Perivascular Adipose Tissue Contributes to the Modulation of Vascular Tone in vivo

Abstract

<b><i>Background:</i></b> Perivascular adipose tissue (PVAT) reduces vascular tone in isolated arteries in vitro, however there are no studies of PVAT effects on vascular tone in vivo. In vitro adipocyte β<sub>3</sub>-adrenoceptors play a role in PVAT function via secretion of the vasodilator adiponectin. <b><i>Objective:</i></b> We have investigated the effects of PVAT on vessel diameter in vivo, and the contributions of β<sub>3</sub>-adrenoceptors and adiponectin. <b><i>Method:</i></b> In anaesthetised rats, sections of the intact mesenteric bed were visualised and the diameter of arteries was recorded. Arteries were stimulated with electrical field stimulation (EFS), noradrenaline (NA), arginine-vasopressin (AVP), and acetylcholine (Ach). <b><i>Results:</i></b> We report that in vivo, stimulation of PVAT with EFS, NA, and AVP evokes a local anti-constrictive effect on the artery, whilst PVAT exerts a pro-contractile effect on arteries subjected to Ach. The anti-constrictive effect of PVAT stimulated with EFS and NA was significantly reduced using β<sub>3</sub>-adrenoceptor inhibition, and activation of β<sub>3</sub>-adrenoceptors potentiated the anti-constrictive effect of vessels stimulated with EFS, NA, and AVP. The β<sub>3</sub>-adrenoceptor agonist had no effect on mesenteric arteries with PVAT removed. A blocking peptide for adiponectin receptor 1 polyclonal antibody reduced the PVAT anti-constrictive effect in arteries stimulated with EFS and NA, indicating that adiponectin may be the anti-constrictive factor released upon β<sub>3</sub>-adrenoceptor activation. <b><i>Conclusions:</i></b> These results clearly demonstrate that PVAT plays a paracrine role in regulating local vascular tone in vivo, and therefore may contribute to the modulation of blood pressure. This effect is mediated via adipocyte β<sub>3</sub>-adrenoceptors, which may trigger release of the vasodilator adiponectin.

Role of Perivascular Adipose Tissue-Derived Adiponectin in Vascular Homeostasis

“…The involvement of β3-adrenoreceptors in the regulation of adiponectin gene expression remains to be elucidated [83,85]. Further evidence of adiponectin-mediated vascular relaxation was provided by a recent study that confirmed previously reported results using an in vivo rat model [86].…”

Perivascular adipose tissue-derived nitric oxide compensates endothelial dysfunction in aged pre-atherosclerotic apolipoprotein E-deficient rats

“…Previously, it was reported that healthy PVAT confers atheroprotective effects by an increased secretion of adiponectin, which in turn promotes the phosphorylation of eNOS via AMPK and production of NO. [6,38,39] Unchanged mRNA adiponectin expression may have resulted from adaptive mechanisms that may have occurred during the 51 weeks of HFD and considering that in our study the age of rats at assessment was 59 weeks.…”

Exosomes facilitate intercellular communication between uterine perivascular adipose tissue and vascular smooth muscle cells in pregnant rats

“…Perivascular adipose tissue is a metabolically active adipose depot that secretes adipocytokines with paracrine actions on the adjacent vascular wall ( 5 , 29 – 31 ). A recent study by Li et al ( 15 ) demonstrated that mouse mesenteric PVAT secretes extracellular vesicles that carry their cargo into VSMCs.…”