| ObjectTo study the protection functions and mechanisms of berbamine for retinal neurocyte injury of rabbit acute ocular hypertension.Method96 new zealand white rabbits were divided randomLy into 6 group: normal control group without any treatments,negative control group was lavaged with 10mL of normal saline,positive control group was lavaged with 10mL of normal saline mixing with Verapamil(20mg/kg),BER A group was lavaged with 10mL of normal saline mixing with Berbamine (80mg/kg), while BER B group (100mg/kg), BER C group(120mg/kg). These treatments were done before 1 h of being modeled or once daily postop. All groups except normal control group were done paracentesis for anterior chamber of right eye and lavaged with normal saline,and then the model of ischemia-reperfusion injury in rabbits was established by pressor method with blood pressure gauge. The rabbits (4/group) were executed after immediate time,24h,72h and 168h of operation respectively.Then, according to different phase after operation, ocular tensions were measured with applanometer, the content of Ca2+ of amphiblestrodes tissue was determined by flame atomic absorption spectrophotometry , the thickness of amphiblestrodes was observed with HE staining,the activity of RGCs was detected by AgNOR staining.Result1. Using paracentesis for anterior chamber and being lavaged with normal saline togather with pressor method by blood pressure gaugein could heighten ocular tension of rabbits and keep on about 110mmHg .2. The content of Ca2+ of rabbit amphiblestrodes tissue inischemia-reperfusion injury increased after immediate time of operation in treated groups,comparing with normal control group, there were significant differences(P <0.05). With time going, the content of Ca2+ in the negative group increased and keeped stable in higher level in 168h. With the dose of Berbamine increaseing, the content of Ca2+ decreased obviously till to normal level.During 168h, BERC group compared with normal control group and positive group,which has intensive depressant effect for inflow of Ca2+ in any time,there was no significant differences (P >0.05).3. During nonage,the changes of histology in negative control group showed retinal edema,which was obvious in retinal nerve fibre layer and plexiform layer. While in advanced stage, the entoretina depauperated and became attenuation,and the retinal ganglial cells decreased.Comparing negative group ,the changes of histology in other groups showed that retinal edema was more mild in nonage, the entoretina was more thick during advanced stage and the RGCs were more in number. In 168h, retina in BERC group and positive group recovered, the thickness of nerve fiber layerthere and number of RGCs had no significant differences comparing with normal control group(P >0.05).4. During immediate time, the silver staining grana in cell nucleus of RGCs in all groups had no marked change. During 24h,the silver staining grana in cell nucleus of RGCs in negative control group reduced obviously,with time going,the silver staining grana decreased gradually. The silver staining grana in cell nucleus of RGCs in positive group,BER A,BER B and BER C group less than normal control group(P <0.05),but more than negative control group(P <0.05). In 168h, the activity of RGCs in BERC group and positive group recovered roughly, and the silver staining grana in cell nucleus of RGCs had no significant differences (P >0.05).Conclusion1. Using paracentesis for anterior chamber and being lavaged with normal saline togather with pressor method by blood pressure gaugein could obtain the ischemia-reperfusion retinal injury model,which is lasting,stable and controllable.2. Calcium overload of retinal neurocyte may participate the apoptosis of RGCs after ischemia-reperfusion injury.3. The main change of histology in retinal injury showed that entoretina became thin and the RGCs decreased in number.4. Berbamine can lessen the effect of attenuation of entoretina,reduce the number of RGCs and provid protection for RGCs partly.5. Berbamine protect retinal neurons probablly by inhibiting calcium influx in retinal cells,which show concentration dependent.
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