Angiotensin II: A hormone that affects lipid metabolism in adipose tissue

Abstract

Background: Alterations in adipose tissue lipolysis may contribute to the pathophysiology of obesity and insulin resistance. We examined the effects of angiotensin II (Ang II) on abdominal subcutaneous adipose tissue lipolysis in humans. Methods and results: First, adipocytes obtained from nine normal weight and seven obese subjects were stimulated with Ang II (10-14-10 -6 M). Glycerol concentration in the medium, used as an indicator of adipocyte lipolysis, was significantly reduced (∼20%) after Ang II stimulation in adipocytes from normal weight (P=0.04) and obese subjects (P<0.001). Based on these observations, adipocytes of seven additional obese subjects were stimulated with lower doses of Ang II (10-17-10 -6 M) in the presence and absence of Ang II type 1 (AT1) receptor blockade. Lipolysis was dose dependently inhibited by ∼20 to 25% after Ang II stimulation (P=0.001). AT1 receptor blockade completely abolished the Ang II-induced effects (P=0.35). Conclusion: Ang II directly inhibits abdominal subcutaneous adipocyte lipolysis in normal weight and obese subjects via the AT1 receptor. © 2007 Nature Publishing Group All rights reserved.