Neuroprotection Of Jua On The Rat Retinal Ganglion Cells In Acute Intraocular Hypertention Model

Purpose: To evaluate the potential neuroprotective effect of Jujuboside A (JuA) on the rat retinal ganglion cells (RGCs) in acute intraocular hypertention model.Methods: 54 Sprague Dawley (SD) rats, regardless of their gender and weighing 200±20g, were randomly assigned into 3 groups:blank control group(n=6,killed directly without any treatment);control group(n=24,injection of same volume of normal saline via tail vein at 9:00 everyday); test group(n=24,injection of 20 mg/kg JuA via tail vein at 9:00 everyday).Either of bilateral eyes was randomly made into the acute high intraocular pressure(IOP) model using the method of normal saline perfusion into anterior chamber until the IOP reached 100 mmHg,then sustained the IOP for 60 minutes.All of the rats were killed respectively and the eyeballs were enucleated at different observation periods after the model was successfully established(6h,24h,48h,72h).The histological changes of retina were observed by HE staining;the expression and distribution of apoptotic cells and NMDAR1 were observed by using TUNEL detection and immunohistochemistry;the NMDAR1 mRNA was measured by RT-PCR;the glumatic acid content of the retina analysed by the HPLC.Results:The acute high intraocular pressure damaged the inner retina and the retinal ganglion cells apoptosis.There was less apoptotic cells in the test group than those in the control group;Glutamate levels in rat retina was increased after intravitreal injection. Glutamate levels in test group was decreased than in contral group, the difference was statistically significant (p < 0.01).There are significant differences between the test group and the contral group at different times(p < 0.01),time and drug interactions obvious;The expressions of NMDAR1 mRNA and the protein level were increased after intravitreal injection, the control group was significant higher than the blank control group at 48 hours(p < 0.01),the test group was significant lower than the contral group at 48 hours(p < 0.05).Conclusions: The acute high intraocular pressure damaged the inner retina and the retinal ganglion cells apoptosis.While JuA pretreatment can lessen the damage and the cell apoptosis,and hinder the rise of retinal glutamate levels and the expression of NMDAR1.JuA may play a protective role on the rentina in glaucoma pathology.