INS and diabetes mellitus: The islet insulin+ areas in these rats were 30- and 21-fold larger than in the control (saline- and His42-treated) and 17D5 delayed diabetes rats, respectively, and the insulin+ cells represented 76 ± 3% of all islet cells (Figures 2I–K), which is comparable to that in the normoglycemic DRLyp/Lyp rats at 40 days of age (P > 0.05).