Abstract

Summary
Vascular infl ammation is involved in the initiation and progression of atherosclerosis, and is also present in hypertension- and diabetes-induced vascular complications. Angiotensin II (Ang II), the key effector of the renin-angiotensin system (RAS), plays a central role in the regulation of blood pressure and electrolyte homeostasis. There is accumulating evidence to indicate that Ang II is also capable of inducing infl ammatory response in the vascular wall. This review summarizes the current understanding of the molecular mechanisms and signal transduction pathways of Ang II-induced vascular infl ammation. The roles of modulators of Ang II-induced infl ammatory response, such as nitric oxide (NO), bradykinin,
cyclooxygenase-2 (COX-2), endothelin-1 (ET-1), and epoxyeicosatrienoic acids (EETs), are also discussed. The current data suggest that Ang II modifi es several steps of infl ammatory response, such as increase of vascular permeability, leukocyte infi ltration, tissue hypertrophy/proliferation, and fi brosis.
Ang II, via the type 1 (AT1) receptors, enhances the production of reactive oxygen species (ROS) through stimulation of NAD(P)H oxidase in the vascular wall. Increased oxidative stress contributes to
endothelial dysfunction and to vascular infl ammation by stimulating the redox-sensitive transcription factors (NF-kB) and by upregulating adhesion molecules, cytokines, and chemokines. The pro-infl ammatory action of Ang II may help us to understand the molecular mechanisms of hypertension- and diabetes- induced vascular complication as well as the pleiotropic actions of drugs interfering with RAS.

Keywords: Inflammation - physiopathology, Angiotensin II - physiology, Blood Vessels - physiopathology, Capillary Permeability, Cyclooxygenase 2, Endothelin-1 - physiology, Inflammation - physiopathology, Membrane Proteins, Nitric Oxide - physiology, Prostaglandin-Endoperoxide Synthases - metabolism