The Influence Of Aspirin On The Expression Of Intercellular Adhesion Molecular-1(ICAM-1) In The Streptozocin(STZ)-induced Diabetes Mellitus(DM) Rats' Retina

Objective : Diabetes mellitus(DM) has become the public health problem that is concerned by many countries all over the world. Diabetic retinopathy(DR) is one of the most common and important diabetic microvascular complications,and has close relationship with other chronic diabetic complications. As DR usually predicts how serious the pathologic changes of the blood vessels and the nervous system are, it is important and significant to study the possible pathogenesis and the treatment of DR in order to study the prevention and the treatment of other chronic diabetic complications. One of the central pathological changes is the adherency and aggregation of blood leucocyte and retina micrangium endotheliocyte in it's occurrence and development, although DR has complicated pathogenesy and is the result of multiple factors synergy. Among all adhesion molecules sereted by endotheliocyte, intercellular adhesion molecule-1(ICAM-1) and vascular cell adhesion molecule-1(VCAM-1) have considerable effect on the occurrence and development of diabetic retinopathy.To investigate on the mechanism of the prevention and cure of DR by aspirin through observing the levels of blood suger, hemorheology, and the influence of aspirin on the expression of intercellular adhesion molecular-1 (ICAM-1) in the streptozocin(STZ)-induced diabetic mellitus (DM) rats' retina.Methods : Diabetes was induced in male SD rats(180-220g) by injection of streptozocin(STZ,60mg/kg) after fasting overnight. Normal control animals received citrate buffer(n=9,NC). Diabetes was diagnosedbased on blood glucose concentration (higher than 16.9mmol/L) when STZ-treated rats were at 72 hours. Diabetic rats were diveded randomly into two groups: diabetic control group(n=10,DM); diabetic group treated with aspirin(n=10,A). After treating with 12 weeks, all animals were sacrificed. The follow parameters were measured: body weight, the levles of blood sugar, ICAM-1 protein expression were detected by western-blot and immunhistochemical SABC and HE method respectively. Finally, they were analyzed by computer-picture analysis system.Results:(1)The levels of blood glucose in DM group were higher than that in NC group(p<0.01). The levels of blood glucose in A group were decreased significantly than DM group. (2)Morphological observation of retina with the microscope: the structure of the normal rat retina was divided into 10 layers, each layer arranged in regularity; the hierarchical structure in retina of DM rats was loosened obviously, ganglionic layer of retina and inner nuclear layer edema and isolation between the outer and the inner nuclear layer. (3)Western-blot: there expressed adhesion molecules in each group. Compared with NC, adhesion molecules increasing expressed in DM group. After treatment with aspirin, the expressed of adhesion molecules depressed significantly.Conclusions: In STZ induced SD diabetic rats, the expression of ICAM-1 increased in the retina on the protein level. Aspirin repressed the expression of ICAM-1.