Inhibitory effect of an angiotensin II receptor antagonist in diabetic retinopathy

背景资料：方法：采用链脲佐菌素（STZ）诱导糖尿病大鼠模型，随机分为两组，每组10只。第一组（n=6）不接受任何药物治疗;第二组（n=6）给予新鲜饮用水补充氯沙坦（5 mg/kg/d）4周。6只未注射STZ或给予药物的大鼠作为对照。干预4周后，用吖啶橙子数字荧光成像观察视网膜中白细胞动态。结果：糖尿病组视网膜白细胞滞留数明显低于对照组，视网膜白细胞滞留数明显低于正常对照组，视网膜白细胞滞留数明显低于正常对照组。（6.1（SD1.4）个细胞/mm 2）与对照组相比显著增加（2.8（1.2）个细胞/mm 2;p=0.005）和氯沙坦治疗的糖尿病大鼠结论：血管紧张素Ⅱ受体拮抗剂氯沙坦可抑制糖尿病视网膜白细胞滞留。作者证明，氯沙坦可能在预防糖尿病视网膜病变的发展方面具有治疗效果。血管紧张素受体拮抗剂在预防糖尿病视网膜病变发展中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.