PHOSPHORYLATION COUPLED TO THE OXIDATION OF SULFITE AND 2-MERCAPTOETHANOL IN EXTRACTS OF THIOBACILLUS THIOPARUS

1967 ◽  
Vol 13 (7) ◽  
pp. 873-884 ◽  
Author(s):  
E. A. Davis ◽  
E. J. Johnson
Keyword(s):  
Electron Donor ◽  
Adenosine Monophosphate ◽  
Adenosine Diphosphate ◽  
High Energy ◽  
High Energy Phosphate ◽  
Thiobacillus Thioparus ◽  
Ph Values ◽  
Cell Extracts ◽  
Endogenous Level ◽  
Sulfite Oxidation

The effect of 10−4 M 2, 4-dinitrophenol (DNP) on the production of high energy phosphate bonds during sulfite and 2-mercaptoethanol (2-ME) oxidation by cell extracts of Thiobacillus thioparus was determined. Phosphorylation was measured indirectly by14CO2fixation and directly by32PO4esterification. DNP-sensitive phosphorylation was demonstrated by coupling sulfite oxidation with the concomitant phosphorylation of adenosine monophosphate (AMP) to14CO2fixation beginning with ribose-5-phosphate. Esterification of32PO4was measured at pH values of 6.4, 7.2, and 8.0 with AMP and adenosine diphosphate (ADP) as the phosphate acceptor and sulfite as the electron donor. The optimal pH for the greatest DNP-sensitive phosphorylation was 7.2 with AMP. DNP at 10−4 M significantly reduced32PO4esterification at all pH values tested and with the three ADP concentrations employed. Maximum DNP-sensitive phosphorylation of ADP was demonstrated with 5 μmoles of ADP at pH 7.2. The maximum P:O ratio was 0.13. With 2-ME as the nonphysiological electron donor and AMP as the phosphate acceptor, no phosphorylation above the endogenous level was measured at the three pH values tested. With ADP as the phosphate acceptor and 2-ME as the electron donor,32PO4esterification significantly above the endogenous level was demonstrated at pH 6.4 with 5 μmoles of ADP; this phosphorylation was sensitive to 10−4 M DNP.

High-energy phosphate levels in the cerebral artery during chronic vasospasm after subarachnoid hemorrhage

1992 ◽  
Vol 76 (6) ◽  
pp. 991-996 ◽  
Author(s):  
Phyo Kim ◽  
James D. Jones ◽  
Thoralf M. Sundt
Keyword(s):  
Subarachnoid Hemorrhage ◽  
Cerebral Artery ◽  
High Performance ◽  
Venous Blood ◽  
Adenosine Monophosphate ◽  
Adenosine Diphosphate ◽  
High Energy ◽  
High Energy Phosphate ◽  
Content Type ◽  
Chronic Vasospasm

✓ High-energy phosphate levels were measured in the canine cerebral artery during chronic vasospasm. Subarachnoid hemorrhage and vasospasm were induced by percutaneous injections of autologous venous blood into the cisterna magna. Narrowing of the artery was confirmed by angiography 7 days later. Levels of adenosine phosphates (adenosine triphosphate (ATP), adenosine diphosphate (ADP), and adenosine monophosphate (AMP)), guanosine phosphates (guanosine triphosphate (GTP) and guanosine diphosphate (GDP)), and creatine phosphate (CrP) in the basilar artery were quantified using high-performance liquid chromatography. The total creatine (Crtotal) content was measured by a spectrophotometric method after acid hydrolysis of CrP. Levels of ATP, GTP, and CrP were markedly reduced in the spastic arteries, and ratios of ATP:ADP, GTP:GDP, and CrP:Crtotal were significantly decreased. The results indicate a serious disturbance in the energy metabolism that takes place in the cerebral artery during chronic vasospasm.

THE INFLUENCE OF SYMPATHOMIMETIC AMINES, MONOAMINE OXIDASE INHIBITORS, AND ANTIHYPERTENSIVES UPON THE ENERGY METABOLISM IN THE RAT HEART

1966 ◽  
Vol 44 (4) ◽  
pp. 605-613 ◽  
Author(s):  
W. G. Hilliard ◽  
W. T. Oliver ◽  
G. R. Van Petten
Keyword(s):  
Energy Metabolism ◽  
Monoamine Oxidase ◽  
Rat Heart ◽  
Antihypertensive Drugs ◽  
Adenosine Monophosphate ◽  
Adenosine Diphosphate ◽  
High Energy ◽  
Monoamine Oxidase Inhibitors ◽  
Sympathomimetic Amines ◽  
Cardiac Energy Metabolism

This investigation was undertaken to determine the effects of three classes of catecholamine-releasing drugs on cardiac energy metabolism. The levels of adenosine monophosphate (AMP), adenosine diphosphate (ADP), adenosine triphosphate (ATP), inorganic phosphate (IP), and phosphocreatine (CP) of the rat heart were measured. The sympathomimetic amines tyramine, ephedrine, methylamphetamine, and (+)- and (−)-amphetamine caused significant decreases in CP. Tyramine and (+)- and (−)-amphetamine also significantly depressed ATP. Of the antihypertensive drugs investigated, bretylium and guanethidine decreased the amount of CP present, and the latter compound also significantly decreased ATP. The administration of reserpine was without significant effect on cardiac high-energy phosphate levels. Among the monoamine oxidase inhibitors, tranylcypromine significantly lowered ATP and CP, whereas pheniprazine produced no significant changes. This study showed that those drugs which have been reported to release cardiac catecholamines also reduced cardiac levels of CP and ATP. The hypothesis is advanced that this effect is due to increased utilization of energy by two mechanisms: (a) stimulation of the active recapture mechanism for adrenergic neurotransmitters, and (b) the positive inotropic and chronotropic responses of the heart to the drug-released catecholamines. In either case, the observed decreases in the levels of ATP and CP in the heart are effects of sympathomimetic amines which have been heretofore unreported.

EVALUATION OF THE ENERGY GAINED BY PSEUDOMONAS AERUGINOSA DURING THE OXIDATION OF GLUCOSE TO 2-KETOGLUCONATE

1956 ◽  
Vol 2 (3) ◽  
pp. 304-309 ◽  
Author(s):  
J. J. R. Campbell ◽  
T. Ramakrishnan ◽  
A. G. Linnes ◽  
B. A. Eagles
Keyword(s):  
Pseudomonas Aeruginosa ◽  
High Energy ◽  
High Energy Phosphate ◽  
Cell Extracts ◽  
Gain Energy ◽  
Oxidation Of Glucose ◽  
Theoretical Amount

Cell extracts of Pseudomonas aeruginosa were shown to oxidize glucose with the accumulation of 2-ketogluconate. The theoretical amount of oxygen was taken up during the reaction and no added hydrogen acceptors were necessary. With glucose as substrate these extracts did not form high energy phosphate nor did they reduce diphosphopyridine nucleotide or triphosphopyridine nucleotide. Almost identical amounts of growth were obtained when limiting equimolar amounts of glucose, gluconate, or 2-ketogluconate were compared as sole sources of carbon. It was concluded that P. aeruginosa 9027 does not gain energy during the oxidative steps glucose –→ gluconate –→ 2-ketogluconate.

INFLUENCES OF THYROXINE AND INSULIN ON THE TURNOVER AND FATE OF HIGH-ENERGY PHOSPHATE

1964 ◽  
Vol 42 (6) ◽  
pp. 777-786 ◽  
Author(s):  
Dorothy S. Dow
Keyword(s):  
Skeletal Muscle ◽  
Energy Transfer ◽  
Adenosine Triphosphate ◽  
Cell Structure ◽  
Adenosine Diphosphate ◽  
High Energy ◽  
High Energy Phosphate ◽  
Nucleoside Phosphorylase ◽  
Mitochondrial Permeability ◽  
Energy Acceptor

Ingestion by the weanling rat of thyroxine in an amount greatly in excess of physiological requirements resulted in significant increases in the rates of turnover of the high-energy compounds phosphocreatine (PC), adenosine diphosphate (ADP), and adenosine triphosphate (ATP) and in significant decreases in their concentrations in skeletal muscle. Nucleoside phosphorylase and myokinase activities and rates of pyrophosphate splitting of ATP and of utilization of ATP for nuclear syntheses were unaltered in thyrotoxic muscle. The findings suggest that increased extramitochondrial utilization of ATP for glycolysis may be the factor responsible for the increased phosphorylating capacity of the thyrotoxic animal. An effect of thyroxine on mitochondrial permeability as well as on rate of formation of the high-energy intermediate would appear to explain the observed results.A further enhancement of the already markedly elevated thyrotoxic rate of phosphorylation was effected by the superimposition of insulin. Insulin also effected increases in the concentrations of the high-energy compounds. It is apparent that insulin acts by reducing the utilization of ATP for phosphorylation of glucose and thus increases the mitochondrial availability of high-energy acceptor. This increased mitochondrial affinity for high-energy compounds results in an enhancement of mitochondrial energy transfer processes.The findings appear to involve both thyroxine and insulin in the control of cell structure.

Temporal profile and significance of metabolic failure and trophic changes in the canine cerebral arteries during chronic vasospasm after subarachnoid hemorrhage

1993 ◽  
Vol 78 (5) ◽  
pp. 807-812 ◽  
Author(s):  
Yuhei Yoshimoto ◽  
Phyo Kim ◽  
Tomio Sasaki ◽  
Kintomo Takakura
Keyword(s):  
Subarachnoid Hemorrhage ◽  
High Performance ◽  
Close Association ◽  
Cerebral Arteries ◽  
Adenosine Monophosphate ◽  
Adenosine Diphosphate ◽  
High Energy ◽  
High Energy Phosphates ◽  
Content Type ◽  
Temporal Profile

✓ To investigate the pathogenetic significance of metabolic failure observed in spastic cerebral arteries after subarachnoid hemorrhage (SAH), the temporal profile of alterations in the arterial content of high-energy phosphates was studied. A canine model of double hemorrhage was used. Constriction of the basilar artery was measured angiographically on Days 3, 5, 7, and 14 after SAH in separate groups of animals. Adenosine triphosphate (ATP), adenosine diphosphate (ADP), adenosine monophosphate (AMP), guanosine triphosphate (GTP), guanosine diphosphate, creatine phosphate (CrP), and creatine (Cr) levels in the arteries were assayed using high-performance liquid chromatography. A time-dependent development of angiographic spasm was confirmed. A mild vasospasm was seen in the group studied 3 days after SAH, progressed in the Day 5 group, remained comparably severe in the Day 7 group, and resolved partially in the Day 14 group. The content of high-energy phosphates (ATP, GTP, and CrP) declined rapidly over the course of the study, and a significant reduction in ATP, GTP, and CrP was observed in the Day 3 group. Levels of ATP and CrP decreased further in the Day 5 and 7 groups. The decrement in GTP was completed in the early phase; a significant reduction took place in the Day 3 group, with no progression thereafter and no recovery though Day 14. Total adenylate (ATP + ADP + AMP) and total creatine (Cr + CrP) content diminished markedly over the course of the study. These results indicate that metabolic failure and trophic disturbance in the cerebral artery occurs with a rapid onset following SAH and progresses in close association with the development of vasospasm, suggesting a significant causal relationship with the pathogenesis.

A note on the effect of stocking density and temperature on meat quality in pigs

1989 ◽  
Vol 48 (2) ◽  
pp. 480-482 ◽  
Author(s):  
H. J. Guise ◽  
P. D. Warriss
Keyword(s):  
Meat Quality ◽  
Stocking Density ◽  
Live Weight ◽  
High Energy ◽  
Glycogen Depletion ◽  
High Energy Phosphate ◽  
Large White ◽  
Ambient Temperatures ◽  
Ph Values ◽  
R Value

One hundred and eighty-four Large White × Landrace pigs were transported 192 km to slaughter at stocking densities of either 0·3 or 0·4 m2 per 100 kg live weight and at ambient temperatures of >14°C or <10°C. After holding for 3 h in lairage and slaughter by normal practices, samples of m. semimembranosus were removed 45 min after exsanguination. Overall, pigs transported under cold conditions had a slightly lower mean pH45 (0·12 difference, P < 0·05) in the muscle but there were no effects of treatment on ultimate pH or R-value, a measure of the ratio of high energy phosphate compounds to their metabolites. Over 11% of the pigs had ultimate pH values 5·9. This may imply that the pre-slaughter handling had led to some material glycogen depletion. In view of the lack of major effects of stocking density or temperature during transport, it is likely that factors other than the treatments were contributors to this condition and were more important in determining subsequent meat quality.

INFLUENCE OF INGESTED CASEIN HYDROLYZATE ON THE HIGH ENERGY NUCLEOTIDE CONTENT OF WORKING MUSCLE

1963 ◽  
Vol 41 (1) ◽  
pp. 1531-1536
Author(s):  
J. M. Afar ◽  
V. A. Rogozkin
Keyword(s):  
Amino Acids ◽  
Phosphoric Acid ◽  
Low Temperatures ◽  
Muscular Activity ◽  
Adenosine Monophosphate ◽  
Adenosine Diphosphate ◽  
High Energy ◽  
Albino Rats ◽  
Phosphate Ester ◽  
Casein Hydrolyzate

The results of experiments carried out on albino rats show that administration, during periods of continued muscular activity, of casein hydrolyzate, a mixture of amino acids, or phosphoric acid salts, favors the maintenance of a higher than normal level of adenosine triphosphate (ATP) and phosphocreatine (CP) and a corresponding decrease in the level of adenosine diphosphate (ADP) and adenosine monophosphate (AMP) in the muscles.It appears from this study that just as carbohydrate is known to have a protein-sparing action, so amino acids have been found to have a sparing action in the metabolism of carbohydrate and phosphate ester in the animal even under conditions of intense physical exercise at low temperatures.

Regional cortical metabolism in focal ischemia

1980 ◽  
Vol 52 (6) ◽  
pp. 755-763 ◽  
Author(s):  
Robert A. Ratcheson ◽  
James A. Ferrendelli
Keyword(s):  
Interindividual Variability ◽  
Adenosine Monophosphate ◽  
Adenosine Diphosphate ◽  
High Energy ◽  
Focal Ischemia ◽  
Metabolic Changes ◽  
High Energy Phosphates ◽  
Cerebral Vessel ◽  
Content Type ◽  
Glucose Levels

✓ Regional cortical levels of organic phosphates and carbohydrates were measured in cat brains, enzymatically inactivated by the technique of “funnel freezing” 1 hour after occlusion of a middle cerebral artery (MCA). Significant metabolic alterations occurred in all hemispheres ipsilateral to the site of occlusion. However, there was marked interindividual variability, with changes ranging from only slight increases in lactate, pyruvate, and adenosine monophosphate (AMP) in small regions of cortex at one extreme, to profound depletion of high-energy phosphates, depression of glucose and pyruvate levels, and increased lactate, adenosine diphosphate (ADP) and AMP levels in much of the hemisphere of the most severely involved animals. In contrast, metabolic changes in the hemisphere contralateral to the site of occlusion were very few or nonexistent. In addition, in all ipsilateral hemispheres there were regions peripheral to the areas of greatest metabolic alteration where there was excessive elevation of glucose levels. The results demonstrate that occlusion of a major cerebral vessel does not produce metabolic changes that are consistent in their distribution or severity. However, the findings of this study probably depict some of the complicated metabolic events that occur clinically during thrombotic or embolic infarction of brain.

INFLUENCE OF INGESTED CASEIN HYDROLYZATE ON THE HIGH ENERGY NUCLEOTIDE CONTENT OF WORKING MUSCLE

1963 ◽  
Vol 41 (7) ◽  
pp. 1531-1536
Author(s):  
J. M. Afar ◽  
V. A. Rogozkin
Keyword(s):  
Amino Acids ◽  
Phosphoric Acid ◽  
Low Temperatures ◽  
Muscular Activity ◽  
Adenosine Monophosphate ◽  
Adenosine Diphosphate ◽  
High Energy ◽  
Albino Rats ◽  
Phosphate Ester ◽  
Casein Hydrolyzate

The results of experiments carried out on albino rats show that administration, during periods of continued muscular activity, of casein hydrolyzate, a mixture of amino acids, or phosphoric acid salts, favors the maintenance of a higher than normal level of adenosine triphosphate (ATP) and phosphocreatine (CP) and a corresponding decrease in the level of adenosine diphosphate (ADP) and adenosine monophosphate (AMP) in the muscles.It appears from this study that just as carbohydrate is known to have a protein-sparing action, so amino acids have been found to have a sparing action in the metabolism of carbohydrate and phosphate ester in the animal even under conditions of intense physical exercise at low temperatures.

scholarly journals ADENINE NUCLEOTIDE-INDUCED CONTRACTION OF THE INNER MITOCHONDRIAL MEMBRANE

1973 ◽  
Vol 56 (1) ◽  
pp. 51-64 ◽  
Author(s):  
Clinton D. Stoner ◽  
Howard D. Sirak
Keyword(s):  
Mitochondrial Membrane ◽  
Adenine Nucleotide ◽  
Adenine Nucleotides ◽  
Mitochondrial Protein ◽  
Adenosine Diphosphate ◽  
High Energy ◽  
Maximal Contraction ◽  
High Energy Phosphate ◽  
Inner Mitochondrial Membrane ◽  
Inner Membrane

The inner membranes of isolated bovine heart mitochondria undergo pronounced contraction upon being exposed to exogenous adenosine diphosphate (ADP), adenosine triphosphate (ATP), and certain other high-energy phosphate compounds. Contraction results in decrease of inner membrane expanse which in turn results in decrease of intracristal space and increase of mitochondrial optical density (OD). The magnitude of the OD change appears to be proportional to the degree of contraction Half-maximal contraction can be achieved with ADP or ATP at concentrations as low as about 0 3 µM. Atractyloside at concentrations as low as about 1.2 nmol/mg mitochondrial protein completely inhibits the contraction. It is concluded from these and other observations that inner membrane contraction occurs as a result of adenine nucleotide binding to the carrier involved in the exchange of adenine nucleotides across the inner mitochondrial membrane.

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