lavage fluids during the lavage treatment without any significant differences in the two groups. High levels of immunoreactive trypsin, pancreatic elastase, PSTI, and leukocyte elastase in serum were seen equally in both groups of patients.
Acute Disease↗
Determination of immunoreactive trypsin, pancreatic elastase and chymotrypsin in extracts of human feces and ileostomy drainage.
The total daily amount of extractable cationic trypsin, chymotrypsin, and pancreatic elastase 2 in feces and ileostomy fluids has been studied in normal individuals and healthy colectomized subjects. Quantitation was performed using immunological assays with polyethylene glycol as a fecal marker. The extractable amount of each of these enzymes in the feces of normal individuals was less than 1 mg/24 h. However, in fecal extracts from antibiotic-treated normal individuals a 100-fold increase in immunoreactive cationic trypsin was observed, while chymotrypsin and elastase 2 were only 2- to 3-fold higher. In extracts from ileostomy fluids cationic trypsin, elastase, and chymotrypsin all showed mean values in the order of 50-200 mg/24 h. The characterization of the immunoreactivity of pancreatic proteases showed no qualitative differences when measured in duodenal juice or fecal and ileostomy extracts.
Adult↗
Immuno-cross-reactivity between alpha-macroglobulins from pig, dog, rat and man including human pregnancy-associated alpha 2-glycoprotein.
The antigenic relationships between the alpha-macroglobulins in human blood plasma and in serum from pig, dog and rat were investigated using ordinary immunoelectrophoresis and line immunoelectrophoresis. The results imply that these alpha-macroglobulins are more or less antigenically related. This is true also for human pregnancy-associated alpha 2-glycoprotein which is the only alpha-macroglobulin without reported proteinase-inhibiting properties. Among the alpha-macroglobulins a reciprocal cross-reactivity was observed for eight pairs, indicating a close structural relationship.
Animals↗
Influence of plasma proteinase inhibitors and aprotinin on trypsin-induced bradykinin release in vitro in man.
The consumption of kininogen (measured as kinin-releasable material) was studied in an experimental model in vitro. Analyses were made following the addition of increasing amounts of human cationic trypsin to human serum and plasma. The consumption of kininogen was correlated with the degree of saturation of the plasma proteinase inhibitors alpha 2-macroglobulin (alpha 2-M) and alpha 1-proteinase inhibitor (alpha 1-PI) with trypsin in the presence and absence of aprotinin (Trasylol). The level of kininogen fell dramatically when alpha 2-M was saturated to 70% in spite of 90% free alpha 1-PI. Trypsin-alpha 2-M complexes had no effect on kininogen levels. 60 mumol/l of aprotinin, i.e. approximately 3 X 10(6) KIU/l, blocked only 60% of the trypsin-induced kininogen consumption in serum, while 15 mumol/l of aprotinin blocked 100% of this consumption in plasma. With increasing concentration of aprotinin in serum, a decreasing consumption of alpha 2-M and especially of alpha 1-PI was observed on the addition of trypsin. The high aprotinin concentration needed to block trypsin-induced kininogen cleavage in human serum or plasma may explain the poor clinical effect of aprotinin to date in human acute pancreatitis.
Animals↗
Quantification of granulocyte elastase inhibitors in human mixed saliva and in pure parotid secretion.
The predominant inhibitors of granulocyte elastase in plasma (alpha 1-proteinase inhibitor and alpha 2-macroglobulin) together with antileukoproteinase were quantified in parotid secretion and mixed saliva. Antileukoproteinase was the only inhibitor found in parotid saliva and was present in a concentration about 30 times the serum level, suggesting a local production. In mixed saliva, antileukoproteinase accounted for more than 70% of the molar concentration of the granulocyte elastase inhibitors studied. alpha 1-Proteinase inhibitor was measurable in about 1/3 of the specimens of mixed saliva. In parotid secretion, antileukoproteinase was present only as a free, active inhibitor. In mixed saliva about 15% of antileukoproteinase was in complex with granulocyte elastase, while the remaining amount of 85% was inhibitorily active. This suggests that antileukoproteinase has a biological function in a local defence mechanism directed towards the effects of granulocyte elastase in the oral cavity and salivary glands.
Blood Proteins↗
Studies on the interaction between leukocyte elastase, antileukoproteinase and the plasma proteinase inhibitors alpha 1-proteinase inhibitor and alpha 2-macroglobulin.
The dominating inhibitor of leukocyte elastase in human respiratory tract secretions is a low molecular mass inhibitor, designated antileukoproteinase. An equimolar antileukoproteinase-elastase complex was produced and subjected to gel filtration after differing time intervals and was found to be stable. On addition to human serum, however, elastase dissociated from antileukoproteinase and formed a complex with alpha 1-proteinase inhibitor. A small amount of elastase was also found bound to alpha 2-macroglobulin. Antileukoproteinase was capable of inhibiting elastase bound to alpha 2-macroglobulin. This inhibition was more complete and more rapid when the alpha 2-macroglobulin-elastase complex was in a molar ratio of 1:1 than in a ratio of 1:2.
Blood Proteins↗
A radioimmunoassay for rat pancreatic secretory trypsin inhibitor.
A radioimmunoassay for the detection of pancreatic secretory trypsin inhibitor (PSTI) in the rat is described. The sensitivity of the assay enables the specific measurement of this inhibitor in the serum of normal rats. The average base-line value for multiple animal serum specimens taken from fasting female Wistar rats being fed conventional diets was 11.6 +/- 6.2 micrograms/l. The inhibitor existed in its free form in serum, and PSTI immunoreactivity increased significantly within 2 h of the induction of experimental pancreatitis. The present assay will facilitate the study of PSTI in experimental diseases of the pancreas.
Animals↗
Elimination of pancreatic secretory trypsin inhibitor from the circulation. A study in man.
The elimination of human pancreatic secretory trypsin inhibitor (PSTI) from the circulation of man has been examined in two human volunteers. Serial samplings of blood and urine were made for 55 h, after a rapid intravenous infusion of 125I-labeled human PSTI. The findings demonstrated a rapid initial elimination from the circulation. Within 30 min only 30% of the infused label remained (T1/2, 6 min). This was accompanied by the rapid appearance in the urine of radiolabel. Our results indicate that PSTI would prove a poor diagnostic marker for acute pancreatitis late in the course of the disease. This is opposed to the findings of Ogawa et al., who reported prolonged elevated circulating levels of PSTI weeks into the disease. However, they also noted rises of PSTI during acute pancreatitis in excess of 10 times the levels we have noted. Further exploration of population differences and the behavior of PSTI during acute pancreatitis are necessary to help resolve these findings.
Acute Disease↗
The mucosal defence capacity against proteolytic leukocyte enzymes.
Antileukoprotease is an important inhibitor of leukocyte elastase and seems to be the primary defence factor against elastase in the respiratory tract. The circulating level of antileukoprotease increases in inflammatory diseases and seems to be related to the degree of inflammation of the lung parenchyma. Antileukoprotease cannot be included among the general acute phase reactants as it does not increase in connection with surgical trauma.
Cholecystectomy↗
An in vitro study of the influence of plasma protease inhibitors and aprotinin on trypsin-induced C3 cleavage in human serum.
Cleavage of native C3 in human serum following the addition of increasing amounts of human cationic trypsin was studied using an in vitro model. The cleavage was correlated with the degree of saturation of the plasma protease inhibitors alpha 2-macroglobulin and alpha 1-antitrypsin, and also with varying amounts of aprotinin (Trasylol). When alpha 2-macroglobulin reached 70% saturation, there was a prompt cleavage of most of the native C3 in spite of 90% free alpha 1-antitrypsin. The consumption of alpha 2-macroglobulin, and especially of alpha 1-antitrypsin, decreased with increasing concentrations of aprotinin. Aprotinin was needed in a concentration of 60 microM to block trypsin-induced C3 cleavage almost completely. This concentration is about 20 times higher than ever used clinically. One possible explanation of the poor clinical effect of aprotinin to date in human pancreatitis is the need for this high concentration.
Aprotinin↗
A zinc-dependent peptidase in prostatic organelles present in seminal plasma.
The electrophoretic seminal plasma protein pattern changes obviously within a few hours if the plasma is not frozen after the ejaculation. Mainly cathodal proteins disappear. Addition of serine protease inhibitors has no apparent affect, but o-phenanthroline markedly retards the conversions seen on electrophoresis. The subcellular organelles in seminal plasma are shown to contain a zinc ion dependent peptidase with optimal activity at pH 7.8. Estimations of enzyme activity may be performed using the elastase substrates n-tert butyloxycarbonyl-L-alanine-paranitrophenylester (Boc(Ala)) and succinyl(alanine)3-paranitroanilide (Suc(Ala)3pNA). The enzyme is inactivated by addition of o-phenanthroline and is completely reactivated by the addition of zinc ions.
Chemical Phenomena↗
Isolation and partial characterization of the pancreatic secretory trypsin inhibitor in the rat.
Isolation in a 55% yield of the low molecular weight pancreatic secretory trypsin inhibitor was achieved by gel filtration of an acid extract of whole inactive rat pancreas juice on Sephadex G-50 at pH 2.5 followed by desalting and ion-exchange chromatography on SP Sephadex C-50 at pH 4.5. Two distinct chromatographic fractions were obtained, labeled fraction 1 and 2. Fractions 1 and 2 showed three, respectively two, distinct closely migrating cationic bands on gel electrophoresis in barbital buffer, pH 8.6. Each fraction demonstrated one band on polyacrylamide disc electrophoresis at pH 4.6. The inhibitor is homogenous on gel filtration and on the basis of its stoichiometry with active site titrated rat anionic trypsin. Its molecular weight is approx. 6024. The amino acid composition is included. Rat pancreatic secretory trypsin inhibitor is trypsin-specific and interacts on a 1:1 molar basis with rat trypsin. It is a good inhibitor of bovine trypsin but a poor inhibitor of human cationic trypsin and its binding to trypsin is reversible by acidification. Like other inhibitors of this sort, it is present in about 0.1-0.2% of the total protein content of the juice, and normally exists in its free form. A simple procedure for the production of antiserum to the inhibitor which is a poor antigen is also described.
Amino Acids↗
Kinetics of the inhibition of leukocyte elastase by the bronchial inhibitor.
The rate constant for the association between human leukocyte elastase (EC 3.4.21.11) and human bronchial inhibitor has been determined by competition experiments with alpha 1-proteinase inhibitor. This constant (1.1.10(7) M(-1) . s(-1)) is 6-times lower than that for the association of leukocyte elastase and alpha 1-proteinase inhibitor. The latter inhibitor is able to dissociate the leukocyte elastase-bronchial inhibitor complex with a rate constant 1.3.10(-4) s-1. The equilibrium dissociation constant Ki of the complex is 1.2.10(-11) M. The physiopathological significance of these constants is discussed.
Bronchi↗
Protease inhibitors in rheumatoid synovial fluid. Analyses of electrophoretic homogeneity and protease inhibitory capacity.
Paired plasma and synovial fluids from 17 patients with seropositive rheumatoid arthritis were examined for electrophoretic homogeneity/heterogeneity and enzymic inhibitory capacity of the protease inhibitors. The high degree of saturation (approximately 90%) of the polyvalent protease inhibitor alpha 2-macroglobulin in the rheumatoid synovial fluid contrasts sharply with the low saturation of alpha 1-anti-trypsin. The inhibitory reactivity of the non-complexed fraction of both of these dominating antiproteases was retained (approximately 85-90%). Thus, a selective inactivation of synovial alpha 1-antitrypsin could not be demonstrated. alpha 1-Anti-chymotrypsin revealed electrophoretic homogeneity in all synovial fluids. Electrophoretic heterogeneity of the plasmin inhibitor antiplasmin was detected in the majority of synovial fluids indicating plasmin activation. The existence of a protease-antiprotease imbalance in the rheumatoid joint was indicated by the high degree of saturation of alpha 2-macroglobulin and a cleavage of C3 in rheumatoid synovial fluids.
Arthritis, Rheumatoid↗
Release of proteolytic enzymes from leucocytes attached to IUDs.
The leucocytes adhering to intrauterine devices (IUDs) were predominantly mononuclear phagocytic cells (MPCs) and granulocytes. These cells released elastase and a plasminogen activator in the culture medium. The plasminogen activator was found to be immunologically identical to tissue activator, and the release pattern indicated that the activator as well as elastase were released from both MPCs and granulocytes. Thus, the results suggest the generalized conclusion that both MPCs and granulocytes release the tissue activator-type of plasminogen activator. The urokinase-type of plasminogen activator, which was detected initially in some cultures, may originate from endometrial tissue fragments adhering to the IUD. IUDs removed in the end of the menstrual phase and in the midcycle phase released more plasminogen activator than did devices removed at the proliferative and luteal phases. No such cyclic variation was found for the release of elastase.
Female↗
Serum studies of leucocyte elastase in acute and chronic lung diseases.
Immunoreactive leucocyte elastase was measured in the serum of patients with chronic obstructive bronchitis. No evidence was found to demonstrate the release of this enzyme in the pulmonary circulation. However the average serum concentrations (573 . 0 micrograms/l; SD +/- 261 . 0) were higher (2p less than 0 . 001) in this group of patients than in age matched control subjects (355 . 2 micrograms/l; SD +/- 274 . 8). Further studies confirmed this finding but patients with other active lung diseases had similarly increased leucocyte elastase concentration in the serum. This suggests that a raised serum leucocyte elastase concentration is a feature of active lung diseases and not a feature of obstructive bronchitis alone.
Acute Disease↗