Effect and safety of different concentrations of disintegrin Echistatin to early posterior capsule opacification in diabetic rabbits
10.3760/cma.j.issn.2095-0160.2014.11.004
- VernacularTitle:去整合素Echistatin对糖尿病兔早期后发性白内障的抑制作用及眼内安全性
- Author:
Guangxia, QIAN
;
Shaojian, TAN
;
Hao, LIANG
;
Yingying, CHEN
- Publication Type:Journal Article
- Keywords:
Disintegrin;
Posterior capsular opacification;
Proliferating cell nuclear antigen;
Apoptosis;
Diabetes mellitus;
Animal model
- From:Chinese Journal of Experimental Ophthalmology
2013;32(11):975-979
- CountryChina
- Language:Chinese
-
Abstract:
Background Posterior capsular opacification (PCO) is a primary cause of blurred vision after extra-capsular cataract extraction (ECCE),and there is a higher incidence of PCO in the patients with diabetes mellitus.Echistatin (Ecs) can suppress the proliferation of lens epithelial cells (LECs) and thereby inhibit the formation of PCO.However,its mechanism and safe dose deserve to study.Objective The aim of this study was to observe the inhibitory effect of different concentrations of Ecs on LECs proliferation in the early stage of PCO in diabetic rabbits and explore the safe dose of Ecs.Methods Diabetic mellitus was induced by injection of 90 mg/kg alloxan via ear vein in 15 New Zealand white rabbis.ECCE was performed in the right eyes of the rabbits.The rabbits were randomized to the control group and 5.0,7.5,10.0 and 15.0 μg/ml Ecs group according to randomized number table method.Ecs of 0.2 ml in above doses was injected into the anterior chamber after ECCE in different concentrations of Ecs groups,and 0.2 ml distilled water was used in the same way in the only diabetic rabbits as the control group.Postopeartive response of ocular anterior segment was observed and PCO was graded under the slit lamp microscope.The corneal and retinal specimens were prepared 10 days after operation for the assay of preliferative cell nuclear antigen (PCNA) expression in LECs by immunochemistry to evaluate the effective dose of Ecs.Regular histopathological examination was performed,and apoptosis of corneal endothelial cells and retinal cells was detected by TUNEL method to assess the safe concentration of Ecs.Results Different degrees of corneal edema and exudation in anterior chamber were seen in the eyes of different groups.The inflammatory response disappeared 3-5 days in the control group and 5.0 μg/ml Ecs group and 7 days in the ≥7.5 μg/ml Ecs groups.PCO was 1-2 grade in the control group and 5.0 μg/ml Ecs group and 0 grade in the ≥ 7.5 μg/ml Ecs groups.The difference in the positive expression level (absorbance,A) for PCNA in LECs was significantly different among the control group and various Ecs groups (F=18.006,P=0.001),and the positive expression level of PCNA in the ≥ 7.5 μg/ml Ecs groups was markedly reduced in comparison with that in the control group (P =0.010,0.001).Hematoxylin and eosin staining showed an normal morphology and order arrangement in corneal endothelial cells and intact structure in retinal internal limiting membrane in the groups.TUNEL assay revealed that the apoptosis values (mean A value) of corneal endothelial ceils and retinal cells in the ≤ 10.0 μg/ml Ecs groups were not significantly changed in comparison with the control group (all at P＞0.05),but the apoptosis values in the 15.0 μg/ml Ecs group were markedly higher than those in the control group (P=0.004,0.018).Conclusions Ecs can inhibit the early PCO in diabetic rabbits and show the optimal effect at the concentrations of 7.5 and 10.0 μg/ml without visible eytotoxicity to eye other tissues.Therefore,these two doses of Ees might be used for the study of long-term therapeutic effectiveness.
