Biochemical studies of isolated mitochondria from normal and diseased tissues.

Isolated mitochondria have served as useful tools for identifying the site(s) of impairment associated with respiratory chain-linked oxidative phosphorylation at the molecular level. Over the last three decades, a number of diseases associated with mitochondrial dysfunction have been identified. The literature is large and diverse. This paper presents a brief survey of the current state of knowledge concerning biochemical studies of mitochondrial diseases associated with skeletal muscle, such as mitochondrial myopathies and, with brain injury such as that induced by ischemia/reperfusion. Various mitochondrial preparations and assay conditions are evaluated. The importance of fresh tissue for the isolation of tightly coupled mitochondria and the selection of suitable assay conditions for characterization have been demonstrated. Appropriate methodologies for isolation and characterization of tightly coupled mitochondria from both skeletal muscle and brain are presented.