Inhibitory effect of an angiotensin II receptor antagonist in diabetic retinopathy

背景：定量评价氯沙坦对糖尿病大鼠视网膜微循环白细胞卡压的治疗作用。方法：用链脲佐菌素(STZ)诱导糖尿病大鼠模型后，将大鼠分为两组。第一组(n=6)不给予任何药物治疗，第二组(n=6)在饮水中加入氯沙坦(5 mg/kg/d)，疗程4周。6只没有注射STZ或给药的大鼠作为对照。干预4周后，用吖啶橙数字荧光摄影仪观察视网膜内白细胞动态变化。结果：未治疗的糖尿病大鼠视网膜白细胞捕获量(6.1个/mm~2)显著高于对照组(2.8个/mm~2；p=0.005)和losartan(3.1(0.9)cells/mm2；p=0.0002).Conclusions治疗组：血管紧张素Ⅱ受体拮抗剂氯沙坦可抑制糖尿病大鼠视网膜白细胞捕获量的增加。作者证明，氯沙坦可能具有预防糖尿病视网膜病变发展的疗效。血管紧张素受体拮抗剂预防糖尿病视网膜病变的作用还需要进一步的临床研究。

Background : The effectiveness of losartan for the treatment of leukocyte entrapment in the retinal microcirculation of diabetic rats was evaluated quantitatively.Methods : After diabetes was induced by injection of streptozotocin(STZ), the rats were divided into two subgroups. The first subgroup(n=6), received no medications ; the second subgroup(n=6) was given fresh drinking water supplemented with losartan(5mg/kg/day) for 4 weeks. Six rats that were not injected with STZ or given medications served as controls. 4 weeks after intervention leukocyte dynamics in the retina were observed using acridme orange digital fluorography. Leukocyte entrapment in the retina was compared among the three groups.Results : In the untreated diabetic rats, the number of trapped leukocytes(6.1(SD1.4)cells/mm2) increased significantly compared with control rats(2.8(1.2) cells/mm2;p=0.005) and diabetic rats treated with losartan(3.1(0.9)cells/mm2;p=0.0002).Conclusions : Losartan, an AT1 angiotensin II receptor antagonist, inhibited increased leukocyte entrapment in the diabetic retina. The authors demonstrated that losartan may have therapeutic efficacy in preventing development of diabetic retinopathy. Futher clinical studies of the effect of the angiotensin receptor antagonist on preventin development of diabetic retinopathy are needed.