Effects of cyclopiazonic acid and dexamethasone on serotonin-induced calcium responses in vascular smooth muscle cellsReport as inadecuate




Effects of cyclopiazonic acid and dexamethasone on serotonin-induced calcium responses in vascular smooth muscle cells - Download this document for free, or read online. Document in PDF available to download.

Journal of Physiology and Biochemistry

, Volume 72, Issue 2, pp 245–253

First Online: 04 March 2016Received: 20 October 2015Accepted: 20 January 2016DOI: 10.1007-s13105-016-0474-8

Cite this article as: Selli, C. & Tosun, M. J Physiol Biochem 2016 72: 245. doi:10.1007-s13105-016-0474-8

Abstract

We previously observed that sarcoendoplasmic reticulum Ca ATPase SERCA blockade by cyclopiazonic acid CPA significantly potentiates serotonin 5-hydroxytryptamine 5-HT-induced vascular contractions. Furthermore, 5-HT receptor antagonist methysergide partially inhibited CPA-potentiated 5-HT contractions. In the present study, we further investigated whether SERCA inhibition potentiates 5-HT-induced Ca responses along with attenuating the receptor antagonism by store-operated Ca SOC entry and protein kinase C PKC-mediated mechanisms. The effects of dexamethasone that was previously shown to induce SOC entry and enhance 5-HT responses were also tested. For this purpose, intracellular Ca levels were monitored in A7r5 embryonic rat vascular smooth muscle cells by spectrofluorometry using the fluorescent indicator fura-2. The results showed that CPA, although not dexamethasone, significantly potentiated 5-HT-induced Ca elevations. Ketanserin partially decreased 5-HT-induced and CPA-potentiated Ca elevations whereas both PKC inhibitor D-sphingosine and SOC entry blocker 2-aminoethoxydiphenyl borate 2-APB abolished the remaining responses. The data suggests that diminished antagonistic effect on 5-HT-induced Ca elevations in the presence of SERCA inhibition is induced by SOC entry and PKC activation.

KeywordsCPA Dexamethasone PKC Serotonin SOC  Download fulltext PDF



Author: Cigdem Selli - Metiner Tosun

Source: https://link.springer.com/







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