Subtypes of P2 Receptors in Rat Neuromuscular Junction.

At the neuromuscular junction, ATP and its metabolite adenosine regulate the release of acetylcholine by activating purinergic receptors (P2), thereby regulating the function of skeletal muscles under normal and pathological conditions. The presence of P2 receptors in the neuromuscular junction was assessed immunohistochemically on sections of m. soleus, m. extensor digitorum longus, and diaphragm muscle. Of the ionotropic P2X receptors, P2X1 and P2X2 subtypes showed high expression in the studied samples. Among the P2Y receptor family, only the P2Y13 subtype was expressed in the sections. This study provides new insight into the subtypes of purinergic receptors involved in controlling the cholinergic transmission in the mammalian neuromuscular system.