Evaluation of the Anticontractile Effect of the Perivascular Adipose Tissue in the Thoracic Aorta of DOCA-salt Rats.

Evaluation of the Anticontractile Effect of the Perivascular Adipose Tissue in the Thoracic Aorta of DOCA-salt Rats.

• Autor
• Montone, B.1*
• Co-autores
• Couto, G.K.1 , de Paula, R.B.1** , Rossoni, L.V.1
• Resumo

•  

   

   

   

   

  Introduction: Perivascular adipose tissue (PVAT) surrounds most of the blood vessels and modulates the contractile vascular response to stimulation with different agonists, the so-called anticontractile effect (AE). However, PVAT is dysfunctional in hypertension, with loss of this effect. Both ?- and ?-adrenergic receptors (AR) are present in PVAT and their effects in the vascular tone can be seen using phenylephrine (PHE), a selective ?1-AR agonist, and noradrenaline (NE), that acts at ?-AR and ?-AR, putting these agonists as keys to understand modulation of the vascular tone through PVAT – and for its dysfunction as well. The aim of the present study was to evaluate the AE of PVAT of the thoracic aorta of DOCA-salt animals when stimulated with PHE or NE. Methods: Uninefrectomized male Wistar rats (ICB-USP Animal Experimentation Ethics Committee, record nº 03/2016) were divided into SHAM and DOCA-salt groups. For 8 weeks, caudal blood pressure (BP) was accompanied by tail plethysmography. Afterwards, the rats were killed and aortic rings with (PVAT+) and without (PVAT-) PVAT were mounted on a wire myograph to analyze the vascular response to PHE or NE. Statistical analysis: t-test or ANOVA. Results: BP was 65% higher in DOCA-salt compared to SHAM. Contractile response to PHE or NE was reduced in aortic PVAT+ rings compared with PVAT- in both groups. In addition, the PVAT+ rings of DOCA-salt showed a loss of AE in response to PHE when compared to SHAM (-56% vs. SHAM). However, with NE this behavior was not observed, and there was no difference between responses of SHAM and DOCA-salt’s PVAT against this agonist. Conclusion: PVAT’s dysfunction found in DOCA-salt animals is not observed when stimulation is performed with a nonselective a- and b-AR agonist, demonstrating a protective effect, probably by b-AR, that prevents the loss of the PVAT AE in this condition.

   

• Palavras-chave
• PVAT, Adrenoceptor, Hypertension.
• Modalidade
• Pôster
• Área Temática
• Tecido adiposo perivascular