Article Text

PDF
181 Elucidating The Role Of β3-receptors In Perivascular Adipose Tissue
  1. Sophie Saxton,
  2. Charlotte Bussey,
  3. Sarah Withers,
  4. Gillian Edwards,
  5. Anthony Heagerty
  1. University of Manchester

Abstract

Introduction Perivascular adipose tissue (PVAT) has been shown by various studies to have an anti-contractile effect on the arteries it surrounds. The mechanism by which PVAT exerts its anti-contractile effect is not well understood, and is likely to involve the release of PVAT-derived relaxing factors (PVRF) such as adiponectin, that causes hyperpolarisation and relaxation of the vascular smooth muscle. The PVAT anti-contractile effect is lost in obesity, therefore understanding this mechanism is vital for creating novel treatments of obesity-related hypertension. We propose that the mechanism involves stimulation of adipocyte β3-adrenoceptors in PVAT.

Methods The contractile responses of noradrenaline and serotonin were assessed in rat mesenteric small arteries using wire myography with and without PVAT, and the effects of β3-agonist CL-316,243 (10µM), β3-antagonist SR59230A (1 µM), and adiponectin type-1 receptor blocking peptide were studied (2.5µM).

Results PVAT was shown to have a significant anti-contractile effect on the responses to both noradrenaline (n = 5, P = 0.0135) and serotonin (n = 5, P = 0.0096). The CL-316,243 was found to have no significant effect on either the concentration-response to noradrenaline (n = 6, P = 0.5584) or serotonin (n = 4, P = 0.2072). SR59230A induced a significant reduction in the anti-contractility of PVAT in vessels stimulated with the highest concentration of noradrenaline (n = 3, P = 0.0018), but not serotonin (n = 3, P = 00.0621). Adiponectin receptor type-1 blocking peptide has been shown to abolish the noradrenaline-induced anti-contractile effect; however in this study the blocking peptide had no significant effect on the serotonin-induced PVAT anti-contractility (n = 4, P = 0.505).

Conclusions and Implications These results suggest that β3-adrenoceptors may be involved in noradrenaline PVAT anti-contractility, but the serotonin-induced anti-contractile effect appears to be independent of events at β3-adrenoceptors, and involves a different PVRF.

  • PVAT
  • β3-adrenoceptors
  • obesity

Statistics from Altmetric.com

Request permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.