In vivo stimulation of perivascular adipose tissue exerts a local anti-constrictive effect on arteries, mediated via adipocyte β3-adrenoceptors and the release of adiponectin.
Does perivascular adipose tissue modulate local vascular tone in vivo in rats?
Perivascular adipose tissue plays a paracrine role in regulating local vascular tone in vivo via adipocyte β3-adrenoceptors and adiponectin, potentially contributing to blood pressure modulation.
BACKGROUND: 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 β3-adrenoceptors play a role in PVAT function via secretion of the vasodilator adiponectin. OBJECTIVE: We have investigated the effects of PVAT on vessel diameter in vivo, and the contributions of β3-adrenoceptors and adiponectin. METHOD: 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). RESULTS: 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 β3-adrenoceptor inhibition, and activation of β3-adrenoceptors potentiated the anti-constrictive effect of vessels stimulated with EFS, NA, and AVP. The β3-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 β3-adrenoceptor activation. CONCLUSIONS: 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 β3-adrenoceptors, which may trigger release of the vasodilator adiponectin.
Saxton et al. (Tue,) conducted a other in Vascular tone regulation. Perivascular adipose tissue (PVAT) stimulation vs. Arteries with PVAT removed was evaluated on Vessel diameter in vivo. In vivo stimulation of perivascular adipose tissue exerts a local anti-constrictive effect on arteries, mediated via adipocyte β3-adrenoceptors and the release of adiponectin.