An ultrastructural study of isolated rat skeletal muscle mitochondria in various metabolic states.

An electron microscopic examination was made of isolated rat skeletal muscle mitochondria in various functional states. Shifts in the inner membrane ultrastructure of populations of mitochondria were observed under certain conditions. However, ultrastructural transformations reported by others during rapid changes in biochemical states were not observed in skeletal muscle mitochondria. There does not appear to be a strict correlation between metabolic states and ultrastructural states in isolated rat skeletal muscle mitochondria as has been observed in isolated mitochondria from several other tissue types.