We next examined the hypothesis that ICV injection of FGF19 would improve plasma glucose concentrations in a severely hyperglycemic, insulinopenic rat model of T1D and found that plasma glucose, NEFA and glycerol concentrations were reduced markedly within 6 h following injection of 30 μg ICV FGF19 (Fig. 2a–c). Here, FGF19 is linked to type 1 diabetes mellitus.