Angiotensin II Stimulates Intercellular Adhesion Molecule-1 (ICAM-1) Expression by Human Vascular Endothelial Cells and Increases Soluble ICAM-1 Release In Vivo

Background—We evaluated whether angiotensin II (Ang II) influenced intercellular adhesion molecule (ICAM)-1 expression by human vascular endothelial cells derived from umbilical cord veins (HUVECs) and plasma soluble ICAM-1 levels in vivo. Methods and Results—Cultured HUVECs were incubated with Ang II (from 10−9 to 10−6 mol/L) with or without candesartan and PD12319 (inhibitors of Ang II AT1 and AT2 receptors, respectively) for various times up to 4 hours. Total RNA was then extracted from HUVECs, and Northern blots were probed with a 1.9-kb ICAM-1 cDNA fragment. HUVEC supernatants were used to assess soluble ICAM-1 release by ELISA. Northern blot analysis detected a strong increase of ICAM-1 mRNA after 2-hour incubation with Ang II. The response was inhibited by candesartan. Soluble ICAM-1 release by HUVECs also increased (P<0.002) after 2-hour Ang II stimulation. In vivo, Ang II (at an initial rate of 1.0 ng · kg−1 · min−1, to be increased each 30 minutes by 2.0 ng · kg−1 · min−1 to the final rate of 7....