The Experts below are selected from a list of 237 Experts worldwide ranked by ideXlab platform
John R. Vane - One of the best experts on this subject based on the ideXlab platform.
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Characterization of serine protease-derived metabolites of big endothelin in the Cytosolic Fraction from human polymorphonuclear leukocytes.
Journal of Cardiovascular Pharmacology, 1992Co-Authors: Semiko Kaw, Markus Hecker, Garry J. Southan, Timothy D. Warner, John R. VaneAbstract:We have characterized by bioassay and reversed-phase high-performance liquid chromatography analysis (rp-HPLC) the conversion of human big endothelin-1 (bET-1) to endothelin-1 (ET-1) by the Cytosolic Fraction from human polymorphonuclear leukocytes (PMNs). Either the general serine protease inhibitor 3,4-dichloroisocoumarin (DCI; 50 μM) or the selective elastase inhibitor ONO-5046 (100 μM) blocked the formation of ET-1 from bET-1
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Characterization of serine protease-derived metabolites of big endothelin in the Cytosolic Fraction from human polymorphonuclear leukocytes.
Journal of cardiovascular pharmacology, 1992Co-Authors: Semiko Kaw, Markus Hecker, Garry J. Southan, Timothy D. Warner, John R. VaneAbstract:We have characterized by bioassay and reversed-phase high-performance liquid chromatography analysis (rp-HPLC) the conversion of human big endothelin-1 (bET-1) to endothelin-1 (ET-1) by the Cytosolic Fraction from human polymorphonuclear leukocytes (PMNs). Either the general serine protease inhibitor 3,4-dichloroisocoumarin (DCI; 50 microM) or the selective elastase inhibitor ONO-5046 (100 microM) blocked the formation of ET-1 from bET-1. Interestingly, human leukocyte elastase formed some of the same products from bET-1 as the PMN cytosol, but generated negligible amounts of ET-1. However, coincubation of the elastase-derived fragments of bET-1 with the PMN cytosol in the presence of ONO-5046 resulted in a 17-fold increase in the formation of ET-1, indicating that an elastase-derived intermediate of bET-1 was subsequently cleaved by a soluble protease(s) to form mature ET-1. We have identified by electrospray-mass spectrometry (ESMS) analysis this intermediate as bET-1(1-22). Analysis of bET-1 digestion by human leukocyte cathepsin G revealed the formation of a biologically active metabolite chromatographically distinct from ET-1, identified as bET-1(1-31) by ESMS. These findings indicate the presence of complex enzyme systems in human PMNs capable of activating bET-1.
Øystein Andresen - One of the best experts on this subject based on the ideXlab platform.
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Studies on 5α-androst-16-en-3-one binding to porcine serum, plasma and testicular Cytosolic Fraction and to human serum
The Journal of Steroid Biochemistry and Molecular Biology, 2008Co-Authors: Galia Zamaratskaia, Ellen Dahl, Andrzej Madej, E. James Squires, Øystein AndresenAbstract:The present study evaluated whether a specific androstenone-binding protein is present in porcine and human serum, and in the Cytosolic Fraction of porcine testis. The binding of [(3)H]-androstenone to serum and testicular cytosol was measured in the absence (total binding) and presence (non-specific binding) of unlabelled androstenone. The optimization of the assay is described. As a part of the assay validation, the binding of [(3)H]-dihydrotestosterone ([(3)H]-DHT) to porcine and human serum was also examined. As expected, specific binding of [(3)H]-DHT was detected in human serum, but not in porcine serum. No specific androstenone-binding protein was detected, either in porcine or human serum, or in the Cytosolic Fraction of porcine testis. The amount of non-specific binding of [(3)H]-androstenone was slightly lower in porcine serum compared to human serum. Between-animal variations in [(3)H]-androstenone binding were studied in plasma samples from 15 animals with androstenone concentrations ranging from 1.1 to 23.1 ng/mL. Mean values+/-standard deviations of binding in these samples were 15.2+/-0.9% for total binding and 15.9+/-0.8% for non-specific bindings. Low between-animal variations indicate that androstenone binding does not affect androstenone accumulation in fat.
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Studies on 5alpha-androst-16-en-3-one binding to porcine serum, plasma and testicular Cytosolic Fraction and to human serum.
The Journal of steroid biochemistry and molecular biology, 2008Co-Authors: Galia Zamaratskaia, Ellen Dahl, Andrzej Madej, E. James Squires, Øystein AndresenAbstract:The present study evaluated whether a specific androstenone-binding protein is present in porcine and human serum, and in the Cytosolic Fraction of porcine testis. The binding of [(3)H]-androstenone to serum and testicular cytosol was measured in the absence (total binding) and presence (non-specific binding) of unlabelled androstenone. The optimization of the assay is described. As a part of the assay validation, the binding of [(3)H]-dihydrotestosterone ([(3)H]-DHT) to porcine and human serum was also examined. As expected, specific binding of [(3)H]-DHT was detected in human serum, but not in porcine serum. No specific androstenone-binding protein was detected, either in porcine or human serum, or in the Cytosolic Fraction of porcine testis. The amount of non-specific binding of [(3)H]-androstenone was slightly lower in porcine serum compared to human serum. Between-animal variations in [(3)H]-androstenone binding were studied in plasma samples from 15 animals with androstenone concentrations ranging from 1.1 to 23.1 ng/mL. Mean values+/-standard deviations of binding in these samples were 15.2+/-0.9% for total binding and 15.9+/-0.8% for non-specific bindings. Low between-animal variations indicate that androstenone binding does not affect androstenone accumulation in fat.
Semiko Kaw - One of the best experts on this subject based on the ideXlab platform.
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Characterization of serine protease-derived metabolites of big endothelin in the Cytosolic Fraction from human polymorphonuclear leukocytes.
Journal of Cardiovascular Pharmacology, 1992Co-Authors: Semiko Kaw, Markus Hecker, Garry J. Southan, Timothy D. Warner, John R. VaneAbstract:We have characterized by bioassay and reversed-phase high-performance liquid chromatography analysis (rp-HPLC) the conversion of human big endothelin-1 (bET-1) to endothelin-1 (ET-1) by the Cytosolic Fraction from human polymorphonuclear leukocytes (PMNs). Either the general serine protease inhibitor 3,4-dichloroisocoumarin (DCI; 50 μM) or the selective elastase inhibitor ONO-5046 (100 μM) blocked the formation of ET-1 from bET-1
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Characterization of serine protease-derived metabolites of big endothelin in the Cytosolic Fraction from human polymorphonuclear leukocytes.
Journal of cardiovascular pharmacology, 1992Co-Authors: Semiko Kaw, Markus Hecker, Garry J. Southan, Timothy D. Warner, John R. VaneAbstract:We have characterized by bioassay and reversed-phase high-performance liquid chromatography analysis (rp-HPLC) the conversion of human big endothelin-1 (bET-1) to endothelin-1 (ET-1) by the Cytosolic Fraction from human polymorphonuclear leukocytes (PMNs). Either the general serine protease inhibitor 3,4-dichloroisocoumarin (DCI; 50 microM) or the selective elastase inhibitor ONO-5046 (100 microM) blocked the formation of ET-1 from bET-1. Interestingly, human leukocyte elastase formed some of the same products from bET-1 as the PMN cytosol, but generated negligible amounts of ET-1. However, coincubation of the elastase-derived fragments of bET-1 with the PMN cytosol in the presence of ONO-5046 resulted in a 17-fold increase in the formation of ET-1, indicating that an elastase-derived intermediate of bET-1 was subsequently cleaved by a soluble protease(s) to form mature ET-1. We have identified by electrospray-mass spectrometry (ESMS) analysis this intermediate as bET-1(1-22). Analysis of bET-1 digestion by human leukocyte cathepsin G revealed the formation of a biologically active metabolite chromatographically distinct from ET-1, identified as bET-1(1-31) by ESMS. These findings indicate the presence of complex enzyme systems in human PMNs capable of activating bET-1.
Gustav Dallner - One of the best experts on this subject based on the ideXlab platform.
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Biosynthesis of trans,trans,trans-geranylgeranyl diphosphate by the Cytosolic Fraction from rat tissues.
Biochemical and biophysical research communications, 1992Co-Authors: M. Runquist, Johan Ericsson, Anders Thelin, Tadeusz Chojnacki, Gustav DallnerAbstract:The Cytosolic Fractions from rat liver, brain, kidney, spleen and testis demonstrate the capacity to synthesize two products from [3H]isopentenyl diphosphate, i.e., farnesyl diphosphate and geranylgeranyl diphosphate. The highest rate of geranylgeranyl diphosphate synthesis was found in brain, testis and spleen, accounting for up to 30% of the total incorporation of radioactivity under optimal conditions. In all tissues examined the geranylgeranyl diphosphate formed was identified as the trans,trans,trans-isomer. The ratio of geranylgeranyl diphosphate to farnesyl diphosphate produced was specific for the tissue investigated and could be altered by the addition of divalent cations. The results in this study demonstrate the presence of a specific trans,trans,trans-geranylgeranyl diphosphate synthetase showing high affinity for farnesyl diphosphate.
Galia Zamaratskaia - One of the best experts on this subject based on the ideXlab platform.
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Studies on 5α-androst-16-en-3-one binding to porcine serum, plasma and testicular Cytosolic Fraction and to human serum
The Journal of Steroid Biochemistry and Molecular Biology, 2008Co-Authors: Galia Zamaratskaia, Ellen Dahl, Andrzej Madej, E. James Squires, Øystein AndresenAbstract:The present study evaluated whether a specific androstenone-binding protein is present in porcine and human serum, and in the Cytosolic Fraction of porcine testis. The binding of [(3)H]-androstenone to serum and testicular cytosol was measured in the absence (total binding) and presence (non-specific binding) of unlabelled androstenone. The optimization of the assay is described. As a part of the assay validation, the binding of [(3)H]-dihydrotestosterone ([(3)H]-DHT) to porcine and human serum was also examined. As expected, specific binding of [(3)H]-DHT was detected in human serum, but not in porcine serum. No specific androstenone-binding protein was detected, either in porcine or human serum, or in the Cytosolic Fraction of porcine testis. The amount of non-specific binding of [(3)H]-androstenone was slightly lower in porcine serum compared to human serum. Between-animal variations in [(3)H]-androstenone binding were studied in plasma samples from 15 animals with androstenone concentrations ranging from 1.1 to 23.1 ng/mL. Mean values+/-standard deviations of binding in these samples were 15.2+/-0.9% for total binding and 15.9+/-0.8% for non-specific bindings. Low between-animal variations indicate that androstenone binding does not affect androstenone accumulation in fat.
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Studies on 5alpha-androst-16-en-3-one binding to porcine serum, plasma and testicular Cytosolic Fraction and to human serum.
The Journal of steroid biochemistry and molecular biology, 2008Co-Authors: Galia Zamaratskaia, Ellen Dahl, Andrzej Madej, E. James Squires, Øystein AndresenAbstract:The present study evaluated whether a specific androstenone-binding protein is present in porcine and human serum, and in the Cytosolic Fraction of porcine testis. The binding of [(3)H]-androstenone to serum and testicular cytosol was measured in the absence (total binding) and presence (non-specific binding) of unlabelled androstenone. The optimization of the assay is described. As a part of the assay validation, the binding of [(3)H]-dihydrotestosterone ([(3)H]-DHT) to porcine and human serum was also examined. As expected, specific binding of [(3)H]-DHT was detected in human serum, but not in porcine serum. No specific androstenone-binding protein was detected, either in porcine or human serum, or in the Cytosolic Fraction of porcine testis. The amount of non-specific binding of [(3)H]-androstenone was slightly lower in porcine serum compared to human serum. Between-animal variations in [(3)H]-androstenone binding were studied in plasma samples from 15 animals with androstenone concentrations ranging from 1.1 to 23.1 ng/mL. Mean values+/-standard deviations of binding in these samples were 15.2+/-0.9% for total binding and 15.9+/-0.8% for non-specific bindings. Low between-animal variations indicate that androstenone binding does not affect androstenone accumulation in fat.
