Functional Coupling of β3-Adrenoceptors and Large Conductance Calcium-Activated Potassium Channels in Human Uterine Myocytes

Context: 3-Adrenoreceptor modulation in human myometrium during pregnancy is linked functionally to myometrial inhibition. Maxi-K channels (BKCa) play a significant role in modulating cell membrane potential and excitability. Objective: This study was designed to investigate the potential involvement of BKCa channel function in the response of human myometrium to 3-adrenoceptor activation. Design: Single and whole-cell electrophysiological BKCa channel recordings from freshly dispersed myocytes were obtained in the presence and absence of BRL37344, a specific 3-adrenoreceptor agonist. The in vitro effects of BRL37344 on isolated myometrial contractions, in the presence and absence of the specific BKCa channel blocker, iberiotoxin (IbTX), were investigated.