scholarly journals ACTION OF NITRO- AND HALOPHENOLS UPON OXYGEN CONSUMPTION AND PHOSPHORYLATION BY A CELL-FREE PARTICULATE SYSTEM FROM ARBACIA EGGS

1950 ◽  
Vol 33 (5) ◽  
pp. 555-561 ◽  
Author(s):  
G. H. A. Clowes ◽  
A. K. Keltch ◽  
C. F. Strittmatter ◽  
C. P. Walters
Keyword(s):  
Oxygen Consumption ◽  
Oxygen Uptake ◽  
Oxidative Phosphorylation ◽  
High Energy ◽  
Substituted Phenols ◽  
High Energy Phosphate ◽  
Particulate System ◽  
A Cell ◽  
Phosphate Groups ◽  
Stimulation Of

1. The ability of 4,6-dinitrocresol and eight other substituted phenols to stimulate oxygen uptake and inhibit phosphorylation by a cell-free particulate system from unfertilized Arbacia eggs has been determined. Five of those agents can produce both stimulation of oxygen consumption and inhibition of phosphorylation; one inhibits both oxygen consumption and phosphorylation; and two have no effect on either oxygen consumption or phosphorylation. In every case the effects of these substituted phenols upon the cell-free particulate systems parallel those upon oxygen consumption and cleavage in the intact fertilized Arbacia eggs. 2. The data suggest that energy for cleavage of the Arbacia egg is provided at least in part by oxidative phosphorylation and that substituted phenols may block cleavage by interfering with generation and transfer of high-energy phosphate groups.

scholarly journals OXIDATIVE PHOSPHORYLATION BY A CELL-FREE PARTICULATE SYSTEM FROM UNFERTILIZED ARBACIA EGGS

1950 ◽  
Vol 33 (5) ◽  
pp. 547-553 ◽  
Author(s):  
A. K. Keltch ◽  
C. F. Strittmatter ◽  
C. P. Walters ◽  
G. H. A. Clowes
Keyword(s):  
Oxidative Phosphorylation ◽  
Tricarboxylic Acid Cycle ◽  
High Energy ◽  
Equal Weight ◽  
Maximum Oxygen Consumption ◽  
Arbacia Punctulata ◽  
Particulate System ◽  
Mammalian Liver ◽  
A Cell ◽  
Ph Range

1. A cell-free particulate system capable of effecting oxidative phosphorylation has been prepared from unfertilized eggs of Arbacia punctulata. A substantial increase in phosphorylation can be produced by addition of α-ketoglutarate, oxalacetate, or succinate, the magnitude of the increase being greatest with α-ketoglutarate. The activity of the phosphorylating system is sharply dependent on maintenance of a comparatively narrow pH range during both the preparation of the particulate system and its subsequent incubation with oxidizable substrate. 2. The maximum oxygen consumption of the cell-free particulate system derived from a given weight of unfertilized eggs is about three times that of the same weight of intact unfertilized eggs and approximately the same as that of an equal weight of fertilized eggs. 3. The data indicate that generation of high-energy phosphate bonds in the Arbacia egg is coupled, as it is in mammalian liver or kidney, with the functioning of the tricarboxylic acid cycle.

Osmoregulation in surviving slices from the livers of adult rats

1952 ◽  
Vol 140 (898) ◽  
pp. 135-143 ◽  
Keyword(s):  
Oxygen Consumption ◽  
Oxygen Uptake ◽  
Water Balance ◽  
Water Content ◽  
Active Transport ◽  
High Energy ◽  
High Energy Phosphate ◽  
Adult Rats ◽  
The Media ◽  
Similar Solutions

The oxygen consumption of liver slices from adult rats was not significantly affected by the concentration of the medium when this lay between 0⋅20 and 0⋅45 osM/1. Alterations outside this range in either direction reduced the uptake of oxygen. Slices respiring at 38⋅5°C in solutions varying from 0⋅10 to 0⋅58 osm/1. always contained less water than slices in similar solutions at temperatures between 1 and 3°C. This difference was most noticeable with concentrations which did not inhibit respiration. When the oxygen uptake of slices in 0⋅30 osM media a t 38⋅5°C was inhibited by cyanide, the water content of the slices increased. Oxygen consumption increased and water content decreased again when cyanide was removed from the media. Small concentrations of 2, 4-dinitrophenol increased and larger concentrations reduced the uptake of oxygen, but both increased the amount of water in the tissue. The results suggest that the intracellular fluids are hypertonic, and that respiration governs the water balance of the tissue because some of the energy which it releases is used for active transport of water out of the cells through the mediation of compounds containing high-energy phosphate bonds. It is suggested that cloudy swelling results from a disturbance of the active transport of water.

Carotid body O2 chemoreception and mitochondrial oxidative phosphorylation

1981 ◽  
Vol 51 (2) ◽  
pp. 438-446 ◽  
Author(s):  
E. Mulligan ◽  
S. Lahiri ◽  
B. T. Storey
Keyword(s):  
Oxidative Phosphorylation ◽  
Carotid Body ◽  
High Energy ◽  
Metabolic Inhibitors ◽  
Antimycin A ◽  
Mitochondrial Oxidative Phosphorylation ◽  
High Energy Phosphate ◽  
Afferent Fibers ◽  
Carbonyl Cyanide ◽  
Stimulation Of

The effect on carotid chemoreceptor afferents of oligomycin, an inhibitor of mitochondrial oxidative phosphorylation that does not affect energy conservation, was studied in 20 cats that were anesthetized, paralyzed, and artificially ventilated. Responses of single or a few chemoreceptor afferents to changes in arterial O2 tension (PaO2) at constant arterial CO2 tension were recorded. In addition, responses to nicotine, cyanide, and antimycin A or carbonyl cyanide p-tri-fluoromethoxyphenylhydrazone (FCCP) were tested in normoxia. Oligomycin (50-500 microgram) was administered by close intra-arterial injection, and the same tests were repeated at timed intervals. Initially, oligomycin caused vigorous stimulation of carotid chemoreceptor activity. Subsequently, although the afferent fibers were still active and could be vigorously stimulated by nicotine, they no longer responded to changes in PaO2 or to doses of cyanide, antimycin A, or FCCP. These results separate stimulation of chemoreceptor afferents by hypoxia and metabolic inhibitors and uncouplers from that by nicotine and suggest that intact oxidative phosphorylation, required for maintenance of the intracellular high-energy phosphate levels, forms the basis of O2 chemoreception in the carotid body.

scholarly journals DINITROCRESOL AND PHOSPHATE STIMULATION OF THE OXYGEN CONSUMPTION OF A CELL-FREE OXIDATIVE SYSTEM OBTAINED FROM SEA URCHIN EGGS

1949 ◽  
Vol 32 (4) ◽  
pp. 503-509 ◽  
Author(s):  
Robert K. Crane ◽  
Anna K. Keltch
Keyword(s):  
Oxygen Consumption ◽  
Sea Urchin ◽  
Rabbit Kidney ◽  
Free System ◽  
Cell Free System ◽  
Sea Urchin Eggs ◽  
Equivalent Quantity ◽  
A Cell ◽  
Oxidative System ◽  
Stimulation Of

1. A cell-free system capable of using oxygen with oxalacetate as substrate has been prepared from both unfertilized and fertilized sea urchin eggs. The oxygen uptake by this system is about twice that of an equivalent quantity of intact unfertilized eggs and half that of an equivalent quantity of intact fertilized eggs. 2. The oxygen consumption of this cell-free oxidative system can be stimulated by addition of suitable concentrations of 4,6-dinitro-o-cresol or by inorganic phosphate. This confirms, with a cell-free system obtained from sea urchin eggs, the observations of Loomis and Lipmann regarding stimulation of oxygen consumption by a system obtained from rabbit kidney. 3. A preliminary but unsuccessful attempt has been made to determine the conditions under which cell-free, aerobic, phosphorylating systems may be obtained from either unfertilized or fertilized sea urchin eggs.

Absence of detectable phosphocreatine in rat luteal cells

1987 ◽  
Vol 253 (4) ◽  
pp. E391-E394 ◽  
Author(s):  
J. C. Cross ◽  
L. K. Soodak ◽  
B. Musicki ◽  
H. R. Behrman
Keyword(s):  
Specific Activity ◽  
High Energy ◽  
High Energy Phosphate ◽  
Luteal Cells ◽  
Atp Levels ◽  
Rapid Changes ◽  
Luteal Tissue ◽  
Atp Metabolism ◽  
Low Levels ◽  
Phosphate Groups

Previous studies from this laboratory showed that adenosine amplifies the action of luteinizing hormone (LH) severalfold in rat and human luteal cells by an intracellular, adenosine 5'-triphosphate (ATP)-linked process. The objective of this study was to evaluate the contribution of phosphocreatine (PCr) and creatine kinase (CK) to the dynamics of luteal ATP metabolism. Levels of PCr in luteinized rat ovaries were similar to those seen in liver but were approximately 1 and 7% of levels found in skeletal and heart muscle, respectively. In isolated rat luteal cells, little detectable PCr was seen after incubation in the presence or absence of adenosine, although cell ATP levels were increased twofold by adenosine treatment. The presence or absence of LH had no effect on either PCr or ATP levels in incubations of isolated luteal cells. Analysis of CK activity in tissue and cell homogenates showed that the specific activity of CK in luteal cells was in the same range as that seen in liver but less than 1/30 of that seen in skeletal muscle. From these studies we conclude that rat luteal cells contain little, if any, PCr and low levels of CK. Thus the rapid changes in ATP levels that are seen in rat luteal tissue and cells may occur because these cells have little capacity to buffer ATP levels with a reservoir of high-energy phosphate groups in the form of PCr.

PGE2 stimulates O2 uptake in hepatic parenchymal cells: involvement of the cAMP-dependent protein kinase

1999 ◽  
Vol 277 (5) ◽  
pp. G1048-G1054 ◽  
Author(s):  
Wei Qu ◽  
Lee M. Graves ◽  
Ronald G. Thurman
Keyword(s):  
Oxygen Consumption ◽  
Protein Kinase ◽  
Oxygen Uptake ◽  
Parenchymal Cell ◽  
Inhibitory Peptide ◽  
Dependent Protein Kinase ◽  
Camp Dependent Protein Kinase ◽  
Dependent Protein ◽  
Parenchymal Cells ◽  
Stimulation Of

The aim of this study was to determine which PGE2 receptors and signal transduction pathways are responsible for the stimulation of oxygen uptake in liver. Hepatic parenchymal cells isolated from female Sprague-Dawley rats were incubated either with PGE2, 17-phenyl-omega-trinor PGE2 (an EP1-specific agonist), or 11-deoxy PGE1 (an EP2/EP4-specific agonist), and oxygen consumption was measured. Both PGE2 and 11-deoxy PGE1 stimulated oxygen consumption. However, an EP1agonist was without effect. Although PGE2 elevated intracellular calcium, this occurred at concentrations ∼500-fold lower than that required to stimulate oxygen uptake. PGE2-stimulated increases in cAMP formation correlated well with the increase in oxygen consumption. Dibutyryl cAMP also increased oxygen consumption. Furthermore, N-[2-( p-bromocinnamylamino)ethyl]-5-isoquinolinesulfonamide, a cell-permeable inhibitor of protein kinase A (PKA), reduced the stimulation of oxygen uptake by PGE2. Incubation of isolated parenchymal cell mitochondria with the purified catalytic subunit of PKA and ATP increased both state 3 rates of oxygen uptake and the respiratory control ratio by ∼50%. Activation of these events was prevented by incubation with the PKA inhibitory peptide, PKI. These findings are consistent with the hypothesis that PGE2 stimulates oxygen consumption via an EP2 and/or EP4 subclass of receptors through the actions of cAMP on a cAMP-dependent protein kinase.

Effect of substituted phenols on movement of water and protein across the intestine

1961 ◽  
Vol 200 (2) ◽  
pp. 305-308 ◽  
Author(s):  
C. S. Tidball
Keyword(s):  
Oxygen Uptake ◽  
Oxidative Phosphorylation ◽  
Sea Urchin ◽  
Water Movement ◽  
Protein Release ◽  
Substituted Phenols ◽  
Sea Urchin Eggs

The action of three substituted phenols on intestinal net water movement in jejunal loops in situ has been studied in the anesthetized dog. The ability of these compounds to influence intestinal net water movement paralleled their previously reported ability to stimulate oxygen uptake and to produce cessation of cleavage in fertilized sea urchin eggs which are thought to be manifestation of their property to uncouple oxidative phosphorylation. Thus two effective uncouplers produced decreases in net absorption at a concentration of 1 x 10–3 m/l. and net secretion at a concentration of 1 x 10–2 m/l. A less effective uncoupler produced no change in water movement at a concentration of 1 x 10–3 m/l. and only a decrease in net absorption at a concentration of 1 x 10–2 m/l. The substituted phenols produced increases in the amount of protein which could be recovered from the lumen, but the changes in water movement produced by substituted phenols were independent of the mechanism responsible for the protein release.

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