The protective effects of extract of panax notoginseng saponins on retinal ganglion cells of the continuous high Intraocular Pressure in rats

Objective To investigate protective effects and mechanisms of extract of PNS on retinal ganglion cells injury induced by continuous high intraocular pressure (IOP) in rats.Methods 80 healthy Sprague-Dawley ( SD) rats were randomly divided into four groups to establish rat model of high intraocular pressure with 4,8,12,16,20 weeks which there were cauterizing episcleral veins combined 5-Fu and only cauterizing episcleral veins.All the rats intraocular pressure was measured and recorded regularly.After 4,8,12,16,20 weeks,all rats were killed and the eyeballs were removed and to assay apoptosis of RGCs by TUNEL,to detect the activity of RGCs AgNOR staining and to discover the expression of caspase-9 by immunohistochemical detections.Results The IOP was almostly more than 36.55±0.27mmHg.The order of the number of TUNEL-positive cells in retinal ganglion cell layer,compared with the normal control group,there was a significant difference.Stained grains there was no significant difference between the combined treatment group and normal control group (P>0.05).The expression of caspase-9 protein in the saline group,treatment group and combined treatment group was obviously enhanced according to the normal control group.Conclusion The sustainable and stable rat model of high intraocular pressure could be established by cauterization of episcleral veins whih subconjunctival injection 5-Fu.PNS had significant protective effects in RCCs injury caused by the persistent high intraocular pressure.If controlling intraocular pressure with drugs which could lower the IOP,the protective effects of PNS on RGCs would be more prominent.PNS could inhibit the expression of Caspase-9 in the rat RGCs to protect RGCs. Key words: Panax notoginseng saponins; Continuous high Intraocular Pressure; Retinal ganglion cells