Effect of MK801 and CNQX on Retinal Injury Induced by Ischemia, NMDA, or Kainate

ABSTRACT

To examine the protection of retinal cell death by glutamate antagonists in vivo, this study was carried out in pressure-induced ischemia model. Firstly, we observed that ischemia resulted in the similar retinaldamage to the injuries caused by NMAD and Kainate toxicity. Secondly, the retinal cell death caused by ischemia was prevented by MK801 and CNQX, glutamate antagonists for NMDA and Kainate excitotoxicity, respectively at 24hr after ischemia. MK801 was shown to prevent the cell death in ganglion cell layer and CNQX in inner unclear layer. In addition, the combination of CNQX and MK801 protected the retina neuronal cell from ischemic injury better than when they were applied separately. The partial protection of retinal cell death by glutamate antagonists in ischemia model indicates that glutamate eoxicity as well as other cell death mechanism such as apoptosis mediates ischemia induced retinal cell death. Thus, cell death by other mechanism must be also blocked in order to prevent retinal cell death, completely.