Reactive oxygen species as mediators of angiotensin II signaling.

Angiotensin II stimulates a plethora of signaling pathways leading to cell growth and contraction. Recent work has shown that reactive oxygen species are involved in transducing many of the effects of angiotensin II, and are in fact produced in response to agonist-receptor binding. Angiotensin II stimulates a NAD(P)H oxidase to produce superoxide and hydrogen peroxide, both of which may act on intracellular growth-related proteins and enzymes to mediate the final physiological response. Of particular importance is hydrogen peroxide, which mediates angiotensin II stimulation of such important intracellular signals as EGF-receptor transactivation, p38 mitogen activated protein kinase, and Akt. Future work will be directed towards identifying other important redox-sensitive signaling pathways and their relationship to the physiology and pathophysiology of the renin-angiotensin system.