scholarly journals Intracellular Phosphate and ATP Depletion Measured by Magnetic Resonance Spectroscopy in Patients Receiving Maintenance Hemodialysis

2020 ◽  
Vol 32 (1) ◽  
pp. 229-237
Author(s):  
Guillaume Chazot ◽  
Sandrine Lemoine ◽  
Gabriel Kocevar ◽  
Emilie Kalbacher ◽  
Dominique Sappey-Marinier ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
High Energy ◽  
Atp Depletion ◽  
Resonance Spectroscopy ◽  
High Energy Phosphates ◽  
Phosphorus Magnetic Resonance Spectroscopy ◽  
Intracellular Compartment ◽  
Hemodialysis Treatment ◽  
Intracellular Phosphate

BackgroundThe precise origin of phosphate that is removed during hemodialysis remains unclear; only a minority comes from the extracellular space. One possibility is that the remaining phosphate originates from the intracellular compartment, but there have been no available data from direct assessment of intracellular phosphate in patients undergoing hemodialysis.MethodsWe used phosphorus magnetic resonance spectroscopy to quantify intracellular inorganic phosphate (Pi), phosphocreatine (PCr), and βATP. In our pilot, single-center, prospective study, 11 patients with ESKD underwent phosphorus (31P) magnetic resonance spectroscopy examination during a 4-hour hemodialysis treatment. Spectra were acquired every 152 seconds during the hemodialysis session. The primary outcome was a change in the PCr-Pi ratio during the session.ResultsDuring the first hour of hemodialysis, mean phosphatemia decreased significantly (−41%; P<0.001); thereafter, it decreased more slowly until the end of the session. We found a significant increase in the PCr-Pi ratio (+23%; P=0.001) during dialysis, indicating a reduction in intracellular Pi concentration. The PCr-βATP ratio increased significantly (+31%; P=0.001) over a similar time period, indicating a reduction in βATP. The change of the PCr-βATP ratio was significantly correlated to the change of depurated Pi.ConclusionsPhosphorus magnetic resonance spectroscopy examination of patients with ESKD during hemodialysis treatment confirmed that depurated Pi originates from the intracellular compartment. This finding raises the possibility that excessive dialytic depuration of phosphate might adversely affect the intracellular availability of high-energy phosphates and ultimately, cellular metabolism. Further studies are needed to investigate the relationship between objective and subjective effects of hemodialysis and decreases of intracellular Pi and βATP content.Clinical Trial registry name and registration number Intracellular Phosphate Concentration Evolution During Hemodialysis by MR Spectroscopy (CIPHEMO), NCT03119818

Magnetic resonance spectroscopy of high-energy phosphates and lactate immediately after coronary artery bypass surgery

Perfusion ◽  
1998 ◽  
Vol 13 (5) ◽  
pp. 328-333 ◽  
Author(s):  
D NF Harris ◽  
J A Wilson ◽  
S D Taylor-Robinson ◽  
K M Taylor
Keyword(s):  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Cerebral Ischaemia ◽  
Artery Bypass ◽  
High Energy ◽  
Jugular Bulb ◽  
Resonance Spectroscopy ◽  
High Energy Phosphates ◽  
Intracellular Acidosis ◽  
High Incidence

Hypothermic cardiopulmonary bypass (CPB) is associated with a high incidence of neuropsychological defects, marked cerebral swelling immediately after surgery and jugular bulb desaturation during rewarming. This suggests cerebral ischaemia may occur, but evidence is indirect. We studied four patients with 31P magnetic resonance spectroscopy (MRS) and four with 1H MRS before and immediately after coronary surgery. There was no visible lactate in 1H MR spectra. In 31P MR spectra, the ratio of phosphocreatine to adenosine triphosphate was maintained (before: 2.13 ± 0.86 vs after: 2.57 ± 1.31; mean ± 1 SD) and there was no intracellular acidosis (intracellular pH: 7.1 ± 0.04 vs 7.16 ± 0.08), while phosphocreatine/inorganic phosphate was increased immediately after the operation (2.92 ± 0.37 vs 6.39 ± 2.67, p = 0.03). This suggests rebound replacement of energy stores following recovery from temporary cerebral ischaemia during CPB: intra-operative studies would be needed to test this hypothesis further.

scholarly journals Acute Cerebral Ischaemia: Concurrent Changes in Cerebral Blood Flow, Energy Metabolites, pH, and Lactate Measured with Hydrogen Clearance and 31P and 1H Nuclear Magnetic Resonance Spectroscopy. III. Changes following Ischaemia

1988 ◽  
Vol 8 (6) ◽  
pp. 816-821 ◽  
Author(s):  
Kathryn Allen ◽  
Albert L. Busza ◽  
H. Alan Crockard ◽  
Richard S. J. Frackowiak ◽  
David G. Gadian ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Nuclear Magnetic Resonance Spectroscopy ◽  
High Energy ◽  
Resonance Spectroscopy ◽  
High Energy Phosphates ◽  
Bilateral Carotid ◽  
Hydrogen Clearance ◽  
Nuclear Magnetic

CBF has been measured with the hydrogen clearance technique in the two cerebral hemispheres of the gerbil under halothane anaesthesia. At the same time, intracellular pH and the concentrations of lactate and high-energy phosphates were measured in the brain using 1H and 31P nuclear magnetic resonance spectroscopy. Flow and metabolism have been followed during either a 15- or a 30-min ischaemic period (induced by bilateral carotid occlusion) and for up to 1 h of recovery. There was no significant difference between the flow characteristics of the two experimental groups. High-energy phosphate levels and pH returned to control within ∼20 min of the end of the ischaemic period. Lactate clearance, following a 30-min occlusion, was slower than the recovery of pH. The concentration of free ADP, calculated from the creatine kinase equilibrium, was lower during the recovery phase than under control conditions.

scholarly journals Observation of intramyocellular lipids by means of 1H magnetic resonance spectroscopy

1999 ◽  
Vol 58 (4) ◽  
pp. 841-850 ◽  
Author(s):  
Chris Boesch ◽  
Jacques Décombaz ◽  
Johannes Slotboom ◽  
Roland Kreis
Keyword(s):  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
High Energy ◽  
Muscle Physiology ◽  
High Temporal Resolution ◽  
Resonance Spectroscopy ◽  
High Energy Phosphates ◽  
Intramyocellular Lipids ◽  
Before And After ◽  
Recovery Protocols

Magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) are being increasingly used for investigations of human muscle physiology. While MRI reveals the morphology of muscles in great detail (e.g. for the determination of muscle volumes), MRS provides information on the chemical composition of the tissue. Depending on the observed nucleus, MRS allows the monitoring of high-energy phosphates (31P MRS), glycogen (13C MRS), or intramyocellular lipids (1H MRS), to give only a few examples. The observation of intramyocellular lipids (IMCL) by means of 1H MRS is non-invasive and, therefore, can be repeated many times and with a high temporal resolution. MRS has the potential to replace the biopsy for the monitoring of IMCL levels; however, the biopsy still has the advantage that other methods such as those used in molecular biology can be applied to the sample. The present study describes variations in the IMCL levels (expressed in mmol/kg wet weight and ml/100 ml) in three different muscles before and after (0, 1, 2, and 5 d) marathon runs for a well-trained individual who followed two different recovery protocols varying mainly in the diet. It was shown that the repletion of IMCL levels is strongly dependent on the diet post exercise. The monitoring of IMCL levels by means of 1H MRS is extremely promising, but several methodological limitations and pitfalls need to be considered, and these are addressed in the present review.

scholarly journals Brain Phosphorus Magnetic Resonance Spectroscopy Imaging of Sleep Homeostasis and Restoration in Drug Dependence

2007 ◽  
Vol 7 ◽  
pp. 217-222 ◽  
Author(s):  
George H. Trksak ◽  
J. Eric Jensen ◽  
Perry F. Renshaw ◽  
Scott E. Lukas
Keyword(s):  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Sleep Deprivation ◽  
High Energy ◽  
Nucleoside Triphosphate ◽  
Resonance Spectroscopy ◽  
Phosphorus Magnetic Resonance Spectroscopy ◽  
Control Subjects ◽  
Recovery Sleep ◽  
Drug Dependent

Numerous reports have documented a high occurrence of sleep difficulties in drug-dependent populations, prompting researchers to characterize sleep profiles and physiology in drug abusing populations. This mini-review examines studies indicating that drug-dependent populations exhibit alterations in sleep homeostatic and restoration processes in response to sleep deprivation. Sleep deprivation is a principal sleep research tool that results in marked physiological challenge, which provides a means to examine sleep homeostatic processes in response to extended wakefulness. A report from our laboratory demonstrated that following recovery sleep from sleep deprivation, brain high-energy phosphates particularly beta–nucleoside triphosphate (beta-NTP) are markedly increased as measured with phosphorus magnetic resonance spectroscopy (MRS). A more recent study examined the effects of sleep deprivation in opiate-dependent methadone-maintained (MM) subjects. The study demonstrated increases in brain beta-NTP following recovery sleep. Interestingly, these increases were of a markedly greater magnitude in MM subjects compared to control subjects. A similar study examined sleep deprivation in cocaine-dependent subjects demonstrating that cocaine-dependent subjects exhibit greater increases in brain beta-NTP following recovery sleep when compared to control subjects. The studies suggest that sleep deprivation in both MM subjects and cocaine-dependent subjects is characterized by greater changes in brain ATP levels than control subjects. Greater enhancements in brain ATP following recovery sleep may reflect a greater disruption to or impact of sleep deprivation in drug dependent subjects, whereby sleep restoration processes may be unable to properly regulate brain ATP and maintain brain high-energy equilibrium. These studies support the notion of a greater susceptibility to sleep loss in drug dependent populations. Additional sleep studies in drug abusing populations are needed, particularly those that examine potential differential effects of sleep deprivation.

Noninvasive assessment of pharmaceutical intervention during myocardial ischemia-reperfusion in a canine model using two-dimensional 31P chemical shift imaging

1998 ◽  
Vol 76 (2-3) ◽  
pp. 522-531 ◽  
Author(s):  
Constance M Campbell ◽  
Gerald Wisenberg ◽  
Jane Sykes ◽  
R Terry Thompson
Keyword(s):  
Magnetic Resonance ◽  
Myocardial Ischemia ◽  
Magnetic Resonance Spectroscopy ◽  
Infarct Size ◽  
Inverse Correlation ◽  
High Energy ◽  
Metabolic Effects ◽  
Resonance Spectroscopy ◽  
High Energy Phosphates ◽  
Early Reperfusion

The metabolic effects during myocardial ischemia and sustained reperfusion of the antianginal agents diltiazem (n = 10) and propranolol (n = 10) were monitored with noninvasive phosphorus nuclear magnetic resonance spectroscopy to establish any correlation between metabolic changes and infarct size. Spectroscopy followed changes in high-energy phosphate concentrations and myocardial intracellular pH during 2 h of left anterior descending coronary artery occlusion and 3 subsequent weeks of reperfusion, in a closed chest canine infarct model. Gadolinium-DTPA enhanced magnetic resonance imaging was used to assess the extent of myocardial injury (infarct size). Microspheres were used to document the zone at risk and the success of reperfusion. Whereas diltiazem appeared to reduce the derangement in high-energy phosphates during coronary occlusion, there was no significant change in infarct size when compared with a previously studied control group. Propranolol, which produced a lesser decline in pH during occlusion and smaller pH changes during early reperfusion, was associated with a significant reduction in the degree of tissue necrosis (compared with controls). There was an inverse correlation (r = -0.51) between the change in myocardial pH (occlusion end to immediate reperfusion) and the recovery index (an index of myocardial salvage). By 1 h into reperfusion, there was a stronger inverse correlation between pH and infarct size (r = -0.75), implying a protective effect of delaying pH recovery during early reperfusion and indicating the potential use of this parameter as a predictor of tissue viability.Key words: diltiazem, propranolol, magnetic resonance spectroscopy, myocardial infarction.

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