Alteration of the trafficking of the insulin-sensitive GLUTs in the diabetic atria.

Decreased atrial A) GLUT4 and B) GLUT8 content during type 1 diabetes (T1Dx). Top panels: representative Western blot from crude membrane extract of perfused mouse atria, calsequestrin (CLSQ) was used as a loading control. Bottom panels: Mean ± SE of GLUT protein content (values expressed relative to control; n = 7-8/group). Type 1 diabetes decreased C) GLUT4 and D) GLUT8 trafficking to the atrial cell surface. Top panels: representative Western blot. Bottom panels: Mean ± SE of cell surface GLUT protein content (values expressed relative to control; n = 4-5/group). Majority of E) GLUT4 and F) GLUT8 is intracellular under basal conditions (mean ± SE, values expressed relative to control labeled, n = 5/group). Methods: Intact perfused mouse hearts were photolabeled with bio-LC-ATB-BGPA to determine the amount of cell surface (L: labeled fraction) and intracellular (UL: unlabeled fraction) content. T1Dx: type 1 diabetic; Con: control; * P<0.05 vs. control.