Stereological analysis of mammalian skeletal muscle (original) (raw)

A quantitative analysis of the fast-twitch-glycolytic fibers of the adult guinea pig muscle has been made using the methods of stereology. This allows correlations with biochemical and physiological data to be made. The structural components involved in oxidative metabolism are found in small amounts, namely the volume fraction of blood vessel is 0.8 ± 0.3%; that of lipid droplets is 0.012 ± 0.006%; and that of mitochondria is 1.91 ± 0.18%. The entire sarcoplasmic reticulum is extensive as expected for a fast-twitch fiber, the volume being 4.59 ± 0.29% and the surface area being 132.4 ± 7.7 ttmV100 #ms of the fiber volume. The sarcolemma has a surface area of 9.7 ± 0.7 #m2/100 #m 3 which is more than half the T system surface area of 14.6 ± 0.6 #m~/100 ttm 3. The volume fraction of the T system is 0.27 ± 0.02%. The Z line width is narrow, being 610 ± 10 /~. Other measured parameters include nuclear volume, fiber, and myofibril diameters.