Sexual Differences In Relaxation Response Induced By The G Protein-Coupled Oestrogen Receptor (GPER) Agonist (G-1) In Isolated Resistance Mesenteric Arteries From SHR.

Sexual Differences In Relaxation Response Induced By The G Protein-Coupled Oestrogen Receptor (GPER) Agonist (G-1) In Isolated Resistance Mesenteric Arteries From SHR.

• Autor
• Nathalie Tristão Banhos Delgado**
• Co-autores
• Wender do Nascimento Rouver , Roger Lyrio dos Santos
• Resumo

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  Introduction: Hypertension is considered the risk factor for cardiovascular diseases with greater susceptibility in men when compared to premenopausal women. This difference is lost after menopause, indicating the cardioprotective effects of oestrogen that are mediated by classical receptors and G protein-coupled oestrogen receptor (GPER). However, little is known about the responses of GPER in the vascular system. Thus, we evaluated the GPER response in mesenteric arteries of resistance in hypertensive rats (SHR) of both sexes.

  Methods: The present study was approved (CEUA 048/2016). G-1 concentration-response curves (1 nM?10 ?M) were performed in mesenteric arteries from SHR of both sexes (10-12 weeks and 180–250 g). The effects of G-1 were evaluated before and after incubation for 30 min with nitric oxide synthase inhibitor (L-NAME, 300 ?M) alone or combined with cyclooxygenase inhibitor (Indomethacin, 10 ?M) or both combined with cytochrome P450 (CYP) inhibitor (Clotrimazole, 0.75 ?M) or H2O2 degradator, catalase. The data were expressed as mean ± SEM. Two-way ANOVA followed by Sidak's post-hoc test was used. p <0.05.

  Results: G-1 induced concentration-dependent relaxation without differences related to sex (Female= 83 ± 3%; Male= 75 ± 3%) and partially endothelium-dependent (Female= 60 ± 10%; Male= 53 ± 2%). When analyzing the participation of endothelial mediators, we found that the G-1 response in females does not depend on the NO pathways (79 ± 5%), unlike males (54 ± 7%), but there was an involvement of H2O2 in both sexes (Female= 47 ± 12% and Male= 75 ± 3%).

  Conclusion: The activation of GPER promotes relaxation in mesenteric arteries similarly between the sexes, but with greater participation of the NO pathway in males and H2O2 in females. These results raise functional evidence that contributes to a better understanding of GPER activation and suggest G-1 as a potential therapeutic target in hypertension.

• Palavras-chave
• GPER, hypertension, mesenteric resistance arteries.
• Modalidade
• Pôster
• Área Temática
• Sistema endócrino e doenças vasculares