TABLE 1

Characteristics of IDDM rats during diabetes development

Age (days)NNormoglycemic rats without pancreas infiltration
Normoglycemic rats with pancreas infiltration
Diabetic rats
n (%)Blood glucose (mmol/l)Serum insulin (ng/ml)n (%)Blood glucose (mmol/l)Serum insulin (ng/ml)Insulitis Scoren (%)Blood glucose (mmol/l)Serum insulin (ng/ml)Insulitis Score
451111 (100)4.7 ± 0.21.3 ± 0.20 (0)0 (0)
502015 (75)4.9 ± 0.21.2 ± 0.24 (20)5.1 ± 0.21.2 ± 0.21.1 ± 0.11 (5)10.90.81.9
554333 (77)4.5 ± 0.11.2 ± 0.24 (9)5.0 ± 0.11.2 ± 0.22.0 ± 0.16 (14)13.0 ± 0.20.7 ± 0.12.5 ± 0.1
59147 (50)4.7 ± 0.11.0 ± 0.24 (29)5.3 ± 0.21.0 ± 0.12.4 ± 0.23 (21)17.1 ± 0.1*0.4 ± 0.23.3 ± 0.2
60208 (40)4.6 ± 0.11.0 ± 0.20 (0)12 (60)19.5 ± 0.1*0.10 ± 0.05*3.3 ± 0.2
65124 (33)4.8 ± 0.21.0 ± 0.10 (0)8 (67)22.7 ± 0.3*0.05 ± 0.01*4.0 ± 0.1
  • Data are means ± SE. Rats were classified as diabetic when blood glucose concentration was >7.5 mmol/l at the respective time point. Pancreas infiltration and insulitis scores were determined by morphological analyses of pancreatic sections. Islet infiltration was graded on a score of 0–4 as follows: stage 0, no immune cell infiltration of the islets (control); stage 1, immune cell infiltration restricted to the islet periphery; stage 2, faint invasive immune cell islet infiltration; stage 3, complete islet infiltration with large numbers of immune cells; and stage 4, complete β-cell loss without any immune cell infiltration (end-stage islets). A mean insulitis score was calculated from 20 to 30 islets per individual pancreas.

  • *

    * P ≤ 0.05 compared with day 55 (ANOVA/Dunnett test).