Effect of the regulation of adiponectin on the expression of nitric oxide synthase in the retinas of diabetic rats / 中华实验眼科杂志

ABSTRACT

Background Diabetic retinopathy (DR) is a common complication of diabetic mellitus,but its pathogenesis is still unclear.Adiponectin may restrain inflammatory reaction and reduce adhesion of vascular endothelial cell to influence diabetic microangiopathy.Relation between adiponectin and nitric oxide synthase (NOS)is less reported.Objective This study was to observe the effect of adiponectin on the expression of NOS in the retinas of diabetic rats.Methods Forty 8-10 weeks Sprague-Dawley (SD) female rats were collected.The rats were randomized into the normal control group (10 rats),adiponectin group (15 rats) and diabetic model control group (15 rats) using the random number table method.Tetraoxypyrimidine was intraperitoneally injected to establish the diabetic model in the rats of the adiponectin group and diabetic model control group,and 10 μg/kg of adiponectin was then injected into the rats of the adiponectin group.Western blot was used to detect the expression of the adiponectin protein in the rat retinas,and the expression of NOS in rat retina was located by immunochemistry.The use of the animals complied with the Regulations for the Administration of Affairs Concerning Experimental Animals by State Science and Technology Commission.Results The relative amount of adiponectin (adiponectin/β-actin)in the retinas was 0.85 ± 0.21,0.79 ± 0.17 and 0.42 ± 0.08,respectively,in the normal control group,adiponectin group and diabetic model control group,with significant differences among the 3 groups (F =4.236,P =0.000).The adiponectin/β-actin ratio in the retinas of the diabetic model control group was significantly declined in comparison with the normal control group and adiponectin group (q =6.615,P =0.000 ; q =6.026,P =0.000).The NOS levels (A value) in the retinas were 0.244 ± 0.035,0.262 ± 0.032 and 0.367 ± 0.066,respectively,in the normal control group,adiponectin group and diabetic model control group,showing a significant difference among them (F =3.752,P =0.001).The A value of NOS in the diabetic model control group was significantly increased in comparison with the normal control group and adiponectin group (q =3.488,P =0.002 ; q =3.079,P =0.005).NOS expression was localized to the inner nuclear layer and retinal ganglion cell layer.Conclusions Adiponectin reduces NO content in diabetic rat retinas by regulating NOS expression.