Carbofuran-induced alterations (in vivo) in high-energy phosphates, creatine kinase (CK) and CK isoenzymes

1991 ◽  
Vol 65 (4) ◽  
pp. 304-310 ◽  
Author(s):  
Ramesh C. Gupta ◽  
John T. Goad ◽  
Wade L. Kadel
Keyword(s):  
Creatine Kinase ◽  
High Energy ◽  
High Energy Phosphates

Phosphocreatine content of freeze-clamped muscle: influence of creatine kinase inhibition

2003 ◽  
Vol 94 (5) ◽  
pp. 1751-1756 ◽  
Author(s):  
Jeffrey J. Brault ◽  
Kirk A. Abraham ◽  
Ronald L. Terjung
Keyword(s):  
Creatine Kinase ◽  
Kinase Inhibitor ◽  
Fiber Type ◽  
High Energy ◽  
High Energy Phosphates ◽  
Kinase Inhibition ◽  
Chemical Measurements ◽  
Cellular Energetics ◽  
Muscle Energetic

The study of cellular energetics is critically dependent on accurate measurement of high-energy phosphates. Muscle values of phosphocreatine (PCr) vary greatly between in vivo measurements (i.e., by nuclear magnetic resonance) and chemical measurements determined from muscles isolated and quick-frozen. The source of this difference has not been experimentally identified. A likely cause is activation of ATPases and phosphotransfer from PCr to ADP. Therefore, rat hindlimb skeletal muscle was perfused either with or without 2 mM iodoacetamide, a creatine kinase inhibitor, and muscle was freeze-clamped either at rest or after contraction. Creatine kinase inhibition resulted in ∼6 μmol/g higher PCr and lower creatine in the freeze-clamped soleus, red gastrocnemius, and white gastrocnemius. This PCr content difference was reduced when the initial PCr content was decreased with prior contractions. Therefore, the amount of PCr artifact appears to scale with initial PCr content within a fiber-type section. This artifact directly affects the measurement and, thus, the calculations of muscle energetic parameters from studies using isolated and frozen muscle.

Metabolic and energy correlates of intracellular pH in progressive fatigue of squid (L. brevis) mantle muscle

1996 ◽  
Vol 271 (5) ◽  
pp. R1403-R1414 ◽  
Author(s):  
H. O. Portner ◽  
E. Finke ◽  
P. G. Lee
Keyword(s):  
Free Energy ◽  
Critical Velocity ◽  
Energy Levels ◽  
High Energy ◽  
Swimming Velocity ◽  
High Energy Phosphates ◽  
Energy Status ◽  
Intracellular Acidosis ◽  
Model Calculations

Squid (Lolliguncula brevis) were exercised at increasing swimming speeds to allow us to analyze the correlated changes in intracellular metabolic, acid-base, and energy status of the mantle musculature. Beyond a critical swimming velocity of 1.5 mantle lengths/s, an intracellular acidosis developed that was caused by an initial base loss from the cells, the onset of respiratory acidification, and, predominantly, octopine formation. The acidosis was correlated with decreasing levels of phospho-L-arginine and, thus, supported ATP buffering at the expense of the phosphagen. Monohydrogenphosphate, the actual substrate of glycogen phosphorylase accumulated, enabling glycogen degradation, despite progressive acidosis. In addition to octopine, succinate, and glycerophosphate accumulation, the onset of acidosis characterizes the critical velocity and indicates the transition to a non-steady-state time-limited situation. Accordingly, swimming above the critical velocity caused cellular energy levels (in vivo Gibbs free energy change of ATP hydrolysis) to fall. A minimal value was reached at about -45 kJ/mol. Model calculations demonstrate that changes in free Mg2+ levels only minimally affect ATP free energy, but minimum levels are relevant in maintaining functional concentrations of Mg(2+)-complexed adenylates. Model calculations also reveal that phosphagen breakdown enabled L. brevis to reach swimming speeds about three times higher than the critical velocity. Comparison of two offshore squid species (Loligo pealei and Illex illecebrosus) with the estuarine squid L.brevis indicates that the latter uses a strategy to delay the exploitation of high-energy phosphates and protect energy levels at higher than the minimum levels (-42 kJ/mol) characterizing fatigue in the other species. A more economical use of anaerobic resources and an early reduction in performance may enable L. brevis to tolerate more extreme environmental conditions in shallow estuarine waters and even hypoxic environments and to prevent a fatal depletion of energy stores.

Cardiac force and high-energy phosphates under metabolic inhibition in four ectothermic vertebrates

1996 ◽  
Vol 271 (4) ◽  
pp. R946-R954 ◽  
Author(s):  
T. Hartmund ◽  
H. Gesser
Keyword(s):  
Creatine Kinase ◽  
Atpase Activity ◽  
Kinase Activity ◽  
Energy State ◽  
High Energy ◽  
Creatine Kinase Activity ◽  
The Other ◽  
Freshwater Turtle ◽  
High Energy Phosphates ◽  
Isometric Twitch

Isometric twitch tension of ventricular preparations stimulated at 0.2 Hz fell over 30 min of anoxia by a fraction decreasing in the order rainbow trout, cod, eel, and freshwater turtle. Drops in the estimated cytoplasmic energy state were related to larger tension losses for trout than for the other species, possibly due to larger changes in free phosphate. Anoxic energy degradation was slower for turtle than for the other species. Anoxia combined with glycolytic inhibition (1 mmol/l iodoacetate) enhanced the decrease in twitch tension for a drop in energy state and enlarged the increase in ADP/ATP relative to that in creatine/phosphocreatine to an extent inversely related to the creatine kinase activity. Furthermore, it increased resting tension to an extent possibly related to myosin-adenosinetriphosphatase (ATPase) activity and lowered the content of phosphorylated adenylates in trout and turtle myocardium. The results indicate that species differences in performance of the metabolically challenged myocardium depend on energy-degrading processes, e.g., myosin-ATPase activity, phosphate release, creatine kinase activity, and efflux/degradation of ADP and AMP, and that glycolysis offers protection due to its cytoplasmic localization.

scholarly journals Niacin protects the isolated heart from ischemia-reperfusion injury

2000 ◽  
Vol 279 (2) ◽  
pp. H764-H771 ◽  
Author(s):  
Nathan A. Trueblood ◽  
Ravichandran Ramasamy ◽  
Li Feng Wang ◽  
Saul Schaefer
Keyword(s):  
Creatine Kinase ◽  
Redox Regulation ◽  
Ischemia Reperfusion Injury ◽  
Isolated Heart ◽  
Ischemia Reperfusion ◽  
High Energy ◽  
Low Flow ◽  
High Energy Phosphates ◽  
Zero Flow ◽  
Pyruvate Ratio

Nicotinic acid (niacin) has been shown to decrease myocyte injury. Because interventions that lower the cytosolic NADH/NAD+ratio improve glycolysis and limit infarct size, we hypothesized that 1) niacin, as a precursor of NAD+, would lower the NADH/NAD+ratio, increase glycolysis, and limit ischemic injury and 2) these cardioprotective benefits of niacin would be limited in conditions that block lactate removal. Isolated rat hearts were perfused without (Ctl) or with 1 μM niacin (Nia) and subjected to 30 min of low-flow ischemia (10% of baseline flow, LF) and reperfusion. To examine the effects of limiting lactate efflux, experiments were performed with 1) Ctl and Nia groups subjected to zero-flow ischemia and 2) the Nia group treated with the lactate-H+cotransport inhibitor α-cyano-4-hydroxycinnamate under LF conditions. Measured variables included ATP, pH, cardiac function, tissue lactate-to-pyruvate ratio (reflecting NADH/NAD+), lactate efflux rate, and creatine kinase release. The lactate-to-pyruvate ratio was reduced by more than twofold in Nia-LF hearts during baseline and ischemic conditions ( P < 0.001 and P< 0.01, respectively), with concurrent lower creatine kinase release than Ctl hearts ( P < 0.05). Nia-LF hearts had significantly greater lactate release during ischemia ( P < 0.05 vs. Ctl hearts) as well as higher functional recovery and a relative preservation of high-energy phosphates. Inhibiting lactate efflux with α-cyano-4-hydroxycinnamate and blocking lactate washout with zero flow negated some of the beneficial effects of niacin. During LF, niacin lowered the cytosolic redox state and increased lactate efflux, consistent with redox regulation of glycolysis. Niacin significantly improved functional and metabolic parameters under these conditions, providing additional rationale for use of niacin as a therapeutic agent in patients with ischemic heart disease.

Contractile and metabolic effects of increased creatine kinase activity in mouse skeletal muscle

1996 ◽  
Vol 270 (4) ◽  
pp. C1236-C1245 ◽  
Author(s):  
B. B. Roman ◽  
J. M. Foley ◽  
R. A. Meyer ◽  
A. P. Koretsky
Keyword(s):  
Skeletal Muscle ◽  
Creatine Kinase ◽  
Kinase Activity ◽  
Contractile Function ◽  
Contractile Activity ◽  
High Energy ◽  
Metabolic Effects ◽  
High Energy Phosphates ◽  
Lactate Dehydrogenase Activity ◽  
B Subunit

The effects of increased expression of creatine kinase (CK) in skeletal muscle were studied in control and transgenic animals homozygous for expression of the B subunit of CK. CK activity was 47% higher in transgenic gastrocnemius muscle. The CK activity was distributed as follows: 45 +/- 1% MM dinner, 31 +/- 4% MB dimer, and 22 +/- 5% BB dimer. No significant differences in metabolic or contractile proteins were detected except for a 22% decrease in lactate dehydrogenase activity and a 9% decrease in adenylate kinase activity. The only significant effect in contractile activity was that the rise time of a 5-s isometric contraction was 28% faster in the transgenic muscle. 31P nuclear magnetic resonance (NMR) spectra were obtained from control and transgenic muscles during mechanical activation, and there were no NMR measurable differences detected. These results indicate that a 50% increase in CK activity due to expression of the B subunit does not have large effects on skeletal muscle metabolism or contractile function. Therefore, control muscle has sufficient CK activity to keep up with changes in cellular high-energy phosphates except during the early phase of intense contractile activity.

The effect of an adenosine and lidocaine intravenous infusion on myocardial high-energy phosphates and pH during regional ischemia in the rat model in vivo

2006 ◽  
Vol 84 (8-9) ◽  
pp. 903-912 ◽  
Author(s):  
Sarah J. Canyon ◽  
Geoffrey P. Dobson
Keyword(s):  
Body Mass ◽  
Rat Model ◽  
Intravenous Infusion ◽  
High Energy ◽  
Coronary Artery Ligation ◽  
Ischemia And Reperfusion ◽  
High Energy Phosphates ◽  
Regional Ischemia ◽  
Significant Difference

We have previously shown that an intravenous infusion of adenosine and lidocaine (AL) solution protects against death and severe arrhythmias and reduces infarct size in the in vivo rat model of regional ischemia. The aim of this study was to examine the relative changes of myocardial high-energy phosphates (ATP and PCr) and pH in the left ventricle during ischemia–reperfusion using 31P NMR in AL-treated rats (n = 7) and controls (n = 6). The AL solution (A: 305 μg·(kg body mass)–1·min–1; L: 608 μg·(kg body mass)–1·min–1) was administered intravenously 5 min before and during 30 min coronary artery ligation. Two controls died from ventricular fibrillation; no deaths were recorded in AL-treated rats. In controls that survived, ATP fell to 73% ± 29% of baseline by 30 min ischemia and decreased further to 68% ± 28% during reperfusion followed by a sharp recovery at the end of the reperfusion period. AL-treated rats maintained relatively constant ATP throughout ischemia and reperfusion ranging from 95% ± 6% to 121% ± 10% of baseline. Owing to increased variability in controls, these results were not found to be significant. In contrast, control [PCr] was significantly reduced in controls compared with AL-treated rats during ischemia at 10 min (68% ± 7% vs. 99% ± 6%), at 15 min (68% ± 10% vs. 93% ± 2%), and at 20 min (67% ± 15% vs. 103% ± 5%) and during reperfusion at 10 min (56% ± 22% vs. 99% ± 7%), at 15 min (60% ± 10% vs. 98% ± 7%), and at 35 min (63% ± 14% vs. 120% ± 11%) (p < 0.05). Interestingly, changes in intramyocardial pH between each group were not significantly different during ischemia and fell by about 1 pH unit to 6.6. During reperfusion, pH in AL-treated rats recovered to baseline in 5 min but not in controls, which recovered to only around pH 7.1. There was no significant difference in the heart rate, mean arterial pressure, and rate-pressure product between the controls and AL treatment during ischemia and reperfusion. We conclude that AL cardioprotection appears to be associated with the preservation of myocardial high-energy phosphates, downregulation of the heart at the expense of a high acid-load during ischemia, and with a rapid recovery of myocardial pH during reperfusion.

Fish muscle energy metabolism measured during hypoxia and recovery: an in vivo 31P-NMR study

1995 ◽  
Vol 268 (5) ◽  
pp. R1178-R1187 ◽  
Author(s):  
V. van Ginneken ◽  
G. van den Thillart ◽  
A. Addink ◽  
C. Erkelens
Keyword(s):  
Creatine Kinase ◽  
Fish Muscle ◽  
High Energy ◽  
Anaerobic Glycolysis ◽  
O2 Consumption ◽  
Nmr Study ◽  
Creatine Kinase Equilibrium ◽  
Creatine Kinase Reaction ◽  
Muscle Energy Metabolism

Three fish species were exposed to graded hypoxia levels and allowed to recover. Levels of high-energy phosphate compounds in epaxial white muscle were monitored by in vivo 31P nuclear magnetic resonance (NMR) spectroscopy. Furthermore, O2 consumption of the animals was measured. With increasing hypoxia load, metabolic parameters started to change in the following order: phosphocreatine (PCr)-to-Pi ratio (decrease), O2 consumption (decrease), [PCr] (decrease), intracellular pH (pHi; decrease), Pi (increase), free ADP concentration ([ADP]free; increase), [ATP] (decrease). PCr levels fell with the PO2. After each increment, the [PCr] reached a stable plateau value while, in some cases, a recovery was observed. This recovery could be explained because the balance between anaerobic and aerobic metabolism is continuously fluctuating during hypoxia as a consequence of changes in the activity of the fish. Consequently the [ADP]free are fluctuating, resulting in an activation of the creatine kinase reaction and the anaerobic glycolysis. In all three species, anaerobic glycolysis was activated, but in contrast to anoxia exposure, metabolic suppression was absent. The changes of [ADP]free and [H+] (which influences the position of the creatine kinase equilibrium) are species dependent. Species differences observed in the other parameters were small. It is concluded that the pattern of the activation of anaerobic metabolism under deep hypoxia is different from that under anoxia.

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