Prevention and treatment of nitric oxide synthetase inhibitor on galactose cataract in rat / 中华实验眼科杂志

ABSTRACT

Background Researches showed that the content of nitric oxide (NO) and nitric oxide synthetase (NOS) increases in blood,aqueous humor and tear of cataract patient.But the function of NO and NOS in cataract formation is still elusive.Objective The aim of this study was to explore the prevention and treatment effect of NOS inhibitor,1-nitro-arginine methyl ester (L-NAME),on galactose cataract.Methods Sixty clean three-week-old Wistar rats were equally and randomly divided into 3 groups.0.9％ Normal saline solution (30 ml/kg) was subcutaneously injected every day for 30 days in the rats of the control group,and 50％ of D-galactose solution (30 ml/kg) was used in the rats of the model and L-NAME group at the same way.L-NAME eye drops was simultaneously administered in the L-NAME group 3 times per day for 30 days.The eyes of the rats were examined under the slit lamp in 10,20 and 30 days,and the degree of lens opacification was scored.Lenses of the rats were obtained at the end of this experiment for the detect of NO,NOS contents.Flow cytometry was used to assay the caspase-3 level of rat lens.Repeated measurement two factor analysis of variance was used to analyze the difference of lens opacification scores in different groups and different time points,and one-way ANOVA was used to analyze the differences of NO,NOS and caspase-3 contents in lens among the groups.Results Lens opacification appeared in 10 days after injection of 50％ D-galactose solution in the rats of the model group and L-NAME group.Lens opacification score was higher among the different groups and different time points (Ftime =435.251,P =0.000 ;Fgroup =395.120,P=0.000).NO content in the lens was (0.45±0.15) μmol/g,(2.67 ± 0.47) μmol/g and (1.68±0.34) μmol/g in the control group,model group and L-NAME group,showing a significant difference (F=58.872,P=0.000).The NOS contents in the lens was (0.0160±0.0020) U/ml,(0.0370±0.0040) U/ml and (0.0270±0.0010) U/ml in the control group,model group and L-NAME group,showing a significant difference (F =66.174,P=0.000).Caspase-3 contents in the lens was (339.4 ± 37.9),(697.7 ± 46.5) and (650.7 ± 53.1),Showing a significant difference among them (F =100.005,P =0.000).Conclusions The increase of NO,NOS and caspase3 levels are associated with lens opacification.Topical administration of L-NAME eye drops can down-regulate NOS content in lens,reduce the NO formation and inhibit the apoptosis of lens epithelial cells.