High salt diet modulates vascular response in A2AAR (+/+) and A 2AAR (-/-) mice: role of sEH, PPARγ, and K ATP channels

Mol Cell Biochem. 2015 Jun;404(1-2):87-96. doi: 10.1007/s11010-015-2368-4. Epub 2015 Mar 5.

Abstract

This study aims to investigate the signaling mechanism involved in HS-induced modulation of adenosine-mediated vascular tone in the presence or absence of adenosine A2A receptor (A2AAR). We hypothesized that HS-induced enhanced vascular relaxation through A2AAR and epoxyeicosatrienoic acid (EETs) is dependent on peroxisome proliferator-activated receptor gamma (PPARγ) and ATP-sensitive potassium channels (KATP channels) in A2AAR(+/+) mice, while HS-induced vascular contraction to adenosine is dependent on soluble epoxide hydrolase (sEH) that degrades EETs in A2AAR(-/-) mice. Organ bath and Western blot techniques were conducted in HS (4 % NaCl) and normal salt (NS, 0.45 % NaCl)-fed A2AAR(+/+) and A2AAR(-/-) mouse aorta. We found that enhanced vasodilation to A2AAR agonist, CGS 21680, in HS-fed A2AAR(+/+) mice was blocked by PPARγ antagonist (T0070907) and KATP channel blocker (Glibenclamide). Also, sEH inhibitor (AUDA)-dependent vascular relaxation was mitigated by PPARγ antagonist. PPARγ agonist (Rosiglitazone)-induced relaxation in HS-A2AAR(+/+) mice was attenuated by KATP channel blocker. Conversely, HS-induced contraction in A2AAR(-/-) mice was attenuated by sEH inhibitor. Overall, findings from this study that implicates the contribution of EETs, PPARγ and KATP channels downstream of A2AAR to mediate enhanced vascular relaxation in response to HS diet while, role of sEH in mediating vascular contraction in HS-fed A2AAR(-/-) mice.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Aorta / drug effects
  • Aorta / physiology*
  • Arachidonic Acids / metabolism
  • Benzamides / administration & dosage
  • Enzyme Inhibitors / administration & dosage
  • Epoxide Hydrolases / metabolism*
  • KATP Channels / genetics
  • KATP Channels / metabolism*
  • Mice
  • PPAR gamma / genetics
  • PPAR gamma / metabolism*
  • Pyridines / administration & dosage
  • Receptor, Adenosine A2A / genetics*
  • Receptor, Adenosine A2A / metabolism
  • Sodium Chloride / administration & dosage
  • Vasodilation / drug effects

Substances

  • Arachidonic Acids
  • Benzamides
  • Enzyme Inhibitors
  • KATP Channels
  • PPAR gamma
  • Pyridines
  • Receptor, Adenosine A2A
  • T 0070907
  • Sodium Chloride
  • Epoxide Hydrolases