In this study we measured the cell surface IRAP activity and 3-O-[methyl-14C]-D-Glucose uptake in adipocytes isolated from Otsuka Long Evans Tokushima Fatty rats (OLETF), developed as a model of type 2 diabetes mellitus, to evaluate whether the translocation of GLUT4/IRAP vesicles is affected.     ///    Continuous measurement of cell surface IRAP activity allowed accurate evaluations of GLUT4/IRAP vesicle translocation and of the establishment of defects in OLETF rats.. 