| Objective To evaluate the effects of C5 a and PMX205 on the NMDA(N-methyl-D-aspartate)-induced retinal ganglion cells(RGCs) excitatory injury.Methods Sixty-five adult Sprague Dawley rats were randomly divided into four groups. NMDA was injected into intravitreal with 3ul(40m M, 120nmol/l) to make excitatory model(0.1M PBS as control). PMX205 was injected into intraperitoneal in a dose of 1.0mg/kg at 24 h before and after NMDA injected into intravitreal. The eyes of each group were enucleated at 1h, 12 h, 24 h and 48 h after intravitreal injection respectively. Hematoxylin/eosin staining of retina cross-sections was carried to record the morphological changes. ELISA was used to detect the concentration of C5 a in the retinal tissue of each group. The Real-time quantitative PCR was exployed to assay the level of Brn3 a m RNA to access the extent of RGCs,injury.Results 1.Hematoxylin/eosin staining: The staining of blank control group retinal tissues were uniform, the structures were clear, cells of every layer were in alignment and eumorphism. In the NMDA groups, the gap between the nucleus and the cell membrane was widening, disordered arrangement was aggravating, the number of RGCs was decreased and the thickness of inner plexiform layer was thinner progressively along with the increased processing time. By contrast, in PMX205+NMDA groups, the aboved injured changes were slighter obviously. 2.ELISA: Compared with the blank control groups, the content of C5 a in NMDA groups’ retinal tissues were higher. At 24 h,the level of C5 a came to a head. At 48 h, it began to decrease. Except that there was no statistical difference between the blank control group and NMDA group at 1h after treatment(p=0.06), the remaining processing time groups had statistically significant difference(p<0.05).3. Real-time quantitative PCR: Compared with the blank control, the expression of Brn3 a m RNA was lower in every group dealt with NMDA. Moreover, the differences had dramatic statistical significance(p<0.01). While the level of Brn3 a m RNA in PMX205+NMDA groups were higher than the NMDA groups at the same processing time. Meanwhile, there were significant difference through the statistical analysis(p<0.01) in addition to the 1h after injection(p=0.07). It’s worth noting that there was statistical difference between the PMX205+NMDA groups and the blank control group(p<0.01).Conclusion C5 a, the segment resulted from complement system activation, may participate in the NMDA-induced RGCs’ excitatory injury. While, its specific receptor antagonist, PMX205, can inhibit the injury at a certain extent. |
