Phosphorus nuclear magnetic resonance studies on the effect of duration of contraction in bull-frog skeletal muscles.
Y Kawano,M Tanokura,Yamada K +2 more
28
TL;DR: The time course of Pi recovery was well described by a single exponential and the amount of PCr hydrolysed (‐delta PCr), associated with contractions of various durations, coincided well with Pi increase (delta Pi).
read more
Abstract: 1. Contraction and recovery of bull-frog skeletal muscles were studied using 31P nuclear magnetic resonance (NMR), with a time resolution of 16 s, at 4 degrees C. The muscles were stimulated tetanically for various periods (0.2-10 s) at a sarcomere length of 2.4 microns. Changes in the concentrations of inorganic phosphate (Pi), phosphocreatine (PCr) and other metabolites were studied for repeated cycles of contraction and recovery. 2. In resting muscles, bathed in a solution gassed with 95% O2 and 5% CO2, the concentration of Pi was 1.15 +/- 0.21 mmol kg-1 wet weight (mean +/- one S.D., n = 12), that of ATP was 3.32 +/- 0.15 mmol kg-1 (mean +/- one S.D., n = 12) and that of sugar phosphates was less than 0.5 mmol kg-1. The intracellular pH (pHi) was 7.22 +/- 0.01 (mean +/- one S.D., n = 12). These results are averages for fibres which probably have different values. 3. On stimulating the muscles pHi shifted in the alkaline direction and subsequently recovered. The extent of the alkaline shift was linearly related to the contraction duration (0.2-10 s) with a rate of 0.01 pH unit s-1. 4. The increase in Pi with stimulus duration was biphasic, consisting of an early burst, 0.38 +/- 0.10 mmol kg-1 (+/- 1 S.D., n = 5), complete within about 0.2-0.5 s, followed by a slower steady-state increase. The steady-state rate of Pi increase was 0.33 +/- 0.02 mmol kg-1 s-1 (+/- 1 S.D., n = 5) in agreement with the results of previous studies involving chemical analyses. 5. The time course of Pi recovery was well described by a single exponential. Intensities of ATP, sugar phosphates and the peaks in the phosphodiester region did not change during a 2 s tetanus. 6. The amount of PCr hydrolysed (-delta PCr), associated with contractions of various durations, coincided well with Pi increase (delta Pi). This was found during the whole recovery period except for the initial few minutes following relaxation when -delta PCr was significantly smaller than delta Pi. The difference was 0.35 +/- 0.03 mmol kg-1 (mean +/- 1 S.D., n = 3) immediately after a 2 s tetanus. 7. In contractions of 2 s or longer, the extent of the temporal separation between delta Pi and -delta PCr was almost the same, but in contractions of less than 2 s it was significantly reduced.(ABSTRACT TRUNCATED AT 400 WORDS)
read more
Chat with Paper
AI Agents for this Paper
Find similar papers on Google Scholar, PubMed and Arxiv
Write a critical review of this paper
Analyze citations of this paper to find unaddressed research gaps
Citations
Oxidative phosphorylation: regulation and role in cellular and tissue metabolism.
TL;DR: In this paper, the authors describe a pathway incorporating three consecutive near equilibrium steps for moving reducing equivalents between the intramitochondrial [NAD+ ]/[NADH] pool to molecular oxygen, with irreversible reduction of oxygen to bound peroxide at cytochrome c oxidase determining the net flux.
249
Tissue variation in the control of oxidative phosphorylation: implication for mitochondrial diseases.
TL;DR: This work determined the control coefficients of seven OXPHOS complexes on the oxygen-consumption flux in rat mitochondria isolated from five different tissues under identical experimental conditions and proposed that this variation in control coefficient according to the tissue origin of the mitochondria can explain part of the tissue specificity observed in mitochondrial cytopathies.
Force-velocity relation for frog muscle fibres: effects of moderate fatigue and of intracellular acidification.
N. A. Curtin,K. A. P. Edman +1 more
TL;DR: Force was reduced more than stiffness indicating that, on average, there is less force per attached cross‐bridge in fatigue, and the force‐lengthening velocity relation showed that the ability to resist forces greater than isometric was well preserved in fatigue.
75
Glycerol phosphorylcholine (GPC) and serine ethanolamine phosphodiester (SEP): evolutionary mirrored metabolites and their potential metabolic roles
TL;DR: A further examination of the literature suggests a common role for all WSPDE as lysophospholipase inhibitors and therefore net sparers of phospholipids by decreasing phospholIPid metabolic throughput.
39
Recovery after contraction of white muscle fibres from the dogfish Scyliorhinus canicula.
TL;DR: Recovery after contraction of white muscle fibres of dogfish was investigated using 31P-NMR and measurements of heat production, showing that recovery was very slow, requiring at least 60 min for PCr resynthesis and for the production of recovery heat.
35
References
Control of muscle contraction
TL;DR: As is well known, the memorable discovery of Galvani (1791) was followed by the development of two new fields of science, electrochemistry and electrophysiology, which resulted in a marked progress of physiological and morphological studies which were intentionally or unintentionally concerned with the mechanism of the link between excitation at the surface membrane, and the contractile process.
800
Observation of tissue metabolites using 31P nuclear magnetic resonance.
D. I. Hoult,Stephen J. W. Busby,D. G. Gadian,George K. Radda,Rex Edward Richards,P.J. Seeley +5 more
TL;DR: 31P NMR spectra of intact biological tissues can now be observed and the use of the spectra to study the course of reactions within the tissues is illustrated by experiments on muscle and its glycogen particle fraction.
637
The activity of creatine-kinase in frog skeletal-muscle studied by saturation transfer nuclear magnetic-resonance
Truman R. Brown,Em Chance,Mj Dawson,Dg Gadian,G. K. Radda,Wilkie +5 more
- 01 Jan 1980
TL;DR: The observed constancy of phosphocreatine demonstrates that the enzyme and its substrates are at equilibrium, and the observation that the forward flux does not increase during contraction and that the backward flux decreases can most simply be explained on the basis of competition of reactants for a limited amount of enzyme.
150
Relationship between mitochondria and oxygen consumption in isolated cat muscles.
TL;DR: It was found that mitochondrial structure was similar in muscles with different oxidative capacities and that equal amounts of mitochondria consumedequal amounts of oxygen under limiting conditions of maximal in vivo respiration.
122
Electron probe X-ray microanalysis of post-tetanic Ca2+ and Mg2+ movements across the sarcoplasmic reticulum in situ.
TL;DR: The return of the Mg2+ taken up by the terminal cisternae during a tetanus to resting levels was significantly slower than the time course of the Ca2+ movements, suggesting that the Mm2+ permeability of the SR in situ is low and may be transiently increased during tetanic stimulation.
114