{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,20]],"date-time":"2026-04-20T16:39:07Z","timestamp":1776703147192,"version":"3.51.2"},"reference-count":26,"publisher":"American Physiological Society","issue":"6","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["American Journal of Physiology-Cell Physiology"],"published-print":{"date-parts":[[2004,12]]},"abstract":"<jats:p> The \u03b2<jats:sub>2<\/jats:sub>-adrenergic receptor (\u03b2<jats:sub>2<\/jats:sub>-AR) and the large-conductance Ca<jats:sup>2+<\/jats:sup>-activated K<jats:sup>+<\/jats:sup> (BK<jats:sub>Ca<\/jats:sub>) channel have been shown, separately, to be involved in mediating uterine relaxation. Our recent studies reveal that the levels of both \u03b2<jats:sub>2<\/jats:sub>-AR and BK<jats:sub>Ca<\/jats:sub> channel proteins in pregnant human myometrium decrease by \u223c50% after the onset of labor. We present direct evidence in support of a structural and functional association between the \u03b2<jats:sub>2<\/jats:sub>-AR and the BK<jats:sub>Ca<\/jats:sub> channel in pregnant human myometrium. Localization of both proteins is predominantly plasmalemmal, with 60% of \u03b2<jats:sub>2<\/jats:sub>-AR colocalizing with the BK<jats:sub>Ca<\/jats:sub> channel. Coimmunoprecipitation studies indicate that BK<jats:sub>Ca<\/jats:sub> and \u03b2<jats:sub>2<\/jats:sub>-AR are structurally linked by direct protein-protein interactions. Functional correlation was confirmed by experiments of human myometrial contractility in which the BK<jats:sub>Ca<\/jats:sub> channel blocker, paxilline, significantly antagonized the relaxant effect of the \u03b2<jats:sub>2<\/jats:sub>-AR agonist ritodrine. These novel findings provide an insight into the coupling between the \u03b2<jats:sub>2<\/jats:sub>-AR and BK<jats:sub>Ca<\/jats:sub> channel and may have utility in the application of this signaling cascade for therapeutic potential in the management of preterm labor. <\/jats:p>","DOI":"10.1152\/ajpcell.00236.2004","type":"journal-article","created":{"date-parts":[[2004,8,26]],"date-time":"2004-08-26T00:18:03Z","timestamp":1093479483000},"page":"C1747-C1752","source":"Crossref","is-referenced-by-count":45,"title":["Contribution of coupling between human myometrial \u03b2<sub>2<\/sub>-adrenoreceptor and the BK<sub>Ca<\/sub> channel to uterine quiescence"],"prefix":"10.1152","volume":"287","author":[{"given":"Boonsri","family":"Chanrachakul","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Fiona","family":"Broughton Pipkin","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Raheela N.","family":"Khan","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"24","reference":[{"key":"R1","doi-asserted-by":"crossref","unstructured":"American College of Obstetricians and Gynecologists. 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