The Experts below are selected from a list of 168 Experts worldwide ranked by ideXlab platform
Rolf L. Ingermann - One of the best experts on this subject based on the ideXlab platform.
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Ecto‐Atpase Activity of Vertebrate Blood Cells
Physiological and Biochemical Zoology, 1997Co-Authors: D.c. Bencic, Todd J. Yates, Rolf L. IngermannAbstract:ABSTRACT Ecto‐Atpase Activity was measured for red blood cells, white blood cells, and whole blood from a variety of vertebrates. A large range of red blood cell ecto‐Atpase Activity was observed; for example, at 10°C, red blood cells from a catastomid fish (Catostomus macrocheilus) and a newt (Taricha rivularis) had activities of 56 ± 9 and 25,000,000 ± 14,000,000 pmol ATP per 106 red blood cells per hour, respectively (mean ± SD). Several control experiments verified that the measured Atpase Activity was not the result of intracellular Atpases released due to cell damage or lysis nor due to the release of intracellular nucleoside triphosphate or uptake of extracellular ATP. Red blood cell ecto‐Atpase Activity was relatively low within the teleosts, was high within the reptiles, and had the greatest range and single highest value within the amphibians. Within the endotherms, avian red blood cell ecto‐Atpase activities were greater than mammalian red blood cell ecto‐Atpase activities, which were the lowes...
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ECTO-Atpase Activity OF VERTEBRATE BLOOD CELLS
Physiological and Biochemical Zoology, 1997Co-Authors: D.c. Bencic, Todd J. Yates, Rolf L. IngermannAbstract:Ecto-Atpase Activity was measured for red blood cells, white blood cells, and whole blood from a variety of vertebrates. A large range of red blood cell ecto-Atpase Activity was observed; for example, at 10 degrees C, red blood cells from a catastomid fish (Catostomus macrocheilus) and a newt (Taricha rivularis) had activities of 56 +/- 9 and 25,000,000 +/- 14,000,000 pmol ATP per 10(6) red blood cells per hour, respectively (mean +/- SD). Several control experiments verified that the measured Atpase Activity was not the result of intracellular Atpases released due to cell damage or lysis nor due to the release of intracellular nucleoside triphosphate or uptake of extracellular ATP. Red blood cell ecto-Atpase Activity was relatively low within the teleosts, was high within the reptiles, and had the greatest range and single highest value within the amphibians. Within the endotherms, avian red blood cell ecto-Atpase activities were greater than mammalian red blood cell ecto-Atpase activities, which were the lowest for all vertebrates examined. The lowest ecto-Atpase activities measured were for human and skunk red blood cells, which had activities of 13 +/- 1 and 11 +/- 2 pmol ATP per 10(6) red blood cells per hour, respectively, at 35 degrees C. Ecto-Atpase Activity was measured in white blood cells of several vertebrate species and appeared generally high and less variable than red blood cell ecto-Atpase Activity. Measured whole blood ecto-Atpase Activity showed a range of three orders of magnitude and correlated positively with red blood cell ecto-Atpase activities. Ecto-Atpase Activity was also determined for red blood cells from fetal, 1-3 d old neonatal, and pregnant garter snakes (Thamnophis elegans); these activities were not significantly different from the Activity of red blood cells from nonpregnant adult females. Overall, the data from the present study demonstrate a wide range of red blood cell and whole blood ecto-Atpase activities among vertebrates and include some of the highest ecto-Atpase activities reported to date.
D.c. Bencic - One of the best experts on this subject based on the ideXlab platform.
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Ecto‐Atpase Activity of Vertebrate Blood Cells
Physiological and Biochemical Zoology, 1997Co-Authors: D.c. Bencic, Todd J. Yates, Rolf L. IngermannAbstract:ABSTRACT Ecto‐Atpase Activity was measured for red blood cells, white blood cells, and whole blood from a variety of vertebrates. A large range of red blood cell ecto‐Atpase Activity was observed; for example, at 10°C, red blood cells from a catastomid fish (Catostomus macrocheilus) and a newt (Taricha rivularis) had activities of 56 ± 9 and 25,000,000 ± 14,000,000 pmol ATP per 106 red blood cells per hour, respectively (mean ± SD). Several control experiments verified that the measured Atpase Activity was not the result of intracellular Atpases released due to cell damage or lysis nor due to the release of intracellular nucleoside triphosphate or uptake of extracellular ATP. Red blood cell ecto‐Atpase Activity was relatively low within the teleosts, was high within the reptiles, and had the greatest range and single highest value within the amphibians. Within the endotherms, avian red blood cell ecto‐Atpase activities were greater than mammalian red blood cell ecto‐Atpase activities, which were the lowes...
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ECTO-Atpase Activity OF VERTEBRATE BLOOD CELLS
Physiological and Biochemical Zoology, 1997Co-Authors: D.c. Bencic, Todd J. Yates, Rolf L. IngermannAbstract:Ecto-Atpase Activity was measured for red blood cells, white blood cells, and whole blood from a variety of vertebrates. A large range of red blood cell ecto-Atpase Activity was observed; for example, at 10 degrees C, red blood cells from a catastomid fish (Catostomus macrocheilus) and a newt (Taricha rivularis) had activities of 56 +/- 9 and 25,000,000 +/- 14,000,000 pmol ATP per 10(6) red blood cells per hour, respectively (mean +/- SD). Several control experiments verified that the measured Atpase Activity was not the result of intracellular Atpases released due to cell damage or lysis nor due to the release of intracellular nucleoside triphosphate or uptake of extracellular ATP. Red blood cell ecto-Atpase Activity was relatively low within the teleosts, was high within the reptiles, and had the greatest range and single highest value within the amphibians. Within the endotherms, avian red blood cell ecto-Atpase activities were greater than mammalian red blood cell ecto-Atpase activities, which were the lowest for all vertebrates examined. The lowest ecto-Atpase activities measured were for human and skunk red blood cells, which had activities of 13 +/- 1 and 11 +/- 2 pmol ATP per 10(6) red blood cells per hour, respectively, at 35 degrees C. Ecto-Atpase Activity was measured in white blood cells of several vertebrate species and appeared generally high and less variable than red blood cell ecto-Atpase Activity. Measured whole blood ecto-Atpase Activity showed a range of three orders of magnitude and correlated positively with red blood cell ecto-Atpase activities. Ecto-Atpase Activity was also determined for red blood cells from fetal, 1-3 d old neonatal, and pregnant garter snakes (Thamnophis elegans); these activities were not significantly different from the Activity of red blood cells from nonpregnant adult females. Overall, the data from the present study demonstrate a wide range of red blood cell and whole blood ecto-Atpase activities among vertebrates and include some of the highest ecto-Atpase activities reported to date.
Todd J. Yates - One of the best experts on this subject based on the ideXlab platform.
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Ecto‐Atpase Activity of Vertebrate Blood Cells
Physiological and Biochemical Zoology, 1997Co-Authors: D.c. Bencic, Todd J. Yates, Rolf L. IngermannAbstract:ABSTRACT Ecto‐Atpase Activity was measured for red blood cells, white blood cells, and whole blood from a variety of vertebrates. A large range of red blood cell ecto‐Atpase Activity was observed; for example, at 10°C, red blood cells from a catastomid fish (Catostomus macrocheilus) and a newt (Taricha rivularis) had activities of 56 ± 9 and 25,000,000 ± 14,000,000 pmol ATP per 106 red blood cells per hour, respectively (mean ± SD). Several control experiments verified that the measured Atpase Activity was not the result of intracellular Atpases released due to cell damage or lysis nor due to the release of intracellular nucleoside triphosphate or uptake of extracellular ATP. Red blood cell ecto‐Atpase Activity was relatively low within the teleosts, was high within the reptiles, and had the greatest range and single highest value within the amphibians. Within the endotherms, avian red blood cell ecto‐Atpase activities were greater than mammalian red blood cell ecto‐Atpase activities, which were the lowes...
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ECTO-Atpase Activity OF VERTEBRATE BLOOD CELLS
Physiological and Biochemical Zoology, 1997Co-Authors: D.c. Bencic, Todd J. Yates, Rolf L. IngermannAbstract:Ecto-Atpase Activity was measured for red blood cells, white blood cells, and whole blood from a variety of vertebrates. A large range of red blood cell ecto-Atpase Activity was observed; for example, at 10 degrees C, red blood cells from a catastomid fish (Catostomus macrocheilus) and a newt (Taricha rivularis) had activities of 56 +/- 9 and 25,000,000 +/- 14,000,000 pmol ATP per 10(6) red blood cells per hour, respectively (mean +/- SD). Several control experiments verified that the measured Atpase Activity was not the result of intracellular Atpases released due to cell damage or lysis nor due to the release of intracellular nucleoside triphosphate or uptake of extracellular ATP. Red blood cell ecto-Atpase Activity was relatively low within the teleosts, was high within the reptiles, and had the greatest range and single highest value within the amphibians. Within the endotherms, avian red blood cell ecto-Atpase activities were greater than mammalian red blood cell ecto-Atpase activities, which were the lowest for all vertebrates examined. The lowest ecto-Atpase activities measured were for human and skunk red blood cells, which had activities of 13 +/- 1 and 11 +/- 2 pmol ATP per 10(6) red blood cells per hour, respectively, at 35 degrees C. Ecto-Atpase Activity was measured in white blood cells of several vertebrate species and appeared generally high and less variable than red blood cell ecto-Atpase Activity. Measured whole blood ecto-Atpase Activity showed a range of three orders of magnitude and correlated positively with red blood cell ecto-Atpase activities. Ecto-Atpase Activity was also determined for red blood cells from fetal, 1-3 d old neonatal, and pregnant garter snakes (Thamnophis elegans); these activities were not significantly different from the Activity of red blood cells from nonpregnant adult females. Overall, the data from the present study demonstrate a wide range of red blood cell and whole blood ecto-Atpase activities among vertebrates and include some of the highest ecto-Atpase activities reported to date.
Yasuo Ogawa - One of the best experts on this subject based on the ideXlab platform.
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Discrimination of Ca2+-Atpase Activity of the sarcoplasmic reticulum from actomyosin-type Atpase Activity of myofibrils in skinned mammalian skeletal muscle fibres: distinct effects of cyclopiazonic acid on the two Atpase activities
Journal of muscle research and cell motility, 1991Co-Authors: Nagomi Kurebayashi, Yasuo OgawaAbstract:We have developed a procedure to discriminate actomyosin-type Atpase Activity from Ca2+-Atpase Activity of sarcoplasmic reticulum (SR) in mechanically skinned fibres, determining simultaneously their Ca2+-induced tension and accompanying Atpase Activity. When they were treated with an alkaline CyDTA-containing solution of low ionic strength which was reported to remove troponin C, the fibres showed a considerable amount of Ca2+-dependent Atpase Activity, in spite of having little or no Ca2+-induced isometric tension. The residual Atpase Activity is ascribed to the Ca2+-Atpase Activity of SR, because it is completely abolished by 1% CHAPS treatment for 10 min. This conclusion is also supported by the finding that the Ca2+-dependence of the Atpase Activity is very similar to that of Ca2+-Atpase of SR isolated from rabbit skeletal muscle, and that the estimated Activity is consistent with the reported values of direct determinations. On the other hand, treatment with a detergent such as CHAPS or Triton X-100 removes SR activities (Atpase and Ca-uptake), leaving Ca2+-induced tension and actomyosin-type Atpase Activity unchanged. This procedure indicated that the contribution of Ca2+-Atpase Activity of SR may be minimal in total steady-state Atpase Activity of mechanically skinned mammalian skeletal muscle fibres. Successive CyDTA and CHAPS treatments eliminated both Ca2+-induced tension and Atpase Activity, which were recovered by the addition of troponin C. Using these procedures, we also examined the effect of cyclopiazonic acid (CPA) which was reported to be a specific inhibitor of Ca2+-Atpase of SR. Ca2+-Atpase Activity of SR in skinned fibres was inhibited completely by 10 μm CPA and held to one-half by about 0.2 μm. This effect was only partially reversible. CPA at 10μm or higher concentrations showed Ca2+-sensitizing action on myofibrils, which was readily reversible. CPA at 3μm inhibited almost completely the Ca2+-Atpase Activity of SR, while it had no effect on either actomyosin-type Atpase or isometric tension of myofibrils.
Alicia Megías - One of the best experts on this subject based on the ideXlab platform.
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Measurement of Sarcoplasmic Reticulum Ca2+-Atpase Activity and E-Type Mg2+-Atpase Activity in Rat Heart Homogenates☆
Analytical biochemistry, 1999Co-Authors: Ana Saborido, Jerónimo Delgado, Alicia MegíasAbstract:The presence of a high and nonlinear Ca2+-independent (or basal) Atpase Activity in rat heart preparations makes difficult the reliable measurement of sarcoplasmic reticulum (SR) Ca2+-Atpase Activity by usual methods. A spectrophotometric assay for the accurate determination of SR Ca2+-Atpase Activity in unfractionated homogenates from rat heart is described. The procedure is based on that reported by Simonides and van Hardeveld (1990, Anal. Biochem. 191, 321-331) for skeletal muscle homogenates. To avoid overestimation of the Ca2+-Atpase Activity of cardiac homogenates that occurs when sequential measurements of total and basal Atpase activities are performed, two parallel and independent assays are required: one with low (micromolar) and other high (millimolar) calcium concentration. Addition of thapsigargin (0.2 microM) blocked totally the Activity considered as Ca2+-Atpase Activity. Using this method, the rat heart homogenate Ca2+-Atpase Activity was 10.5 +/- 2.0 micromol. min-1 x g-1 tissue wet weight (n = 8). Likewise, a spectrophotometric assay for measuring E-type Mg2+-Atpase Activity in cardiac total homogenates has been developed, comparing the following characteristics of the enzymatic Activity in homogenate and a membrane-enriched fraction: first-order rate constant for ATP-dependent inactivation, Km for ATP, and effects of concanavalin A, Triton X-100, and specific inhibitors.