Related Experiment Video

Updated: Sep 26, 2026

Receptor Autoradiography Protocol for the Localized Visualization of Angiotensin II Receptors
12:03

Receptor Autoradiography Protocol for the Localized Visualization of Angiotensin II Receptors

Published on: June 7, 2016

AT1-receptor antagonism improves endothelial function in coronary artery disease by a

Burkhard Hornig1, Christoph Kohler, Daniel Schlink

  • 1Abteilung Kardiologie und Angiologie, Medizinische Hochschule Hannover, Carl Neuberg Str 1, 30625 Hannover, Germany. Hornig.Burkhard@mh-hannover.de

Hypertension (Dallas, Tex. : 1979)
|March 26, 2003
PubMed

Insights

Angiotensin type-1 receptor antagonists like candesartan improve blood vessel dilation in coronary artery disease (CAD) patients. This improvement involves both bradykinin and nitric oxide (NO) pathways.

Area of Science:

  • Cardiovascular Medicine
  • Pharmacology

Background:

  • Impaired flow-dependent, endothelium-mediated vasodilation is an early indicator of coronary artery disease (CAD).
  • Angiotensin type-1 receptor antagonists (AT1A) have shown potential in enhancing endothelium-dependent relaxation in CAD patients.

Purpose of the Study:

  • To investigate whether AT1A improves flow-dependent dilation (FDD) in patients with CAD.
  • To determine the involvement of bradykinin and nitric oxide (NO) in the vascular effects of AT1A in CAD.

Main Methods:

  • High-resolution ultrasound was used to measure radial artery diameter changes during reactive hyperemia.
  • Twenty CAD patients received intrabrachial infusions of candesartan, with or without icatibant (bradykinin B2-receptor antagonist) or N-monomethyl-l-arginine (NO-synthase inhibitor).

Main Results:

  • Candesartan significantly improved FDD by over 40% in CAD patients.
  • The beneficial effect of candesartan on FDD was significantly inhibited by both icatibant and L-NMMA.
  • Specific percentage changes in FDD were observed with candesartan alone and in combination with inhibitors.

Conclusions:

  • AT1A, exemplified by candesartan, effectively enhances flow-dependent, endothelium-mediated vasodilation in patients with CAD.
  • Both bradykinin and NO pathways play a crucial role in mediating the vascular benefits of AT1A in this patient population.

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