Arun M.Z.Reel B.Guzeloglu M.Albayrak G.Aykut K.Hazan E.2019-10-272019-10-2720141811-77751811-7775https://doi.org/10.3923/ijp.2014.501.506https://hdl.handle.net/11454/26248Bisphosphonates, including alendronate, are widely used for the treatment of osteoporosis, hypercalcemia and bone metastasis associated with cancer. However, recent evidence has demonstrated anti-atherosclerotic effects of bisphosphonates in animal models and atherosclerotic patients. Besides, some studies have shown that bisphosphonates change calciwn homeostasis in cardiomyocytes and interfere L-type calciwn chmels in vascular smooth muscle cells. Therefore, in the present study it was aimed to investigate the effects of alendronate on contractile responses and ATP-sensitive potassiwn channels in vitro in hwnan Left Internal Mammary Artery (LIMA). Hwnan LIMA rings were placed into isolated organ chambers. After resting period, rings were kept for an hour in incubation mediwn which contains alendronate (10-6 M) or not (control) and responses of the rings to the contractile agents were examined. The incubation of two rings was performed in the presence of glibenclamide which is ATP-sensitive potassiwn channel blocker (10-6M). Maximwn contractile responses of LIMA rings to noradrenalin and serotonin decreased in the presence of alendronate. In concomitant incubation of LIMA with alendronate and glibenclamide reversed decreased contractions to noradrenalin or serotonin caused by alendronate. However, neither alendronate nor glibenclamide changed sensitivity to noradrenaline or serotonin. The present findings point out that alendronate may change intracellular calciwn dynamics in hwnan LIMA, due to the activation of ATP-sensitive potassiwn channels which have an important role on cardiovascular system. © 2014 Asian Network for Scientific Informationen10.3923/ijp.2014.501.506info:eu-repo/semantics/openAccessAlendronateBisphosphonatesContractionLIMAPotassiwn channelsArticle108501506N/A