A preliminary study on the relationship between adhesion molecules and diabetic retinopathy in diabetic rats

Objective To explore the role of adhesion molecules in the development of diabetic retinopathy (DR) in diabetic rats. Methods Diabetes model was established in Wistar rats by induction with streptozotocin (STZ). The early changes of retinae were examined using light microscope and transmission electron microscope. Immunohistochemistry was employed to analyse the expression of ICAM 1 and CD61 (integrin β 3 chain) in diabetic retinae. Flow cytometric analysis was applied to detect the expression of CD11a (LFA 1 α chain) and CD11b (MAC 1 α chain) on the surface of neutrophils isolated from the systemic circulation. Results The early stages of ocular lesions occured in the retinae of diabetic rats at 3 months. The nondiabetic retinae demonstrated relatively little ICAM 1 immunoreactivity and CD61 immunoreactivity was rarely observed. While ICAM 1 and CD61 immunoreactivity was consistently greater than that observed in normal retinae (P0.01). The increased expression occurred before visible retinal pathological changes. A significant increase in number of neutrophils isolated from systemic circulation, which expressed CD11a/CD11b was found in the pathologic group as compared with the control group (P0.001). The thickness of capillary basement membrane was correlated positively with the immunoreactivities of ICAM 1 and CD61 in the retinae. Conclusion The results indicate that increased intercellular adhesion molecules may be the main inductive mediator and play an important role in the progression of diabetic retinal microangiopathy.