Design of the mammalian respiratory system. VII. Scaling mitochondrial volume in skeletal muscle to body mass

High fatty acid oxidation capacity and phosphorylation control despite elevated leak and reduced respiratory capacity in northern elephant seal muscle mitochondria

“…This is consistent with a lower respiratory capacity of adult NES versus human muscle per unit mass, as would be predicted by the well-established inverse relationship between muscle mitochondrial volume density and body mass across mammalian species (Mathieu et al, 1981;Dobson and Headrick, 1995). However, the highly variable relative differences in respiratory flux between seals and humans highlights the importance of considering substrate utilization and multiple respiratory states when evaluating adaptive changes in muscle aerobic capacity.…”

Symmorphosis and the insect respiratory system: a comparison between flight and hopping muscle

“…It is also inconsistent with several studies on mammals, where aerobic capacity appears to be completely dependent upon the volume of mitochondria in the skeletal muscles (Else and Hulbert, 1985;Hoppeler et al, 1987;Mathieu et al, 1981;Schwerzmann et al, 1989;Weibel et al, 2004).…”

Symmorphosis and the insect respiratory system: allometric variation

“…Taylor and Weibel predicted that if their theory of symmorphosis holds for the mammalian respiratory system, then maximum oxygen uptake should scale with an exponent (b) that is statistically indistinguishable from the exponents derived for each of the structural variables . They found that maximum oxygen consumption rate scales with body mass with an exponent of 0.80 , and that this is congruent with the allometric scaling of mitochondrial volume in the diaphragm and locomotory muscles, b0.80 to 0.82 (Mathieu et al, 1981). It was also established that total capillary length in selected muscles scales roughly parallel with aerobic capacity, b0.86 to 0.91, but because of scatter in the data it was not possible to determine whether the slopes were statistically similar (Hoppeler et al, 1981b;Weibel et al, 1981a).…”

“…First, the functional capacity of the respiratory system was determined by measuring the maximum oxygen consumption rate of mammals during exercise of progressive increasing intensity . Next, a number of structural variables crucial in the delivery and consumption of oxygen during exercise were morphometrically quantified Hoppeler et al, 1981a;Hoppeler et al, 1981b;Mathieu et al, 1981;Weibel et al, 1981b). The effect of body mass on the maximum oxygen consumption rate of mammals and the amount of respiratory structure they possess was expressed as an allometric equation, yaM b b , where y is the variable of interest, a is the coefficient, M b is body mass and b is the scaling exponent.…”