GLP-1 receptor activation and Epac2 link atrial natriuretic peptide secretion to control of blood pressure

Nat Med. 2013 May;19(5):567-75. doi: 10.1038/nm.3128. Epub 2013 Mar 31.

Abstract

Glucagon-like peptide-1 receptor (GLP-1R) agonists exert antihypertensive actions through incompletely understood mechanisms. Here we demonstrate that cardiac Glp1r expression is localized to cardiac atria and that GLP-1R activation promotes the secretion of atrial natriuretic peptide (ANP) and a reduction of blood pressure. Consistent with an indirect ANP-dependent mechanism for the antihypertensive effects of GLP-1R activation, the GLP-1R agonist liraglutide did not directly increase the amount of cyclic GMP (cGMP) or relax preconstricted aortic rings; however, conditioned medium from liraglutide-treated hearts relaxed aortic rings in an endothelium-independent, GLP-1R-dependent manner. Liraglutide did not induce ANP secretion, vasorelaxation or lower blood pressure in Glp1r(-/-) or Nppa(-/-) mice. Cardiomyocyte GLP-1R activation promoted the translocation of the Rap guanine nucleotide exchange factor Epac2 (also known as Rapgef4) to the membrane, whereas Epac2 deficiency eliminated GLP-1R-dependent stimulation of ANP secretion. Plasma ANP concentrations were increased after refeeding in wild-type but not Glp1r(-/-) mice, and liraglutide increased urine sodium excretion in wild-type but not Nppa(-/-) mice. These findings define a gut-heart GLP-1R-dependent and ANP-dependent axis that regulates blood pressure.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Aorta / metabolism
  • Aorta / pathology
  • Atrial Natriuretic Factor / metabolism*
  • Blood Pressure*
  • Cyclic GMP / metabolism
  • Diabetes Mellitus, Type 2 / drug therapy
  • Endothelium, Vascular / metabolism
  • Gene Expression Regulation*
  • Glucagon-Like Peptide 1 / analogs & derivatives
  • Glucagon-Like Peptide 1 / pharmacology
  • Glucagon-Like Peptide-1 Receptor
  • Guanine Nucleotide Exchange Factors / metabolism*
  • Liraglutide
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Natriuretic Peptide, C-Type / genetics
  • Perfusion
  • Protein Precursors / genetics
  • Receptors, Glucagon / metabolism*
  • Vasodilation

Substances

  • Glp1r protein, mouse
  • Glucagon-Like Peptide-1 Receptor
  • Guanine Nucleotide Exchange Factors
  • Nppa protein, mouse
  • Protein Precursors
  • Rapgef4 protein, mouse
  • Receptors, Glucagon
  • Natriuretic Peptide, C-Type
  • Liraglutide
  • Atrial Natriuretic Factor
  • Glucagon-Like Peptide 1
  • Cyclic GMP