alpha7B integrin changes in mdx mouse muscles after L-arginine administration.

Muscle fibers attach to laminin in the basal lamina using two mechanisms, i.e., dystrophin with its associated proteins and alpha7beta1 integrin. In humans, gene-mutation defects in one member of these complexes result in muscular dystrophies. This study revealed changes after L-arginine treatment of utrophin-associated proteins and the alpha7B integrin subunit in mdx mouse, a dystrophin-deficient animal model. In the two studied muscles (cardiac muscle and diaphragm), the alpha7B integrin subunit was increased in 5-week-old treated mice. Interestingly, the diaphragm histopathological appearance was significantly improved by L-arginine administration. These results highlight a possible way to compensate for dystrophin deficiency via alpha7beta1 integrin.