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Biomedical subjects

H Fritz

Publications and source records attributed to H Fritz.

At least 217 records · Page 12Linked to original sources
PubMed1979

The isolation and properties of pig submandibular kallikrein.

The kallikrein from pig submandibular glands was highly purified, with an overall yield of 31%. Affinity chromatography on bovine basic pancreatic trypsin inhibitor linked to Sepharose 4B was an especially effective step in the purification procedure, giving a purification factor of 80. The enzyme is a single-chain molecule, occurring, as does pig urinary kallikrein, as a major B-form of apparent mol.wt. 39600 and minor amounts of an A-form of apparent mol.wt. 35900; the two forms can be separated by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. The amino acid composition of pig submandibular kallikrein is very similar to, but not quite identical with, that of the two-chain beta-kallikrein isolated from pig pancreatic autolysates. Submandibular kallikrein contains notably more glucosamine and hexoses than does pancreatic beta-kallikrein. Submandibular kallikrein, and also urinary kallikrein, exhibit an unusual biphasic hydrolysis of substrate esters that is not shared by pancreatic beta-kallikrein. For the submandibular enzyme, the K(m) for the initial reaction phase of the hydrolysis of alpha-N-benzoyl-l-arginine ethyl ester is 0.15+/-0.01mm (mean+/-s.e.m.), but rises to 0.69+/-0.04mm (mean+/-s.e.m.) in the stationary reaction phase; the V(max.) does not differ significantly between the two phases. The esterolytic activities of submandibular and urinary kallikreins on a number of esters of different amino acids resemble each other much more closely than those of pancreatic beta-kallikrein.

Amino Acids↗
PubMed1979

Proteinase inhibitors in severe inflammatory processes (septic shock and experimental endotoxaemia): biochemical, pathophysiological and therapeutic aspects.

Plasma levels of antithrombin III, alpha 2-macroglobulin and inter-alpha-trypsin inhibitor, as well as those of various clotting, complement and other plasma factors, were significantly decreased in 18 patients suffering from hyperdynamic septic shock. A similar statistically significant reduction of the concentrations of several plasma factors (prothrombin and antithrombin III, plasminogen and alpha 2-plasmin inhibitor, complement factor C3 and clotting factor XIII) was observed in experimental endotoxaemia. In this model the reduction in the plasma levels of these factors was considerably diminished by the intravenous injection of a granulocytic elastase--cathepsin G inhibitor of lower molecular weight from soybeans. The results of both studies indicate that consumption of plasma factors in the course of Gram-negative sepsis proceeds not only via the classical routes (by activation of the clotting, fibrinolytic and complement cascades by system-specific proteinases such as thrombokinase or the plasminogen activator) but also to an appreciable degree of unspecific degradation of plasma factors by neutral proteinases such as elastase and cathepsin G. The endotoxin-induced release of both sorts of proteinases, the system-specific ones and the unspecific lysosomal proteinases from leucocytes and other cells, is likely to be mainly responsible for the consumption of antithrombin III and alpha-2-macroglobulin via complex formation (followed by elimination of the complexes) and the increased turnover of the inter-alpha-trypsin inhibitor as observed in the clinical study. The therapeutic use of an exogenous elastase--cathepsin G inhibitor in the experimental model was stimulated by the observation that human mucous secretions contain and acid-stable inhibitor of the neutral granulocytic proteinases, called HUSI-I or antileucoproteinase. This inhibitor protects mucous membranes and soluble proteins against proteolytic attack by leucocytic proteinases released in the course of a local inflammatory response. Preliminary results indicate that HUSI-I, which is produced by the epithelial cells of mucous membranes, does not belong to any known structural type of acid-stable proteinase inhibitor. The search for other candidates suitable for medication in humans led to the discovery of a potent elastase--cathepsin G inhibitor, called eglin, in the leech Hirudo medicinalis. This acid-stable inhibitor with a molecular weight close to 8100 has an unusual structural property in that the structure of the molecule is not stabilized by any disulphide bridge.

Adolescent↗
PubMed1979

Studies of ciliated epithelia of the human genital tract. 3: Mucociliary wave activity in organ cultures of human Fallopian tubes challenged with Neisseria gonorrhoeae and gonococcal endotoxin.

Quantative determinations of the mucociliary activity of human Fallopian tube epithelium maintained as organ cultures were performed using a light beam reflex method. In non-infected organ cultures the mucociliary wave (MCW) frequency slowly decreased during the first 54 hours of culture maintenance. In organ cultures experimentally infected with fresh isolates of Neisseria gonorrhoeae producing T1/T2 colonies the MCW frequency either decreased to subnormal values or completely ceased whereas in organ cultured infected with a laboratory-adapted gonococcal strain the MCW frequencies remained within normal range. In organ cultures exposed to gonococcal endotoxin prepared from the laboratory-adapted strain, as well as in cultures in which cell-free filtrates of medium from organ cultures infected with N. gonorrhoeae (producing T1/T2 colonies) were added to the culture medium, the ciliary activity decreased and subsequently ceased. The same phenomenon occurred when organ cultures were challenged with Escherichia coli endotoxin. The ciliostatic effect appeared before any morphological changes in the surface epithelium, including the cilia, were demonstrable by scanning electron microscopy.

Adult↗
PubMed1979

Immunofluorescence studies indicate that the basic trypsin-kallikrein-inhibitor of bovine organs (Trasylol) originates from mast cells.

Using the indirect immunofluorescence technique, the basic kallikrein-trypsin inhibitor of bovine organs, Trasylol, could be localized in tissue mast cells of bovine lung, liver, pancreas and parotid gland. Identification of cells exhibiting specific fluorescence as tissue mast cells was achieved by combined light and electron microscopic diagnosis of bovine liver tissue sections. The presence of Trasylol in mast cells explains the widespread distribution of this inhibitor in functionally totally different organs or tissues of the bovine organism, as determined earlier by biochemical means. Identification of Trasylol as a mast cell constituent will facilitate the search for the biological function of this inhibitory protein in connection with a unique and highly specialized cell population.

Animals↗
PubMed1979

Inhibition of porcine glandular kallikreins by structurally homologous proteinase inhibitors of the Kunitz (Trasylol) type. Significance of the basic nature of amino acid residues in subside positions for kallikrein inhibition.

The newly synthesized chromogenic substrate D ValLeuArgNHNp was employed to study the inhibition strength of Trasylol-like inhibitors from bovine lung (TKI), sea anemone (SAI), snake venoms (NNV and HHV), snails (HPI) and cow colostrum (CTI) against porcine pancreatic, submandibular and urinary kallikreins. The dissociation constants of the corresponding kallikrein-inhibitor complexes were found close to Ki = 1.5 x 10(-9)M (TKI, SAI, NNV) or to Ki = 10--210 x 10(-9)M (HHV, HPI). CTI does not inhibit the three porcine glandular kallikreins. Comparison of the inhibitory active areas of the inhibitors with their affinities to the three kallikreins shows that kallikrein inhibition is observed only if basic amino acid residues are present in distinct positions of the inhibitory active sites.

Amino Acid Sequence↗
PubMed1979

Kallikrein inhibitors.

So far the Cl inactivator, alpha 2-macroglobulin, antithrombin III (in the presence of heparin), and alpha 1-antitrypsin have been identified as inhibitors of plasma kallikrein; alpha 1-antitrypsin reacts slowly also with tissue kallikreins. Of the various naturally occurring kallikrein inhibitors the basic trypsin-kallikrein inhibitor of bovine organs, aprotinin (the active substance of Trasylol), has attained by far the most interest. This inhibitor, which is produced by mast cells, has unusual properties due to its compact tertiary structure. Additional topics of aprotinin and structurally related inhibitors discussed are the mechanism of enzyme-inhibitor complex formation, the production of chemical mutants of aprotinin, the structural basis of kallikrein inhibition, and selected aspects regarding aprotinin medication.

Amino Acid Sequence↗
PubMed1979

[Hyperdynamic septic shock in man: concentration course of selected coagulation factors and plasma proteins].

Coagulation factors and plasma proteins are significantly decreased in patients with hyperdynamic septic shock. Besides the activation of the coagulation system, the endotoxin-induced release of granulocyte proteases is responsible for a septic disseminated intravascular coagulation. In this situation special emphasis should be placed on the levels of antithrombin III regarding application of heparin.

Antithrombin III↗
PubMed1978

Naturally occurring low molecular weight inhibitors of neutral proteinases from PMN-granulocytes and of kallikreins.

Human mucous secretions contain low molecular weight (Mr approximately 11,000) acid-stable inhibitors directed against elastase and cathepsin G from PMN-granulocytes. Important biochemical properties of these inhibitors are presented and their possible biological function is discussed. An inhibitor of glandular and plasma kallikreins preventing kinin-liberation from kininogen but not ester hydrolysis was obtained from rat kidney tubules. A molecular weight of about 4700 was estimated for this kallikrein-specific inhibitor (trypsin-induced kinin-liberation is not prevented).

Amino Acid Sequence↗
PubMed1978

Localization of kallikrein in porcine pancreas and submandibular gland as revealed by the indirect immunofluorescence technique.

The glandular kininogenase kallikrein is known to occur in many mammalian organs and glands but direct histochemical localization has been achieved in only a few cases. We have now been able to localize porcine kallikrein in the acinar cells of the pancreas and in the striated and collecting duct cells of the submandibular gland. Incubation of frozen and fixed sections with one of the crossreacting antibodies, anti-pancreatic, anti-submandibular or anti-urinary kallikrein IgG resulted in the same immunofluorescence pattern. There was evidence of a specific fluorescence neither in the acinar cells, nor in the interstitial tissue or blood cells of the submandibular gland nor in the islets of Langerhans, the interlobular ducts or blood vessels of the pancreas. From all data now available about glandular kallikreins, it seems that the kallikreins in these organs are very similar.

Animals↗
PubMed1978

Collection of control data from teratological experiments on mice, rats, and rabbits. A group study.

A joint study was undertaken in the laboratories of five pharmaceutical companies to evaluate accumulated data on the progeny of mice, rats and rabbits of various strains or breeds. The recorded morphological deviations from normal were classified according to the time of their occurrence during embryonic and foetal development, and three categories were differentiated. Comparison of the data from the various laboratories in general revealed similar results, and the variations observed are presumed to be due to differences in experimental conditions.

Animals↗
PubMed1977

Inhibition of three porcine glandular kallikreins by chloromethyl ketones.

In accordance with its lack of inhibitory activity against pig pancreatic kallikrein, Tos-LysCH2C1 has been shown also not to inhibit the porcine kallikreins from submandibular glands and from urine. Peptidyl-lysyl-chloromethanes, however, have been demonstrated to be irreversible inhibitors of all three enzymes. The rates of inhibition increase with increasing size of the amino acid residue in position P2 of the inhibitors. As expected from the known primary specificity of the pancreatic kallikrein, Gly-Val-ArgCH2C1 was found to be the most potent of the inhibitors studies. Kinetic constants for the inhibiton of the three porcine glandular kallikreins have been determined for two of the compounds. All data obtained suggest a close similarity of the three glandular kallikreins of the pig and even a possible identity of the enzymes from submandibular glands and from urine.

Animals↗
PubMed1977

Elastases from human and canine granulocytes, II. Interaction with protease inhibitors of animal, plant, and microbial origin.

Inhibitors of animal, plant, and microbial origin were tested against human and canine granulocytic elastases. The trypsin-chymotrypsin inhibitors from dog submandibular glands, from soybeans (Bowman-Birk) and from chickpeas show strong interaction with these proteases (Ki = 10(-8) - 10(-9)M). The trypsin-kallikrein inactivator of bovine organs (Trasylol) is not active against granulocytic elastases or against human granulocytic cathepsin G. Elastatinal, a specific inhibitor of elastases, isolated from actinomycetes (Streptomyces griseoruber), forms stable complexes with elastase from human (Ki = 6.2 X 10(-6)M) and canine granulocytes (Ki = 1.1 X 10(-6)M). A possible therapeutic application of these inhibitors for the inactivation of granulocytic proteases, which are able to degrade connective tissue in different pathological states, is discussed.

Animals↗