Myocardial interstitial collagen expression and capillary density in control and diabetic rats. Interstitial collagen accumulation (C) assessed via picrosirius red staining in control (A) and diabetic (B) rats (20× objective). Capillary density (F) assessed via isolectin B4 staining in control (D) and diabetic (E) rats (40× objective). There was no significant difference between groups. Control, n = 6 and diabetic, n = 8. Values expressed as mean ± SEM.