TABLE 3

Pancreatic β-cell area, islet infiltration, and immune cell composition in IDDM rats in the time course of diabetes development

Age (days)NPancreatic β-cell area
Infiltrated pancreatic islet area
Immune cell subpopulations in the infiltrated pancreatic islets
Total immune cells
ED1-macrophages
CD 4+ T-cells
CD 8+ T-cells
NK-cells
B-cells
mm2%mm2%cells/mm2%cells/mm2%cells/mm2%cells/mm2%cells/mm2%cells/mm2%
5017.84412.7682781008731197163595241
5565.8 ± 0.4*3520.7 ± 0.3111345 ± 2110092 ± 122733 ± 510201 ± 175814 ± 345 ± 11
5933.8 ± 0.2*2310.7 ± 0.458307 ± 1310073 ± 92432 ± 310178 ± 205817 ± 267 ± 12
60122.3 ± 0.3147.8 ± 0.342280 ± 1210067 ± 102427 ± 410169 ± 136012 ± 345 ± 12
80000000000000000
  • Data are means ± SE. Pancreatic β-cell area was determined by morphometric analysis of pancreatic sections stained for insulin. The infiltrated islet area and the total number of infiltrated immune cells of different subpopulations per islet area were determined by morphometric analysis of hematoxylin and eosin–stained pancreatic sections and specific immunostaining from animals of 50, 55, 59, 60, and 65 days of age, compared with the control situation in noninfiltrated pancreas at day 45. The β-cell area of islets in the control animals was 16.6 ± 0.2 mm2, and the total islet area of these noninfiltrated islets represented 18.6 ± 0.2 mm2. Both values were set as 100% in comparison with the β-cell area and the total islet area including infiltration in diabetic animals. A total of 15 islets from three different regions of the pancreas were examined per animal. The number of animals at each time point is given in Table 1. The number of immune cells of the infiltrate are presented as cells per squared millimeters of islet area and in addition as a percentage of the total immune cell infiltrate at each time point.

  • *

    * P ≤ 0.05 compared with day 45

  • P ≤ 0.01 compared with day 45

  • P ≤ 0.05 compared with day 50 (all by ANOVA/Dunnett test).