Sarcoplasmic reticulum Ca permeation explored from the lumen side in mdx muscle fibers under voltage control

Duchenne muscular dystrophy is a very severe muscle disease that is characterized by progressive skeletal muscle wasting. Duchenne muscular dystrophy is provoked by mutations in the gene encoding the protein dystrophin, which lead to the total absence of this protein in skeletal muscles. In normal skeletal muscle, dystrophin is located underneath the sarcolemma, and interacts with the F-actin component of the intracellular cytoskeleton at its N-terminal extremity and with a sarcolemmal-embedded glycoprotein complex at its C-terminal extremity, which itself is associated with the extracellular matrix (Blake et al., 2002). Lack of dystrophin is assumed to destabilize this architecture and to promote disruption of the linkage between the subsarcolemmal cytoskeleton and the extracellular matrix, but the functional consequences of the absence of dystrophin that contribute to muscle degeneration still remain elusive. Mainly with the help of the mdx mouse model, which also lacks dystrophin, several studies have nevertheless put forward the idea that degeneration of dystrophin-deficient skeletal