D1 receptor expression and function in lean Zucker rats with hyperinsulinemia or hyperglycemia. Lean Zucker rats were fed high-fat diet (HFD) to induce hyperinsulinemia or intraperitoneally injected with streptomycin (STZ) to induce hyperglycemia. The mesenteric arteries preconstricted with PHE from those rats were treated with varying concentrations of fenoldopam (Fen, 10-9-10-5M) (A and B) (*P < 0.05, vs. lean Zucker rats, n = 8). D1 receptor expression was determined by immunoblotting (C) and D1 receptor phosphorylation (D) was determined by co-immunoprecipitation and immunobloting. D1 receptor serine phosphorylation was normalized by D1 receptor protein (*P < 0.05, vs. obese rats, n = 6).
Fu et al. Cardiovascular Diabetology 2014 13:50 doi:10.1186/1475-2840-13-50