Blood pressure variability provokes vascular p-adrenoceptor desensitization in rats

Autor(es)

Rocha, Matheus L. ^[1] ; Silva, Bruno R. ^[2] ; Lunardi, Claure N. ^[3] ; Ramalho, Leandra N. Z. ^[4] ; Bendhack, Lusiane M. ^[2]

Afiliação do(s) autor(es)

^[1] Univ Fed Goias, Fac Pharm, FF UFG, Goiania, Go - Brazil

^[2] FCFRP USP, Dept Chem & Phys, Fac Pharmaceut Sci, Ribeirao Preto, SP - Brazil

^[3] Univ Brasilia, Sch Hlth Sci, Fac Ceilandia, Brasilia, DF - Brazil

^[4] FMRP USP, Sch Med, Dept Pathol & Legal Med, Ribeirao Preto, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: VASCULAR PHARMACOLOGY; v. 82, p. 82-89, JUL 2016.
• Citações Web of Science: 1

Resumo

Spontaneous variation in blood pressure is defined as `blood pressure variability' (BPV). Sinoaortic denervation (SAD) is characterized by BPV without sustained hypertension. In the present study, we investigated whether BPV could be related to vascular beta-adrenoceptor desensitization in rats. Three days after surgery (SAD and control), aortic rings were placed in an organ chamber and the relaxation stimulated by P-adrenoceptor agonists, isoprenaline, terbutaline, BRL37344 and cyanopindolol was verified. The participation of intracellular nucleotides signaling pathways was also verified using forskolin, sodium nitroprusside and acetylcholine to induce relaxation. The effects of BPV on the increase in endothelial cytosolic Ca2+ concentration stimulated by the beta(2)-adrenoceptor agonist was examined by confocal microscopy. In addition, the vascular expression of the beta(2)-adrenoceptor was also examined by immunohistochemistry. The results show that isoprenaline and terbutaline-induced relaxation was lower in the aortas of rats with BPV. Relaxation responses to other vasorelaxant compounds were similar in both groups of rats. Histological analysis revealed a lower level of beta(2)-adrenoceptor and confocal microscopy showed minor cytosolic Ca2+ concentration in endothelial cells stimulated by the beta(2)-adrenoceptor agonist in rats with BPV. In conclusion, BPV leads to desensitization of the beta(2)-adrenoceptor, which could contribute to worse beta-adrenoceptor agonist-induced relaxation in isolated aortas. (C) 2016 Elsevier Inc. All rights reserved. (AU)

• Processo FAPESP: 04/09739-0 - Estudo da atividade oscilatória em aorta isolada de ratos submetidos à desnervação sino-aórtica
• Beneficiário: Matheus Lavorenti Rocha
• Modalidade de apoio: Bolsas no Brasil - Doutorado