Does intracellular metabolite diffusion limit post-contractile recovery in burst locomotor muscle?
TLDR
It is concluded that fiber SA:V and O2 flux exert more control than intracellular metabolite diffusive flux over the developmental changes in metabolic organization and metabolic fluxes that characterize these muscles.Abstract:
Post-metamorphic growth in the blue crab entails an increase in body mass that spans several orders of magnitude. The muscles that power burst swimming in these animals grow hypertrophically, such that small crabs have fiber diameters that are typical of most cells ( 600·µm). Thus, as the animals grow, their muscle fibers cross and greatly exceed the surface area to volume ratio (SA:V) and intracellular diffusion distance threshold that is adhered to by most cells. Large fiber size should not impact burst contractile function, but post-contractile recovery may be limited by low SA:V and excessive intracellular diffusion distances. A number of changes occur in muscle structure, metabolic organization and metabolic flux during development to compensate for the effects of increasing fiber size. In the present study, we examined the impact of intracellular metabolite diffusive flux on the rate of postcontractile arginine phosphate (AP) resynthesis in burst locomotor muscle from small and large animals. AP recovery was measured following burst exercise, and these data were compared to a mathematical reaction‐diffusion model of aerobic metabolism. The measured rates of AP resynthesis were independent of fiber size, while simulations of aerobic AP resynthesis yielded lower rates in large fibers. These contradictory findings are consistent with previous observations that there is an increased reliance on anaerobic metabolism for post-contractile metabolic recovery in large fibers. However, the model results suggest that the interaction between mitochondrial ATP production rates, ATP consumption rates and diffusion distances yield a system that is not particularly close to being limited by intracellular metabolite diffusion. We conclude that fiber SA:V and O2 flux exert more control than intracellular metabolite diffusive flux over the developmental changes in metabolic organization and metabolic fluxes that characterize these muscles.read more
Citations
More filters
Journal ArticleDOI
Do we underestimate the importance of water in cell biology
TL;DR: Water can generate small active clusters and macroscopic assemblies, which can both transmit information on different scales and allow water to execute an intricate three-dimensional 'ballet' while retaining complex order and enduring effects.
Journal ArticleDOI
Molecules in motion: influences of diffusion on metabolic structure and function in skeletal muscle
TL;DR: Experimental measurements of metabolic fluxes, diffusion distances and diffusion coefficients, coupled with reaction–diffusion mathematical models in a range of muscle types has started to reveal some general principles guiding muscle structure and metabolic function.
Journal ArticleDOI
Fishes of southern South America: a story driven by temperature
TL;DR: Biological and ecological data of marine and freshwater fishes from the southern Neotropics, including Patagonia, are reviewed, and several examples of dependence on temperature are reported, from glacial times to today’s climate change.
Journal ArticleDOI
The long and winding road: influences of intracellular metabolite diffusion on cellular organization and metabolism in skeletal muscle.
TL;DR: The effect of diffusion distance on O(2) flux in muscle has been the subject of quantitative analyses for a century, but the influence of ATP diffusion from mitochondria to cellular ATPases on aerobic metabolism has received much less attention as discussed by the authors.
Journal ArticleDOI
The influence of oxygen and high-energy phosphate diffusion on metabolic scaling in three species of tail-flipping crustaceans
TL;DR: An examination of the influence of O2 and HEP diffusion on the observed rate of aerobic flux in muscle revealed that diffusion limitation was minimal under most conditions, suggesting that diffusion might act on the evolution of fiber design but usually does not directly limit aerobic flux.
References
More filters
Journal ArticleDOI
Post-exercise lactate production and metabolism in three species of aquatic and terrestrial decapod crustaceans
TL;DR: Lactate recycling via gluconeogenesis and the potential role of carbonic anhydrase (CA) in supplying bicarbonate for the carboxylation of pyruvate were investigated in three species of decapod crustaceans.
Journal ArticleDOI
Diffusion of ATP in sperm flagella
TL;DR: Comparison of the calculated minimum ATP content with the measured content of ATP actually present in bull and sea urchin sperm showed that the minimum requirements are overfulfilled.
Journal ArticleDOI
Regulation of oxidative phosphorylation in different muscles and various experimental conditions
TL;DR: The idea of the parallel activation of ATP usage and different oxidative-phosphorylation complexes during muscle contraction can account for the following kinetic properties of oxidative phosphorylation in skeletal muscle encountered in different experimental studies.
Journal ArticleDOI
Cellular energetics analysis by a mathematical model of energy balance: estimation of parameters in human skeletal muscle
TL;DR: A new method of analysis of these processes in data from single individuals is devised based on the logic of current information on the major mechanisms involved in this energy balance and can quantify not directly measurable parameters that govern those mechanisms.
Journal ArticleDOI
Kinetic Studies on the Arginine Kinase Reaction
Elizabeth Smith,John F. Morrison +1 more
TL;DR: The results of initial velocity, product inhibition, and isotope exchange at equilibrium studies are consistent with the reaction having a random mechanism in which all the steps are in rapid equilibrium except those concerned with the interconversion of the central ternary complexes.