MAS‐Knockout Mice Produces Altered Metabolic Responses in Adipocytes

Abstract

This study investigated the adipocyte metabolism in wild type (WT) and FVB/N Mas‐deficient male mice (KO). Plasma triglyceride (TG) and free fatty acid (FFA) were assayed by enzymatic methods. Epididymal adipocytes were incubated in the presence or absence of isoproterenol and the effects of insulin on isoproterenol‐stimulated lipolysis were determined. Quantification of hormone‐sensitive lipase (HSL) protein was measured by Western blotting. Epididymal adipocytes were incubated in the presence or absence of insulin and uptake of 2‐deoxy‐[3H] glucose was estimated. Gene expression of PPARγ was measured by real time RT‐PCR. KO mice showed greater levels of plasma TG and FFA compared to WT mice (p<0.05). The lipolitic activity as basal as induced by isoproterenol was the same in both groups. The insulin decreased 41% the lipolitic activities stimulated by isoproterenol in a WT group (p<0.05), while no effect of the insulin action was observed in KO group. The amount of HSL enzyme was similar in WT and KO groups. The glucose uptake in the basal condition was the same in both groups. However, adipocytes of KO group showed a decreasing of 39% of glucose uptake stimulated by insulin compared to adipocytes of WT group (p<0.05). The expression of PPARγ is reduced in 66% in KO animals (p<0.05). Our data suggested that the lack of Ang‐(1‐7) action through Mas receptor alters the response of adipocytes of insulin action.