Browsing by Author "Heinle, H. (7003342814)"

The ideal agent for prevention and treatment of uterine abnormal contractility has not been found. The polyphenol resveratrol possesses a wide spectrum of pharmacologic properties, but its influence on the contractility of human myometrium is not defined. The present study evaluated the effect of resveratrol on the oxytocin-induced contractions of human term pregnant myometrium in vitro and the contribution of different K+ channels to resveratrol action. Resveratrol induced a concentration-dependent relaxation of myometrium contractions (pD2 value and maximal responses were 4.52 and 82.25%, respectively). Glibenclamide, a selective blocker of ATP-sensitive (KATP), iberiotoxin, a selective blockers of big-calcium sensitive (BKCa) and 4-aminopiridine, a non-selective blocker of voltage-sensitive (Kv) channels induced a significant shift to the right of the concentration-response curves of resveratrol. Inhibition achieved by 0.1 mM resveratrol was insensitive to all K+ channel blockers. A K+ channel opener, pinacidil, inhibited oxytocin-induced contractions of pregnant myometrium with comparable potency and efficacy to resveratrol (pD2 values and maximal relaxation were 4.52 and 83.67%, respectively). Based on K+ channel opener/blocker affinities, it appears that the inhibitory response of resveratrol involves different myometrial K+ channels. When applied in high concentrations, resveratrol has an additional K+-channel-independent mechanism(s) of action. Furthermore, immunohistochemistry staining and western blot analyses detected the presence and distribution of KATP, BKCa and Kv channel proteins in pregnant myometrium. © The Author 2015. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved.