Proopiomelanocortin-derived peptides in mice with motoneurone disease.

beta-Endorphin and alpha-melanotropin immunoreactivity was detected in motor nerves in histological sections of murine skeletal muscle, using the peroxidase-antiperoxidase technique. In mice of the wobbler strain, which can inherit motoneurone disease, a significantly higher proportion of the intramuscular nerves in soleus, extensor digitorum longus and diaphragm muscles of the diseased mice were immunoreactive than in the corresponding muscles of their healthy littermates.