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Biomedical subjects

H Fritz

Publications and source records attributed to H Fritz.

At least 163 records · Page 9Linked to original sources
PubMed1985

Eglin c, a pharmacologically active elastase inhibitor.

Eglin c is an elastase/cathepsin G inhibitor from leech Hirudo medicinalis. The gene for this 70 aminoacid peptide was synthesized chemically, cloned and expressed by E. coli. Here we report biochemical and pharmacological studies. The rate of complex formation between Eglin c and human leukocyte elastase (HLE) or human cathepsin G (H. Cat. G) was determined and compared to those of a number of other proteinase/proteinase-inhibitor interactions (alpha 1 PI and alpha 2M). The association rate constants of Eglin c with the leukocyte enzymes are of the same order of magnitude as those with the naturally occurring inhibitors alpha 1 PI and alpha 2M. The association rate constant of Eglin c (extracted from leech) and Eglin c (biotechnology product) with HLE was found to be identical. The equilibrium constants Ki of the Eglin c/HLE and the Eglin c/H. Cat. G interactions are in the order of 10(-10) M. In an experiment with the hamster emphysema model, 0.5 mg or 2 mg of Eglin c applied intratracheally one hour before an HLE-insult completely protected the animals against emphysema and no signs of toxicity due to Eglin c were observed.

Animals↗
PubMed1985

Isolation and characterization of porcine alpha 1-proteinase inhibitor. Leukocyte elastase-inhibitor complexes in porcine blood, I.

alpha 1-Proteinase inhibitor was purified from porcine blood by ammonium sulphate and Cibachron Blue-Sepharose fractionation, ion exchange chromatography on DEAE-Cellulose, gel filtration on Sephadex G-25, and zinc chelating chromatography. Thus, an inhibitor preparation with a specific activity of 1.62 IU/mg protein (enzyme: trypsin; substrate: BzArgNan) was obtained. In sodium dodecyl sulphate gel electrophoresis one protein band corresponding to a molecular mass of 67.6 kDa was found. On isoelectric focusing 6 protein bands with isoelectric points of 3.80, 3.90, 4.05, 4.20, 4.25 and 4.45 were separated. The amino acid composition was determined. The association rate constants for the inhibition of various serine proteinases were measured.

Amino Acids↗
PubMed1985

Postnatal development of young rats following the treatment of the dams with sodium salicylate during late periods of pregnancy.

Female albino rats were treated with sodium salicylate dissolved in tap water orally by intubation. The first group received daily doses of 25, 75 or 150 mg/kg from day 15 through day 20 of pregnancy. The second group received daily doses of 4.2, 12.5 or 25 mg/kg on day 20 and on day 21, i.e. the day of parturition. Administration of the intermediate and high doses caused a marked increase in the mortality rates of the young animals. However, the development of the surviving young rats was similar to the controls and no change in behaviour was noted.

Animals↗
PubMed1984

The effect of kinins on paw oedema and uterus in rats.

Bradykinin (BK) produced a dose-related increase in the paw volume of the rat. Responses to BK at all doses used were not affected by pretreating the rats with diphenhydramine, 1 mg kg-1, or indomethacin, 2.5 and 5 mg kg-1. Indomethacin, 10 mg kg-1 produced a small but significant reduction in the responses to BK. Captopril 1 mg kg-1 enhanced responses to low but not to high doses of BK. The rank order of potency of various kinin analogues to increase paw volume was found to be methionyl-lysyl-BK (met-lys-BK) greater than BK greater than lysyl-BK (Kallidin) much greater than des-Arg9-BK. The B1-receptor antagonist des-Arg9-Leu8-BK did not affect responses to BK on paw volume. Two modified kinin fragments S2302 (H-D-Pro-Phe-Arg-p-Nitroaniline) and S2441 (H-D-Pro-Phe-Arg-NH-heptyl) produced dose-related increases in paw volume both having approximately half the potency of BK. These responses were not antagonised by diphenhydramine, 1 mg kg-1 which reduced significantly the response to histamine. On the isolated rat uterus the rank order of potency of various kinins was BK greater than Kallidin greater than met-lys-BK greater than des-Arg9-BK. The two modified kinin fragments S2302 and S2441 (but not des-Arg9-Leu8-BK) antagonised BK induced contractions of the rat uterus. From the rank order of potency studies the receptor mediating contraction of the rat uterus in vitro and increase in rat paw volume to BK appear to be of the same type.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

The isolation of tetrahydroxy bile acids as methyl esters from human urine and their characterization by 1H- and 13C-nuclear magnetic resonance spectroscopy.

Treatment with phenobarbital causes an increased urinary excretion of tetrahydroxylated bile acids in patients suffering from intrahepatic cholestasis. The main components were isolated from urine by means of column and thin-layer chromatography and were studied as methyl esters by nuclear magnetic resonance spectroscopy. The results obtained strongly support the contention that the main components are 1 beta-, 6 alpha- and 6 beta-hydroxylated derivatives of cholic acid.

Bile Acids and Salts↗
PubMed1984

Prenatal and postnatal development of rats following the maternal treatment with testosterone during the late period of embryogenesis.

Sprague-Dawley derived female albino rats were administered subcutaneously 0.5, 1.5, or 3.0 mg/kg of testosterone acetate in sesame oil at single daily doses, from day 13 until day 16 of pregnancy (day 0 = spermatozoa). The pregnant females were either killed shortly before term or allowed to litter and raise their offspring. Increased rates of prenatal death were observed in the three experimental groups of both these experiments. Reduced body weight of foetuses and, respectively, young rats after weaning was recorded for the intermediate and high dose groups. Embryo-lethality and delay of either foetal or postnatal development occurred at some dose-relationship and in association with slight to moderate loss of maternal body weight during the period of treatment. No teratogenic potency of testosterone was found and no changes of the female sexual organs were observed in the foetuses or young rats.

Animals↗
PubMed1983

Sequence determination of eglin C using combined microtechniques of amino acid analysis, peptide isolation, and automatic Edman degradation.

The complete amino acid sequence of a proteinase inhibitor, eglin c (Mr 8100), has been determined with less than 150 micrograms of the protein using the following microtechniques: (a) amino acid analysis with a low-nanogram amount of protein hydrolysate using dimethylaminoazobenzene sulfonyl chloride, (b) peptide isolation at the picomole level using the dimethylaminoazobenzene isothiocyanate (DABITC) precolumn derivatization method, and (c) automatic Edman degradation. One amino acid residue has been corrected for the previously reported sequence. The Contribution of each technique to the microsequencing is discussed. In addition, a new high-performance liquid chromatography system that gives a complete baseline separation of all phenylthiohydantoin-amino acids is described.

Amino Acid Sequence↗
PubMed1983

Kinin receptors and angiotensin converting enzyme in rabbits basilar arteries.

Bradykinin (BK) initially produced concentration related relaxations of the rabbit basilar artery in vitro under resting tension and when contracted with 5-hydroxytryptamine. Concentration-effect (C-E) curves to BK repeated at 2 h intervals over an 8-10 h period resulted in the production of progressively increased contractile responses. The induction of these contractile responses to BK was prevented by pre-incubation of these tissues with cycloheximide. On tissues which had been challenged with BK at 2 h intervals for 8 h in the absence of cycloheximide the rank order of potency of three kinins to produce contraction was methionyl-lysyl-BK (M-L-BK) greater than BK greater than des-Arg9-BK. On the same tissues the specific B1-receptor antagonist des-Arg9-Leu8-BK inhibited the contractile effects of BK. These results suggest the presence of a B1-receptor mediating contraction. The rank order of potency of the kinins to produce relaxation of tissues preincubated with cycloheximide was BK greater than M-L-BK greater than des-Arg9-BK which suggests the presence of a B2-receptor mediating these responses. Angiotensin I (AI) and angiotensin II (AII) produced concentration related contractions of the tissue. The angiotensin converting enzyme inhibitors captopril, BPP5a and BPP9a inhibited responses to AI but had no effect on contractile C-E curves to BK, AII and 5-HT or on relaxant C-E curves to BK. These results suggest that the rabbit basilar artery in vitro contains two BK receptors, a B1 receptor mediating contraction and a B2 receptor mediating relaxation.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiotensin I↗
PubMed1983

Protein inhibitors of cysteine proteinases. II. Primary structure of stefin, a cytosolic protein inhibitor of cysteine proteinases from human polymorphonuclear granulocytes.

The primary structure of stefin, a new cysteine proteinase inhibitor from the cytosol of human polymorphonuclear granulocytes, was determined by amino-acid sequence analysis. The protein consists of 98 amino-acid residues and contains no cysteine. Its molecular mass was calculated to be 11006 Da. The sequence was obtained by automatic solid-phase Edman degradation of the uncleaved protein and its cyanogen bromide fragments. There is no striking evidence for a sequence homology with known families of protein inhibitors of proteinases.

Amino Acid Sequence↗
PubMed1983

Intra-acrosomal inhibition of boar acrosin by synthetic proteinase inhibitors.

Thirteen serine proteinase inhibitors of the guanidine, monoamidine and diamidine type were tested for their ability to inhibit the proteinase acrosin present in the acrosome of ejaculated and capacitated boar spermatozoa. All compounds studied proved to be potent in-vitro inhibitors of acrosin. Inhibition constants (Ki) in the range of 1.2 x 10(-7) to 6 x 10(-8) M were found for the reversible inhibitors. The intra-acrosomal inhibition of acrosin was assessed by the gelatin substrate film method: 2 guanidinobenzoates, one monoamidine and one diamidine derivative proved to inhibit acrosin completely in intact spermatozoa. Intravenous injection of 6-amidino-2-(4-amidinophenyl)-indole had no effect on fertilization, but application of 4-nitrophenyl-4-guanidinobenzoate in a vaginal suppository gave a 50% reduction of fertilization.

Acrosin↗
PubMed1983

Biochemistry and applications of aprotinin, the kallikrein inhibitor from bovine organs.

The basic proteinase inhibitor from bovine organs, aprotinin (active ingredient of Trasylol) has been extensively studied with respect to its chemical, physical and biochemical properties and its inhibitory mechanism of action. It is widely used as a valuable tool for studying protein/protein interactions and protein conformation at the molecular level. There are numerous examples of the usefulness of aprotinin in biochemical and biomedical research. It has also become a valuable drug for the treatment of various diseases like, e.g. hyperfibrinolytic hemorrhage and traumatic-hemorrhagic shock. The purpose of this paper is threefold. It summarizes our present knowledge of the subject in various disciplines; it provides the active scientist with basic data for his experimental work; and above all it points the way to future directions of aprotinin research.

Animals↗