Figure 3

Co-localization of red GLP-1R, green GLP-1 and blue Rab7 in islets of non-diabetic and diabetic rats. CLM images in a (a) 25-week-old non-diabetic Wistar rat (BW 489 g, FBS 119 mg/dl) and (b) 25-week-old diabetic GK rat (BW 450 g, FBS 249 mg/dl) were taken at 20× magnification. The yellow arrow in Fig. 2a indicates a small red dot in non-alpha cells. The CLM image in the white rectangular area in Fig. 3b was taken at 63× magnification and split into red GLP-1R (c), green GLP-1 (d) and blue Rab7 (e). Figure 3f is a merged image of Fig. 3c–e. Figure 3g is a differential interference contrast (DIC) microscopy image that was taken simultaneously. Figure 3h is a merged image of Fig. 3f and g. The yellow and orange arrows in Fig. 3c–h indicate large and small endosomes, respectively. The green arrows in Fig. 3c–h indicate one of the small endosomes. The white arrows in Fig. 3d indicate cytoplasmic GLP-1-positive alpha cells.