Doly M, Droy-Lefaix M T, Braquet P
Laboratoire de Biophysique (Inserm U. 71), Facultés de Médecine et de Pharmacie, Clermont-Ferrand, France.
EXS. 1992;62:299-307. doi: 10.1007/978-3-0348-7460-1_30.
The authors describe the alterations usually associated with diabetic retinopathy. They concern the classical thickening of the basal membrane of retinal capillaries and the associated modification of retinal vessel permeability. These alterations correspond to the blood-retinal barrier disruption. The authors then discuss the participation of oxygenated free radicals in the pathogenesis of diabetic retinopathy. They report several experimental studies establishing such a participation and finally describe their own results obtained on a model of retinas isolated from alloxan-induced diabetic rats. After one month of evolution, the electroretinograms (ERG) recorded on isolated retinas from diabetic rats had an amplitude about 20% lower than the controls, whereas after two months of diabetes, this decrease was about 60%. Under these conditions, the authors tested the protective properties of Ginkgo biloba extract (EGb 761) on their model. They observed that in EGb-treated animals (100 mg/kg/day), the ERG had a significantly (p less than 0.001) greater amplitude than untreated animals after two months of diabetes evolution. In conclusion, the authors discuss the possible utilization of a free radical scavenger, such as EGb 761, in the prevention of the retinal impairment in diabetes.
作者描述了通常与糖尿病视网膜病变相关的改变。这些改变涉及视网膜毛细血管基底膜的典型增厚以及视网膜血管通透性的相关改变。这些改变对应于血视网膜屏障的破坏。作者随后讨论了氧化自由基在糖尿病视网膜病变发病机制中的作用。他们报告了几项证实这种作用的实验研究，最后描述了他们在从四氧嘧啶诱导的糖尿病大鼠分离的视网膜模型上获得的自身结果。经过一个月的病程，糖尿病大鼠分离视网膜上记录的视网膜电图（ERG）振幅比对照组低约20%，而糖尿病两个月后，这种降低约为60%。在这些条件下，作者在其模型上测试了银杏叶提取物（EGb 761）的保护特性。他们观察到，在糖尿病病程两个月后，经EGb治疗的动物（100毫克/千克/天）的ERG振幅比未治疗动物显著（p小于0.001）更高。总之，作者讨论了自由基清除剂如EGb 761在预防糖尿病视网膜损伤方面的可能应用。
