Sodium channels and transporters in the myometrium.

In excitable cells such as neurons and cardiomyocytes, sodium influx across the plasma membrane contributes to the resting membrane potential, and sodium is the key ion for generating action potentials. In myometrial smooth muscle cells, however, the functions of sodium influx have not been fully elucidated. This review briefly discusses the contribution of Na pumps to myometrial excitability but given the brevity of this article, we focus on the evidence that sodium influx through various types of channels may play numerous roles in controlling myometrial excitability.