Immunological Injuries On The Retina Of STZ-induced Diabetic Rats

Background and aims: Diabetic retinopathy (DR) is believed to be one of the commonest and the most severe complications in diabetic mellitus, the main factor leading to blindness. The pathological manifestations of diabetic retinopathy are the selective loss of pericytes, capillaries endothelial basement membrane thickening, increase in vasopermeability and retinal neovascularization. The abnormality of retinal microcirculation is a critical factor for diabetic retinopathy, and the relativelly selective loss of pericytes from the retinal capillaries is a characteristic lesion that occurs early in the histopathology of diabetic retinopathy. Based on orthodox theory, by the traditional understabding,the pathogenesis of DR is somehow related to the following factors: 1 the abnormal metabolism of polyol-Inositol; 2 free radical; 3 no-enzymatic glycation reaction of protein; 4 activation of DG-PKC system; 5 role of cytokine; 6 local rennin-angiotensin. Recently, it is by both skin and kidney biopsies on the T2DM patients with pretibial patches while a lots of immune complex (IgA, IgG, IgM, FRA, C1, C3, C1q) were detected in the glomcrulus, renal interstitium, renal tubule, Bowman's capsule and patches as well. It indicates that autoimmune process may be likely to be involved in the pathogenesis of diabetic nephropathy (DN). Because the DR and DN are believed to be of diabetic microangiopathy, it is reasonable for us to suggest that autoimmune processes must be involved in the pathogenesis of DR. Besides this, however, the depositions of immunoglobulin are found in DR, consistent with what we had thought. In the present study, the experimental model of diabetic rat was induced by intravenous administration of streptozotocin, the pathological abnormalities of diabetic rat retina was studied with the HE staining under a light microscope, the expression of immunoglobulinin the retina of diabetic rat was also studied with Immunohistochernical technique.The aim of our study was to confirm the effects of immunoglobulin in DRdevelopment.Furthermore the significance of our work remains to be an importantstep for a new regime for the prevention and treatment of DR.Materials and methods: Diabetic SD rats models were established byintravenous administration of streptozotocin (50 mg/kg body wt, dissolved incitrate buffer pH 4.2). The serum CRP of diabetic rat was determined withenzyme linked immunosorbent assay (ELISA). The expression ofimmunoglobulin in the retina of diabetic rat was studied withimmunohistochemistry and computer age-analysing instrument. SPSS was used toanalyze the data.Results: In comparison with control group, the expression of immunoglobulin onthe retina of diabetic rat was significantly increased (p<0.05).With the progress ofdiabetes, immunoglobulins were increased first and then were declinede gradually,but still significantly elevated in comparison with the control group (for each,p<0.05). There was no statistical significance for the difference in theexpression of immunoglobulin in the retina of diabetic rat between the differentperiods.Conclusion: The immunoglobulins were shown to be involved in thepathogenesis of DR.Part twoThe effects of tumor necrosis factor alpha in the development ofdiabetic retinopathyBackground and aims: Diabetic retinopathy(DR), the main factor leading to blindness, is believed to be one of the commonest and the most severe...