Role of NADPH Oxidase in the Vascular Hypertrophic and Oxidative Stress Response to Angiotensin II in Mice

Abstract

—Oxygen-derived free radicals are involved in the vascular response to angiotensin II (Ang II), but the role of NADPH oxidase, its subunit proteins, and their vascular localization remain controversial. Our purpose was to address the role of NADPH oxidase in the blood pressure (BP), aortic hypertrophic, and oxidant responses to Ang II by taking advantage of knockout (KO) mice that are genetically deficient in gp91phox, an NADPH oxidase subunit protein. The baseline BP was significantly lower in KO mice than in wild-type (WT) (92±2 [KO] versus 101±1 [WT] mm Hg, P0.4). Ang II increased aortic superoxide anion production 2-fold in the aorta of WT mice but did not do so in KO mice. Aortic medial area increased in WT (0.12±0.02 to 0.17±0.02 mm2, P0.05). Histochemistry and polymerase chain reaction demonstrated ...