Figure 2. Beta cell proliferation in islets from nondiabetic rats (dotted columns), type 2 diabetic rats (hatched columns) and type 1 diabetic rats (black columns) treated with saline or CCK-8 (1, 2 and 4 μg/kg). Pancreata slices were immunostained for PCNA and insulin. After counterstaining, at least 2000 nuclei in non-diabetic rats and type 2 diabetic rats or 1000 nuclei in type 1 diabetic rats were counted per pancreas. The data (mean±SEM) are represented as percentages of PCNA labeled beta cells to the total number of insulin labeled beta cells. **P< 0.001; comparisons between CCK-8 treated (n=6) and saline treated (n=6) rats