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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

STIM 1/Orai 1 contributes to sex differences in vascular responses to calcium in spontaneously hypertensive rats

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Author(s):
Giachini, Fernanda R. C. [1] ; Lima, Victor V. [2] ; Filgueira, Fernando P. [3] ; Dorrance, Anne M. [4] ; Carvalho, Maria Helena C. [5] ; Fortes, Zuleica B. [6] ; Webb, R. Clinton [7] ; Tostes, Rita C. [8]
Total Authors: 8
Affiliation:
[1] Georgia Hlth Sci Univ. Dept Physiol
[2] Georgia Hlth Sci Univ. Dept Physiol
[3] Univ Sao Paulo. Dept Pharmacol
[4] Michigan State Univ. Dept Pharmacol & Toxicol
[5] Univ Sao Paulo. Dept Pharmacol
[6] Univ Sao Paulo. Dept Pharmacol
[7] Georgia Hlth Sci Univ. Dept Physiol
[8] Georgia Hlth Sci Univ. Dept Physiol
Total Affiliations: 8
Document type: Journal article
Source: Clinical Science; v. 122, n. 5-6, p. 215-226, MAR 2012.
Web of Science Citations: 15
Abstract

Sex differences in Ca2+-dependent signalling and homoeostasis in the vasculature of hypertensive rats are well characterized. However, sex-related differences in SOCE (store-operated Ca2+ entry) have been minimally investigated. We hypothesized that vascular protection in females, compared with males, reflects decreased Ca2+ mobilization due to diminished activation of Orai 1/STIM 1 (stromal interaction molecule I). In addition, we investigated whether ovariectomy in females affects the activation of the Orai 1/STIM 1 pathway. Endothelium-denuded aortic rings from male and female SHRSP (stroke-prone spontaneously hypertensive rats) and WKY (Wistar Kyoto) rats and from OVX (ovariectomized) or sham female SHRSP and WKY rats were used to functionally evaluate Ca2+ influx-induced contractions. Compared with females, aorta from male SHRSP displayed: (i) increased contraction during the Ca2+-loading period; (ii) similar transient contraction during Ca2+ release from the intracellular stores; (iii) increased activation of STIM 1 and Orai1, as shown by the blockade of STIM 1 and Orai1 with neutralizing antibodies, which reversed the sex differences in contraction during the Ca2+-loading period; and (iv) increased expression of STIM I and Orai I. Additionally, we found that aortas from OVX-SHRSP showed increased contraction during the Ca2+-loading period and increased Orai1 expression, but no changes in the SR (sarcoplasmic reticulum)-buffering capacity or STIM I expression. These findings suggest that augmented activation of STIM 1/Orai 1 in aortas from male SHRSP represents a mechanism that contributes to sex-related impaired control of intracellular Ca2+ levels. Furthermore, female sex hormones may negatively modulate the STIM/Orai 1 pathway, contributing to vascular protection observed in female rats. (AU)

FAPESP's process: 09/08095-5 - Sexual differences in STIM/Orai signaling in the vasculature of spontaneusly hypertensive rats
Grantee:Rita de Cassia Aleixo Tostes Passaglia
Support Opportunities: Regular Research Grants