SLC2A4 and Huntington disease: Despite similar AMPK activation levels in skeletal muscle between WT controls (WT; Scn4a+/+) and HD transgenic mice (HD; Scn4a+/+), the levels of the AMPK-controlled glucose transporter GLUT-4 were downregulated in skeletal muscle in HD mice when compared to non-transgenic controls (Fig. 2B), providing a potential explanation for the higher free-fed glucose levels in serum of HD mice (Fig. 2C).