Figure 5: β-cell insulin content. Representative pictures of insulin staining (red) with hematoxylin counterstain from all the four groups. A) Sedentary control rat islets contained clear insulin staining. B) Diabetic rat islets contained dramatically less insulin and at times, islets were difficult to identify due to the poor insulin staining. C) Exercised lean rats contained islets brightly-stained for insulin. D) Exercise appeared to improve the insulin intensity in the diabetic rat islets. E) Quantification of the images showed that exercise significantly reduced the insulin staining in the lean controls, and significantly increase insulin staining in the diabetic rats. Further the sedentary diabetic rat islet insulin staining was significantly less than the sedentary non-diabetic rats. In fact, the only comparison that was not statistically different was between the lean exercised animals and the sedentary diabetic rats. Scale bar represents 100 µm.