Islet structure and size, β-cell mass, and α-cell mass at twenty weeks of age.

<p>A. Representative islets from B6 (left) and WSB (right) mice fed the chow diet. Insulin is stained red, glucagon green, and cell nuclei are marked by DAPI staining (blue). No alteration to islet structures was found in islets from the high fat-fed mice. B. The average cross-sectional areas of all islets found in each mouse were determined then averaged for each strain (average number of islets per mouse examined: B6 chow- 167, B6 HFD 187, WSB chow 129, WSB HFD 171). C. Distribution of islet sizes in B6 (black; chow-fed solid, high fat diet (HFD)-fed striped) and WSB mice (white; chow-fed solid, high fat diet (HFD)-fed striped). In the upper group, although there was substantial overlap in the sizes, B6 mice tended to have larger maximal islet sizes (both diets). D. Percent of pancreatic tissue area stained for insulin. E. Pancreatic weight of mice used in these experiments. F. Pancreatic weights normalized to total body weight in chow and high fat-fed WSB and B6 mice. G. β-cell mass, calculated as the % staining area multiplied by the pancreatic weight. H. Percent of pancreatic area stained for glucagon. I. α-cell mass calculated as for β-cell mass. (n = 5 mice per strain per diet). *p<0.05, **p<0.01, ***p<0.001 vs. B6 mice consuming the same diet. +p<0.05, +++p<0.001 vs. chow-fed of the same strain.