Representative pancreas immunochemistry in 4-month-old male Wistar (A–G) and GK (H–N) rats.

<p>Serial staining (brown) for: (A, H) insulin (β-cell marker), (B, I) glucagon+somatostatin+pancreatic polypeptide cocktail (non-β cell marker), (C, J) α-amylase (acinar cell marker), and (D, K, and F–G, M–N) REG-1. For REG-1 labeling, we used the monoclonal anti-rat REG-1 antibody from Hiroshi Okamoto (Japan). REG-1 negative controls are shown in (E, L). In (F–G) and (M–N), the border of islets is defined by the red dashed line. In Fig. 2N, “d” means “duct”.