Increased Circulating Angiotensin‐(1‐7) in Transgenic Rats Modulates Lipogenic and Lipolytic Activities in Adipose Tissue

Abstract

We evaluated the lipid metabolism in the adipose tissue of transgenic rats that overexpress an Angiotensin (Ang)‐(1‐7)‐producing fusion protein, TGR(A1‐7)3292 (TGR), which induces a lifetime increase in circulating levels of this peptide. Male Sprague‐Dawley rats, control (C) and TGR, 12‐15 weeks old, were used. After removal of epididymal, mesenteric and retroperitoneal adipose tissues, adiposity index was calculated. Lipogenic and lipoprotein lipase (LPL) activities were evaluated in epididymal adipose tissue and triacylglycerol (TAG) hydrolases activity were analyzed in retroperitoneal adipose tissue. Data are means±SEM (p<0.05). The results obtained in fed rats showed reduction of 35% in visceral adiposity in the TGR group in relation to control. Basal lipogenesis presented reduction in the TGR group when compared to control (TGR:124±14; C:279±36). Insulin‐stimulated lipogenesis was also reduced in the TGR group in relation to control (TGR:229±35; C:414±21). The TGR animals presented decreased LPL activity compared to control (TGR:0.70±0.14; C:1.56±0.18). TAG hydrolases activity was increased in the TGR group in relation to control (TGR:0.79±0.05; C:1.01±0.05). Our data show that increased levels of Ang‐(1‐7) have beneficial effects on the reduction of visceral adiposity, probably by decreasing fatty acids uptake and lipogenic activity in epididymal adipose tissue and by increasing TAG‐hydrolytic activity in retroperitoneal adipose tissue.Supported by: CNPq, CAPES, FAPEMIG