Energy metabolism in selected physical exercises

Abstract Based on earlier few studies natural metabolite D-glyceric acid does not seem to play any major role in cellular metabolism. Nevertheless, one study that concentrated on ethanol oxidation in the liver increased our curiosity. Therefore, research leading to the present 25 days lasting double blinded human study with placebo control was initiated. Main targets in the present study were: 1) to find out whether acute and long-term exogenous D-glyceric acid (DGA) regimen will cause activation related to energy metabolism in healthy 50-60-year old humans, and 2) to find out whether elevated levels of endogenous DGA can be found in the plasma after 30 min of a strenuous cycling exercise. Additional target was to find out whether certain effects of exogenous DGA regimen resemble the effects of physical exercises, and whether lowered halved dose of DGA regimen during a 14-day follow-up period continues to be effective. The main results revealed that: I) there was an acute effect on plasma glucose maintenance from DGA regimen, II) plasma metabolites and gene expressions related to aerobic energy production were strongly modulated, and subclinical inflammation was lowered already after the 4-day DGA regimen, and III) cycling with increasing load towards exhaustion increased endogenous levels of DGA in human plasma (p=0.013). Because the amounts of administered DGA were exceedingly small and cannot directly have caused observed substantial changes, we hypothesise that an increase in tissue DGA concentration causes an endogenous signal or a cascade of intracellular signals: “ more ATP is needed immediately ”. At the whole body level, the signal causes metabolic activation cascade that resembles initiation of physical exercises but without literally no signs of exhaustion. Tested exogenous DGA regimen possessed an effect even on circulating immune cells. Based on obtained results, the DGA regimen may facilitate in resolving energy metabolic challenges in main organs, like fatty liver, and simultaneously it seemed to lower systemic inflammation. The DGA regimen can possibly alleviate chronic diseases and disorders related to energy metabolism and/or elevated subclinical inflammation.Trial registration number (18th of Jan 2021), ClinicalTrials.gov Identifier: NCT04713319

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Mitochondrial matrix calcium ions regulate energy production in myocardium: A cytochemical study

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100134429 ◽

1990 ◽

Vol 48 (2) ◽

pp. 166-167

Author(s):

W.A. Jacob ◽

R. Hertsens ◽

A. Van Bogaert ◽

M. De Smet

Keyword(s):

Energy Metabolism ◽

Calcium Ions ◽

Energy Production ◽

Regulation Of Respiration ◽

Free Calcium ◽

Mitochondrial Matrix ◽

Cytochemical Study ◽

Nmr Techniques

In the past most studies of the control of energy metabolism focus on the role of the phosphorylation potential ATP/ADP.Pi on the regulation of respiration. Studies using NMR techniques have demonstrated that the concentrations of these compounds for oxidation phosphorylation do not change appreciably throughout the cardiac cycle and during increases in cardiac work. Hence regulation of energy production by calcium ions, present in the mitochondrial matrix, has been the object of a number of recent studies.Three exclusively intramitochondnal dehydrogenases are key enzymes for the regulation of oxidative metabolism. They are activated by calcium ions in the low micromolar range. Since, however, earlier estimates of the intramitochondnal calcium, based on equilibrium thermodynamic considerations, were in the millimolar range, a physiological correlation was not evident. The introduction of calcium-sensitive probes fura-2 and indo-1 made monitoring of free calcium during changing energy metabolism possible. These studies were performed on isolated mitochondria and extrapolation to the in vivo situation is more or less speculative.

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