Energy Charge Levels Research Articles

Reductant and energy level of bacteroids of Rhizobium leguminosarum

Low redox potential electron carriers such as benzyl viologen and NAD + were reduced by bacteroids prepared from nodules of pea inoculated with hup + R. leguminosarum strain Vp1, whereas, the bacteroids of plasmid cured hup − derivative Vm1 did not exhibit the reducing activity. The bacteroids prepared from nodules of hup + strain Vp1 at 46d stage, where nitrogenase activity was maximum, exhibited 1.5-fold higher levels of NADH/NADPH, two-fold higher levels of ATP while the level of ADP and AMP were lower as compared to the bacteroids of hup − strain Vm1. Also the level of adenylate energy charge in hup + bacteroids was 29% higher than the hup − bacteroids.

111 QUALITATIVE AND QUANTITATIVE STUDIES ON THE NUCLEOTIDES OF INTESTINAL MUCOSA

The conversion of hypoxanthine and xanthine to urate via xanthine oxidase (Xanthine: oxygen oxidoreductase (E.C. 1.1.3.22.) may when ischaemic tissues are re-oxygenated generates radical oxygen species. Such ischaemia may be involved in the adverse effects of non-steroidal anti-inflammatory drugs (NSAIDS) on the human intestine where high levels of xanthine oxidase are known to be present. However little qualitative or quantitative information concerning the nucleotide content of intestine is available. We have determined the nucleotide profiles in freeze-clamped sections of rat intestine (stomach, jejunum, ileum and colon) and for comparison liver and heart by anion-exchange HPLC and quantified the individual nucleotides. The mean of 10 analyses are summarised below The results suggests that the intestine is a major site of nucleotide metabolism with nucleotide concentrations equivalent to liver rather than heart. A slight concentration gradient down the gut was observed. During short-term absorption studies using saline, glucose, acetate and citrate neither energy charge nor absolute levels of nucleotides changed significantly. Rapid degradation of nucleotides was induced by warm ischaemia and NSAID's.

Adenine nucleotide content and energy charge of Azotobacter vinelandii during batch growth in dialysed-soil medium

The levels of intracellular adenine nucleotides, energy charge and oxygen consumption, have been investigated in vegetative cells of Azotobacter vinelandii grown in chemically-defined medium and dialysed-soil medium. Microorganisms cultured in dialysed-soil medium displayed lower oxygen consumption activities and energy charge values than those cultured in chemically-defined medium. Also, the ATP/ADP ratio was much higher in vegetative cells grown in chemically-defined medium, and the intracellular levels of ATP were lower in cells cultured in dialysed-soil medium.

Changes in concentrations of respiratory components and cytochrome oxidase activity in mitochondria obtained from carbon tetrachloride-induced cirrhotic rat liver.

1. Changes in the concentrations of respiratory components, phosphorylative activity, the cytochrome oxidase activity of mitochondria and the hepatic adenylate energy charge level (in situ) were studied in cirrhotic rat liver induced by carbon tetrachloride (CCl4). 2. In the cirrhotic liver mitochondria, concentrations of cytochrome a(+a3), cytochrome b, coenzyme Q9 and coenzyme Q10 increased significantly to 2.44 +/- 0.02 x 10(-10) (mean +/- SE), 1.37 +/- 0.05 x 10(-10), 25.57 +/- 0.47 x 10(-10) and 5.39 +/- 0.26 x 10(-10) mol/mg of mitochondrial protein, respectively, compared with 1.83 +/- 0.03 x 10(-10), 1.22 +/- 0.02 x 10(-10), 16.24 +/- 0.39 x 10(-10) and 1.81 +/- 0.07 x 10(-10) in normal rats [P less than 0.001 for cytochrome a(+a3), coenzyme Q9 and coenzyme Q10, and P less than 0.01 for cytochrome b]. 3. Concentrations of flavoprotein and pyridine nucleotides decreased significantly to 13.33 +/- 0.14 x 10(-10) and 45.68 +/- 1.59 x 10(-10) mol/mg of mitochondrial protein, respectively, compared with 14.79 +/- 0.33 x 10(-10) and 86.26 +/- 1.83 x 10(-10) in normal rats (P less than 0.001). There was no significant difference in the concentration of cytochrome c(+c1). 4. Cytochrome oxidase activity per unit of cytochrome a(+a3) increased significantly to 67.43 +/- 1.71 atoms O s-1 mol-1, compared with 55.77 +/- 1.16 in normal rats (P less than 0.001). By contrast, phosphorylative activity per unit of cytochrome a(+a3) decreased significantly in the cirrhotic liver to 10.40 +/- 0.36 s-1 compared with 13.43 +/- 0.49 in normal rats (P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of partial ischemia and reflow on mitochondrial metabolism in rat liver.

To clarify the effects of partial ischemia and reflow on the mitochondrial metabolism of the rat liver, the afferent vessels supplying the left lateral and left half of medial lobes were occluded and then reperfused after given time periods of ischemia (30, 60, 90 and 120 min, groups A, B, C and D, respectively). Samplings were taken at 0, 10 and 60 min after reperfusion. The energy charge levels of ischemic lobes decreased rapidly from 0.85 +/- 0.01 in the sham group to 0.38 +/- 0.11, 0.35 +/- 0.07 and 0.34 +/- 0.06 in groups B, C and D, respectively. The phosphorylative activities of mitochondria isolated from ischemic lobes decreased gradually along with the time of ischemia. The reversal of mitochondrial function and energy charge levels following reperfusion was noted in groups A and B. In nonischemic lobes, the phosphorylation rate (nmol ATP/mg/min) increased from 90 +/- 6 in sham group to 125 +/- 12 and 130 +/- 9; 131 +/- 5 and 130 +/- 6; 123 +/- 6 and 122 +/- 17, and 138 +/- 6 and 138 +/- 13 at 10 and 60 min after reflow in groups A, B, C and D, respectively (p less than 0.05). The energy charge level of nonischemic lobes decreased from 0.85 +/- 0.01 of sham group to 0.80 +/- 0.03 in group D (p less than 0.05). From these results, it is concluded that the transitional zone for the reversal of mitochondria function and energy metabolism following prolonged liver ischemia appears at around 60 min.(ABSTRACT TRUNCATED AT 250 WORDS)

Changes in energy metabolism of allografts after liver transplantation.

To evaluate the function of energy metabolism in allografts after liver transplantation, changes in hepatic energy charge levels, oxidative and phosphorylative activities of mitochondria and arterial blood ketone body ratio (acetoacetate/3-hydroxybutyrate; KBR) were studied in piglets. Hepatic energy charge levels decreased to 0.831 +/- 0.010 at 3 days and 0.836 +/- 0.009 at 3 weeks after operation compared to the preoperative value of 0.868 +/- 0.006 (p less than 0.01), and returned to 0.856 +/- 0.007 at 6 weeks. Mitochondrial oxidative and phosphorylative activities were moderately enhanced to 19.14 +/- 2.07 (10(-10) mol ATP/mg of mitochondrial protein/s) at 3 days and 20.89 +/- 1.72 at 3 weeks compared to the preoperative value of 16.74 +/- 2.36, and returned to 16.65 +/- 1.54 at 6 weeks. There was no significant difference in the concentrations of mitochondrial respiratory components, except in cytochrome c + c1. KBR decreased immediately at the beginning of the anhepatic phase and rapidly recovered to the preoperative level within 60 min after revascularization of allografts. There was no change in KBR during the postoperative course except in cases with clinical deterioration. From these results, it is suggested that the mitochondrial capacity for ATP synthesis was enhanced to compensate for the decreased energy charge level and that a decreased KBR is a sign of a critically deranged metabolic function in allografts.

Adenine nucleotide content and energy charge in dry cells of [formula omitted][formula omitted] grown in dialysed soil medium

The levels of intracellular adenine nucleotide, energy charge and oxygen consumption, have been investigated in dry vegetative cells of Azotobacter vinelandii grown in a chemically-defined medium and a dialysed-soil medium. The data show that under desiccation conditions the cells cultured in dialysed-soil medium retain viability at energy charge values of 0.29 and ATP/ADP ratio 0.22, whereas under the same desiccation condition, vegetative cells grown in chemically-defined medium die at energy charge values < 0.5 and ATP/ADP ratio < 0.54.

Protective action of 1,3-butanediol in cerebral ischemia. A neurologic, histologic, and metabolic study.

1,3-Butanediol (BD) is converted in the body to beta-hydroxybutyrate, and previous studies have shown that hyperketonemia had beneficial effects in experimental models of generalized hypoxia. The aim of this study was to determine if BD would reduce brain damage following cerebral ischemia. A transient forebrain ischemia of 30-min duration was induced by the four-vessel occlusion technique in control and BD-treated rats (25 mmol/kg, i.p.; 30 min prior to ischemia). BD treatment led to significant improvement of neurologic deficit during the 72-h recovery period and reduced neuronal damage in the striatum and cortex but not in the CA1 sector of the hippocampus. Evaluation of cerebral energy metabolism before and at the end of the ischemic period showed that the treatment did not change the preischemic glycolytic and energy metabolite levels but attenuated the ischemia-induced metabolic alterations. It increased energy charge, phosphocreatine, and glucose levels, and reduced lactate accumulation. The decrease in brain lactate concentration might account for the beneficial effects of BD by minimizing the neuropathological consequences of lactic acidosis.

The Influence of Hemodilution in Normal and Cirrhotic Rats in Relation to Hepatic Energy Metabolism

The effects of acute hemodilution on hepatic energy status were compared between carbon-tetrachloride-induced cirrhotic rats and normal rats, using arterial blood ketone body ratio and hepatic energy charge as indices. Arterial blood was withdrawn and replaced with rat plasma in hemodiluted rats and with whole blood in sham-diluted control rats. In normal rats, arterial blood ketone body ratio and energy charge level at 6 hours after hemodilution decreased when the hematocrit value was less than 15%. In contrast, the values decreased at an even higher hematocrit level in cirrhotic rats. It was suggested from these results that the hemodilution procedure exerts a more profound hypoxic effect at a milder hemodilution on a cirrhotic liver than on a normal liver.

The Influence of Hemodilution in Normal and Hepatectomized Rats in Relation to Hepatic Energy Metabolism

The effects and safety limits of acute hemodilution on hepatic energy status were determined by comparison of arterial blood ketone body ratio (acetoacetate/3-hydroxybutyrate) and hepatic energy charge levels in 70% hepatectomized rats and nonhepatectomized rats. Arterial blood was withdrawn and replaced with rat plasma in hemodiluted rats and with whole blood in sham-diluted control rats. The arterial blood ketone body ratio at 6 hours after hemodilution in hepatectomized and sham-diluted rats (0.454±0.037) was lower than that of nonhepatectomized and sham-diluted rats (0.686±0.044). In hepatectomized groups, it decreased to 0.403±0.043 when the hematocrit value was less than 20% and to 0.286±0.031 when it was less than 15%. In hepatectomized rats, hepatic energy charge at 6 hours after hemodilution was 0.809±0.021 in sham-diluted controls, but decreased to less than 0.8 when the hematocrit was less than 20%. On the other hand, in nonhepatectomized rats, the energy charge was greater than 0.8 even when the hematocrit was less than 15%. These results suggest that hemodilution procedure exerts more profound hypoxic effect on the remnant liver than on the normal one.

Influence of hemodilution on hepatic energy metabolism in rat.

The effects and safety limits of acute hemodilution on hepatic energy status were investigated in relation to arterial blood ketone body ratio and hepatic energy charge in a hemodilution rat model. As long as the hematocrit value was maintained above 20%, ketone body ratio and energy charge level at 6 h after hemodilution remained at the same levels as those of the sham-diluted groups. However, when hematocrit value was less than 15%, the ketone body ratio markedly decreased from the control value of 0.686 +/- 0.044 to 0.278 +/- 0.048 (p less than 0.001), and energy charge decreased from the control value of 0.856 +/- 0.012 to 0.0806 +/- 0.011 (p less than 0.01). From these results, it was suggested that hemodilution exerts no influence on the energy status of the liver as long as hematocrit is maintained above 20%.

Changes in Adenine Nucleotides and Energy Charge in Isolated Winter Wheat Cells During Low Temperature Stress

Adenylate energy charge (AEC) and adenine nucleotide levels of isolated winter wheat (Triticum aestivum L. cv Kharkov 22 MC) cells exposed to various low temperature stresses were determined. During ice encasement at -1 degrees C, nucleotide levels decreased gradually in approximate relation to a decline in cell viability. AEC values remained high even after 5 weeks of icing when cell viability was severely reduced. When isolated cell suspensions were exposed to various cooling and freezing regimes ranging from -10 to -30 degrees C, cell damage was dependent on the minimum temperature imposed and the duration of exposure to the freezing stress. The levels of all three adenine nucleotides declined with increasing severity of the imposed stress, but AEC values remained high even at -30 degrees C when nearly all of the cells were killed. The addition of 10 millimolar Ca(2+) to cell suspensions enhanced survival during low temperature stresses, but did not influence nucleotide levels other than through its effect on cell viability. These results indicate that impairment of the ion transport system during the early stages of ice encasement prior to a detectable decline in cell viability cannot be attributed to changes in the adenylate energy charge system of the cell.

Effect of hepatic artery embolization on the adenylate energy charge level and the redox state of the cirrhotic liver.

Hepatic energy charge ((ATP + 1/2ADP)/(ATP + ADP + AMP)) and arterial blood ketone body ratio (acetoacetate/3-hydroxybutyrate) were measured after hepatic artery embolization in carbon-tetrachloride-induced cirrhotic rats. In normal livers, energy charge slightly decreased at 3 h and returned to normal levels at 6 h. By contrast, in cirrhotic livers, energy charge was drastically decreased at 3 h after embolization and was not completely recovered at 6 h. Blood ketone body ratio, reflecting hepatic mitochondrial redox (NAD+/NADH) state, also decreased at 3 h after embolization in both groups, and its recovery was not observed in cirrhotic group at 6 h.

Malnutrition at the cellular level in uremia: a new frontier for research.

Previously reported studies showed that protein-calorie malnutrition (PCM) in children is associated with significant alterations in muscle cell composition, characterized by increased cell water and Na, with decreased concentrations of K, Mg, and some glycolytic and citric acid cycle metabolites. In PCM, the i.c. H2O and levels of Na and K were significantly related, by multiple regression analysis, to the combined set of simultaneously measured levels of cell metabolites, phosphoenolpyruvate, pyruvate, alpha-ketoglutarate, and oxaloacetate. Cell bioactivities also were affected by PCM. Activities of the enzymes pyruvate kinase and malic and isocitric dehydrogenases were significantly reduced in muscle homogenates of PCM children. Kinetic analysis of pyruvate kinase indicated an 8-10-fold reduction in maximal velocity of the enzyme, consistent with a reduction in enzyme protein. Additionally, reduced levels of ATP and the equilibrium constant of the adenylate kinase system were observed in leukocytes of PCM children. Alterations in the activity of the energy-dependent Na pump have been noted by others in association with the accumulation of i.c. Na in severe malnutrition. Neither protein synthesis nor amino acid pools was measured in these previously reported studies. Recent data from several laboratories show that the "profiles" of i.c. and plasma amino acids are very different, both in uremics and in control subjects. In control subjects, with leukocytes as the cell model, the level of protein synthesis can be predicted by multiple regression analyses from simultaneously measured levels of plasma or i.c. amino acids. Intracellular amino acids are better predictors. Of 19 intracellular amino acids, a combination of five accounted for 54% of the variance in protein synthesis in normal, healthy adults. Levels of these predictor cell amino acids can, in turn, be predicted by different combinations of apparently unrelated plasma amino acids. In adult uremic patients stabilized by hemodialysis, with leukocytes as the cell model, levels of ATP, energy charge, adenylate kinase and pyruvic kinase activities were reduced. Others have reported increased i.c. water and Na contents, and impaired Na pump activity. Cell levels of methionine and the branched-chain amino acids, valine, leucine, and isoleucine, and protein synthesis also were significantly reduced. By multiple regression analysis, the observed levels of protein synthesis and energy charge in the hemodialyzed uremic patients were largely accounted for by different combinations of intracellular amino acid than in healthy subjects.(ABSTRACT TRUNCATED AT 400 WORDS)

Sequential changes in blood concentrations of fuels in relation to arterial blood ketone body ratio after 70% hepatectomy in rabbits.

The changes in arterial blood levels of glucose, free fatty acids, ketone bodies, and amino acids were investigated after 70% hepatectomy in rabbits in relation to the changes in adenylate energy charge of the remnant liver and ketone body ratio of arterial blood. Hepatic energy charge decreased to 0.767 +/- 0.008 within 24 h (p less than 0.001), and arterial blood ketone body ratio decreased to 0.415 +/- 0.041 within 12 h (p less than 0.001). Plasma free fatty acid concentrations increased to about twice the original values within 12 h (p less than 0.01), total amino acid concentrations also doubled within 24 h (p less than 0.01), and blood glucose levels decreased to below 100 mg/dl at 12 and 24 h (p less than 0.05). Afterward, at 96 h postoperatively (p.o.), blood ketone body ratio and energy charge levels were restored to near normal levels with the normalization of blood glucose, plasma free fatty acids, and plasma amino acids. These findings suggest that the decreased energy charge of the remnant liver concomitant with a fall in blood ketone body ratio may be the basis of the sequential changes in the blood concentration of fuels after massive hepatectomy.

Effect of Exogenous Nitrate on Anaerobic Metabolism in Excised Rice Roots

Reggiani, R., Brambilla, I. and Bertani, A. 1985. Effect of exogenous nitrate on anaerobic metabolism in excised rice roots. II Fermentative activity and adenylic energy charge.—J. exp. Bot 36: 1698–1704. The presence of nitrate in the culture medium of excised sterile rice roots stimulated CO2 and ethanol evolution and, to a smaller extent, alanine accumulation. The increased anaerobic carbohydrate consumption observed in roots grown on nitrate is consistent with the constantly higher level of adenylic energy charge. An hypothesis serving to explain the evidence concerning the effect of nitrate on anaerobically grown rice roots is proposed.

Effects of multi-dose methylprednisolone sodium succinate administration on injured cat spinal cord neurofilament degradation and energy metabolism.

Thirty minutes after experimental spinal cord contusion (500 gm-cm) injury, cats were treated with an initial intravenous dose of either vehicle (V) or 30 mg/kg of Solu-Medrol sterile powder (methylprednisolone sodium succinate; MPSS). Two hours later, cats received a second intravenous injection of either V or 15 mg/kg MPSS, giving three treatment groups: V/V; MPSS/V; MPSS/MPSS. At 4 1/2 hours following injury of the cat lumbar spinal cord, the gray and white matter neurofilament protein content was reduced by over 70% within the injured segment of V/V-treated animals. The three major cat spinal cord neurofilament protein subunits of 200,000, 152,000, and 76,000 daltons were reduced in parallel by the injury. Treatment of cats with a single 30-mg/kg dose of MPSS (MPSS/V) provided a clear, although not significant, protection against neurofilament degradation compared with V/V-treated cats when measured at 4 1/2 hours after injury. The lactic acid content of the injured spinal cord segment at 4 1/2 hours after injury was significantly elevated in both V/V- and MPSS/V-treated cats, while the adenosine triphosphate (ATP) content, total adenylates, and energy charge were significantly reduced. The administration of a second intravenous 15-mg/kg dose of MPSS 2 hours after the initial 30-mg/kg dose (MPSS/MPSS) provided complete (p less than 0.01) preservation of neurofilaments within the injured spinal cord segment measured at 4 1/2 hours after injury. The levels of lactate, ATP, total adenylates, and tissue energy charge in MPSS/MPSS-treated cats were not different from those of uninjured spinal cords following laminectomy. The (Na+ + K+)-ATPase activity in the injured spinal segment was enhanced, although highly variable, in MPSS/V-treated animals. On the other hand, spinal cord enzyme activity was significantly and consistently elevated in the MPSS/MPSS-treated group. The results demonstrate that a 30-mg/kg dose of MPSS followed at 2 hours by a 15-mg/kg dose provides significantly better protection against injury-induced ischemia and Ca++-dependent neurofilament degradation than a single 30-mg/kg dose. These findings are in agreement with the spinal cord tissue pharmacokinetics and time-action characteristics of methylprednisolone observed in earlier studies.

Significance of mitochondrial enhancement in hepatic energy metabolism in relation to alterations in hemodynamics in septic pigs with severe peritonitis.

Liver mitochondrial phosphorylative activity, hepatic adenine nucleotides, and hemodynamic parameters were studied in 23 pigs with peritonitis induced by cecal ligation and perforation. Between 2 and 7 days after treatment, the onset of an apparent hyperdynamic state, characterized by an increased cardiac index and decreased total peripheral resistance index, occurred. In this period, the energy charge level was barely maintained and the occurrence of liver mitochondrial enhancement was observed. However, 10-14 days after treatment, the onset of a hypodynamic state with its inverse patterns in hemodynamics took place. In this period, the energy charge level fell to 0.68, concomitant with a marked decrease in mitochondrial function. Further, a high positive correlation between the cardiac index and liver mitochondrial phosphorylative activity was noted (r = 0.85, p less than 0.01). These results suggest that liver mitochondria play a major role in the metabolic and hemodynamic adaptations occurring during sepsis.

Changes in blood glucose levels in relation to blood ketone body ratio following hypertonic glucose infusion in 70% hepatectomized rabbits.

The effects of postoperative infusion of a hypertonic glucose solution on the blood glucose level, blood ketone body ratio (acetoacetate/beta-hydroxybutyrate), and plasma alanine and proline levels were studied in 70% hepatectomized rabbits (group A) and in rabbits 70% hepatectomized and, in addition, subjected to bile duct obstruction at 12 h after hepatectomy (group B). Glucose infusion was started at the end of hepatectomy and continued for 20 h. The blood glucose level in group A remained at approximately 300 mg/dl throughout the study; however, it reached 789 mg/dl in group B at 20 h. The blood ketone body ratio, which reflects hepatic mitochondrial redox potential, decreased from 0.90 +/- 0.09 in untreated rabbits to 0.38 +/- 0.05 in group A, and to 0.19 +/- 0.03 in group B at 20 h. As the blood ketone body ratio decreased, plasma proline and alanine levels increased rapidly (proline, r = -0.601, p less than 0.02; alanine, r = -0.640, p less than 0.001). In addition, the blood ketone body ratio was positively correlated with the hepatic energy charge level [(ATP + 0.5 ADP)/(ATP + ADP + AMP)] (r = 0.57, p less than 0.001). It is suggested that the entry of glucose and amino acids into the Krebs cycle is inhibited as the blood ketone body ratio decreases, and under such conditions the infused glucose tends to accumulate, resulting in severe hyperglycemia.

Adenosine triphosphate and adenylate energy charge in relation to dormancy of wild oat seeds

Adenosine phosphates, expressed as ATP and energy charge levels, were compared in genetically identical dormant and nondormant caryopses of wild oat (Avena fatua L.). Air-dry nondormant caryopses had a larger pool of ATP and a higher energy charge than dormant caryopses. During the early hours of imbibition of water by dormant caryopses, ATP levels and energy charge increased indicating they are not limiting factors for germination. Moreover, during the induction of germination in dormant caryopses by gibberellic acid (GA3), changes in energy charge were similar to those observed on water, indicating that GA3 does not overcome dormancy simply by elevating energy charge levels. In a second study, ATP and energy charge were measured in initially dormant caryopses incubated under conditions of temperature that either removed or retained dormancy. Both embryo and endosperm extracts demonstrated correlations between levels of ATP or energy charge with temperature of incubation but not with the state of dormancy. The conclusions drawn from both lines of investigation do not support the hypothesis that release of dormancy is related to the metabolism of adenosine phosphates in caryopses of wild oat.