Angiotensin II-dependent hypertension requires cyclooxygenase 1-derived prostaglandin E2 and EP1 receptor signaling in the subfornical organ of the brain Academic Article uri icon

Overview

MeSH Major

  • Angiotensin II
  • Cyclooxygenase 1
  • Dinoprostone
  • Hypertension
  • Receptors, Prostaglandin E, EP1 Subtype
  • Signal Transduction
  • Subfornical Organ

abstract

  • Cyclooxygenase (COX)-derived prostanoids have long been implicated in blood pressure (BP) regulation. Recently prostaglandin E(2) (PGE(2)) and its receptor EP(1) (EP(1)R) have emerged as key players in angiotensin II (Ang II)-dependent hypertension (HTN) and related end-organ damage. However, the enzymatic source of PGE(2,) that is, COX-1 or COX-2, and its site(s) of action are not known. The subfornical organ (SFO) is a key forebrain region that mediates systemic Ang II-dependent HTN via reactive oxygen species (ROS). We tested the hypothesis that cross-talk between PGE(2)/EP(1)R and ROS signaling in the SFO is required for Ang II HTN. Radiotelemetric assessment of blood pressure revealed that HTN induced by infusion of systemic "slow-pressor" doses of Ang II was abolished in mice with null mutations in EP(1)R or COX-1 but not COX-2. Slow-pressor Ang II-evoked HTN and ROS formation in the SFO were prevented when the EP(1)R antagonist SC-51089 was infused directly into brains of wild-type mice, and Ang-II-induced ROS production was blunted in cells dissociated from SFO of EP(1)R(-/-) and COX-1(-/-) but not COX-2(-/-) mice. In addition, slow-pressor Ang II infusion caused a ≈3-fold increase in PGE(2) levels in the SFO but not in other brain regions. Finally, genetic reconstitution of EP(1)R selectively in the SFO of EP(1)R-null mice was sufficient to rescue slow-pressor Ang II-elicited HTN and ROS formation in the SFO of this model. Thus, COX 1-derived PGE(2) signaling through EP(1)R in the SFO is required for the ROS-mediated HTN induced by systemic infusion of Ang II and suggests that EP(1)R in the SFO may provide a novel target for antihypertensive therapy.

publication date

  • April 2012

Research

keywords

  • Academic Article

Identity

Language

  • eng

PubMed Central ID

  • PMC3307140

Digital Object Identifier (DOI)

  • 10.1161/HYPERTENSIONAHA.111.182071

PubMed ID

  • 22371360

Additional Document Info

start page

  • 869

end page

  • 76

volume

  • 59

number

  • 4