Effects Of Dexamethasone Injection In Different Ways On Drug Concentration And Blood Glucose In Rats With Type 2 Diabetes Mellitus

Objective:To evaluate the effects of injection of dexamethasone by peribular,retrobulbular and subconjunctival approaches on local drug concentration and blood glucose in type 2 diabetic SD rats.Methods:The concentration of dexamethasone in water.SD rats with type 2 diabetes mellitus（n=192）were randomly divided into the experimental group and the control group on average.Group A was the peribulb-injected dexamethasone group,group B wasthepost-bulb-injecteddexamethasonegroup,groupCwasthe subconjunctivia-injected dexamethasone group,group A was the peribulb-injected normal saline group,and group B was the post-bulb-injected normal saline group.Group c was the subconjunctival saline injection group.Local injection of dexamethasone or saline 0.1ml was given to the eyes according to the groups.Venous tail blood was collected at each time point at 0h,2h,4h,8h,12h,and 24h after the injection of 8 rats according to the grouping.At the beginning of injection,aqueous humor samples were taken from the anterior chamber of 4 rats at 0.5h,2h,4h,8h,12h and 24h,respectively,and the concentration of dexamethasone in aqueous humor of rats at different time points was determined by HPLC.Result:After the sub-tenon/ball/subconjunctival injection of dexamethasone,the blood glucose concentration of T2DM rats between the experimental group and the control group was statistically significant.(F_sub-tenon=6.166,F_ball=4.849,F_{subconjunctival}=4.624;P_sub-tenon=0.026,P_ball=0.045,P_{subconjunctival}=0.049.Blood glucose concentrations of T2DM rats in the experimental group after dexamethasone injection through different channels showed no statistically significant difference（F=0.151,P=0.861）,while blood glucose concentrations of T2DM rats in the control group after normal saline injection through different channels showed no statistically significant difference（F=0.12,P=0.888）.After injection of dexamethasone in different ways,the concentration peak in the subbulbar conjunctiva group of T2DM rats（957.59 5.67ng/ml）and the concentration peak in the subbulbar conjunctiva group of T2DM rats（859.60 4.41 ng/ml）after injection of>（732.38 26.93ng/ml）.After para-bulbar injection for 0.5-12h,the concentration of dexamethasone in binocular chamber water of rats A and a showed statistically significant difference（P<0.05）.24h after injection,there was no statistically significant difference in the concentration of dexamethasone in binocular aqueous Chambers between groups A and a（P>0.05）.0.5¹2h after injection,the concentration of dexamethasone in binocular chamber water of rats B and b showed statistically significant difference（P<0.05）.At 24h after injection,there was no statistically significant difference in the concentration of dexamethasone in binocular aqueous Chambers between groups B and b（P>0.05）.After subconjunctival injection for 0.5-24h,the concentration of dexamethasone in binocular aqueous humor of rats in groups C and c showed statistically significant difference（P<0.05）.After dexamethasone injection for0.5h²4h,the concentration of dexamethasone in aqueous Chambers of rats with different T2DM pathways showed statistically significant difference（P<0.05）.After the injection of normal saline for 0.5-24h,there was no statistically significant difference in the concentration of dexamethasone in rats with different T2DM channels（P>0.05）.Conclusion:Blood glucose of T2DM rats was increased after dexamethasone injection through different channels,and there was no significant difference in blood glucose changes between different channels.The subconjunctival injection route reached higher concentration in the anterior chamber than the peribulbar and retrobulbar injection routes.