Additional studies. Tripsin digestive technique of the retina (A, B). A, LT-DBT capillary-net, arrows point to acellular capilary. B: vascular capillary-net from a retina between middle size vessels. Arrow points to pericytes and arrowhead to endothelial cells. C, Number of pericytes per capillary area was determined as indicated in methods section. Results are mean ± SEM of five rats in each group. *P <0.05. D, E and F are transverse retinal sections with GFAP immunostaining from LT-DBT rats (D), ST-DBT rats (E) and controls (F). Diabetic retinas (D and E) overexpressed GFAP in the fibre layer and in cells with the morphology and spatial organisation of Müller cells. Bar 50 μm.