Development of Sulfonylurea-Sensitive Regulatory Parts of Potassium Channels in Pregnant Rat Uterus Muscle

SUR1 levels in the pregnant rat myometrium increased markedly by day 6 of pregnancy before declining in later stages.

• SUR1 and SUR2 are subunits of ATP-sensitive potassium channels that may play a role in uterine contractility during pregnancy.
• SUR1 expression significantly rises during early pregnancy, peaking on day 6, while SUR2 levels remain stable throughout.
• Oxytocin-induced contractions can be inhibited by both diazoxide, which targets SURs non-selectively, and pinacidil, which selectively targets SUR2.
• The K(ATP) channel blocker glibenclamide counteracts the relaxing effects of both pinacidil and diazoxide.
• SURs are suggested to be key in the pharmacological response of K(ATP) channel openers in the myometrium.

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