Selli, C.Erac, Y.Tosun, M.2019-10-272019-10-2720141537-18911879-3649https://doi.org/10.1016/j.vph.2014.03.008https://hdl.handle.net/11454/50140We previously showed that endothelin A (ETA) receptor antagonist BQ-123 partially inhibited cyclopiazonic acid (CPA)-enhanced endothelin-1 (ET-1)-induced contractions suggesting enhancement of ETA receptor internalization in caveolar structures by sarco/endoplasmic reticulum Ca+2 ATPase (SERCA) blockade. Since serotonin (5-Hydroxytryptamine, 5-HT) receptors are reported to be localized on caveolar membranes, we investigated whether SERCA inhibition affects 5-HT-induced responses and 5-HT receptor antagonism. For this purpose, vascular responses were measured in thoracic aorta segments from male Wistar albino rats using isolated tissue experiments. Data showed that CPA inhibits 5-HT- and PE-induced contractions in intact vessels while potentiating those in endothelium-denuded. Furthermore, non-selective 5-HT receptor blocker methysergide partially inhibited CPA-induced 5-HT contractions. However, alpha(1)-adrenergic receptor antagonist prazosin totally inhibited CPA-potentiated PE contractions. We suggest that SERCA inhibition results in 5-HT receptor internalization similar to ETA receptors possibly through protein kinase C activation by increased subsarcolemmal Ca2+ levels, eventually preventing 5-HT receptor antagonism. (C) 2014 Elsevier Inc All rights reserved.en10.1016/j.vph.2014.03.008info:eu-repo/semantics/closedAccessCaveolaeReceptor internalizationMethysergideArticle6102.Mar4348WOS:00033655760000124704610Q1Q1