Ion channels and the control of myometrial electrical activity.

Understanding the role of ion channels in the generation of slow waves and action potentials in the myometrium is critical in designing strategies to regulate uterine contractile activity. The development of the patch clamp technique has allowed the identification of specific types of channels in the myometrium and provided insights into their regulation by hormones and drugs. Specifically, new studies suggest that KATP and KCa channel openers could be important tools in the management of inappropriate uterine contractions, but peripheral effects will have to be controlled. Conversely, blockers of these same channels may have some effects on dystocia. The study of contractant-operated channels in the myometrium is still in its infancy, but promises new insights into possible modes of regulation as well. Myometrial activity is controlled at a number of levels. The regulation of ion channels is an important aspect, but receptor-mediated actions that do not appear to be voltage- or ion-dependent presumably are also important contributors and hence are sites of potential modulation as well. Clearly, future multifaceted approaches to tocolysis, and perhaps also dystocia, may well include agents targeting the activity of ion channels.