POMC-derived peptides in the neuromuscular system of streptozotocin-diabetic mice.

Immunoreactivity for beta-endorphin and alpha-MSH/ACTH was demonstrated in intramuscular nerves in soleus, extensor digitorum longus, and diaphragm muscles of normal and streptozotocin-diabetic mice. There was a higher incidence of immunoreactive nerves in the muscles of the diabetic mice. Specific binding for [125I]ACTH was detected in a proportion of the muscle fibers, using autoradiography. There were significantly more fibers with specific [125I]beta-endorphin sites and specific [125]ACTH sites in some muscles in the diabetic mice. The increased expression of POMC-derived peptides and their receptors in the neuromuscular system of streptozotocin-diabetic mice may indicate early neuropathic change.