Figure 4. In vivo metabolic studies with mice lacking barr2 in pancreatic β-cells.

(a–c) In vivo metabolic tests carried out with β-barr2-KO mice and control littermates maintained on RC. (a) Glucose-induced insulin secretion (GSIS; 2 g glucose per kg i.p.). (b) IGTT (2 g glucose per kg i.p.). (d) ITT (0.75 U insulin per kg i.p.). (d–f) β-barr2-KO mice and control littermates were maintained on a high-HFD and subjected to the same tests as in a–c. In d and e, the glucose dose was reduced to 1 g kg⁻¹ (i.p.). In (f), the insulin dose was 1 U kg⁻¹ (i.p.). Mice were maintained on the HFD for at least 8 weeks. All studies were carried out with male mice (mouse age: RC, 10–16 weeks; HFD, 16–22 weeks). Data are given as means±s.e.m. (8–12 mice per group). *P<0.05, **P<0.01, as compared with the corresponding control value (Student's t-test).