Blunt Trauma To The Retina And In Vitro Cultured M¨¹ller Cells Glutamate Levels

Ocular blunt trauma caused by mechanical blunt power is a common and frequently-occurring disease in clinical medicine and could injure sense of sight seriously. Some doctors supposed the mechanism of injury has been relation to the exitatory neurotoxicity of glutamate to retina in trauma.Retinal muller cell is the most important supportable cell in retina. It pierces through the whole layer of retina, comprises brace of retina and has played a key role in the metabolic detoxication of excitatory amino acid-glutamate because it transports excessive glutamate extracellular space in time.Glutamate is the predominant excitatory nerve transmitter substances but a potential excitotoxin in the same time owing to causing damage even death of nerve cells when it is overdosed. The toxicity is dose-dependant. Overdose is happened when retinal cell is suffered hypoxia or/and ocular hypertension because glutamate released more but absorbability by muller cell is less in this time. The superfluous glutamate outside cell results in excessive Ca~2+ entering cell via receptor-mediated signal transduction. Nerve cell will be injured by hypercalcemia inside-cell. It has been proved that excitatory toxicity of glutamate played a significant role in retinal ischemia and ocular hypertension, but there is little research in ocular blunt trauma. In our study, the changes of glutamate quantity are observed in the blunted retinal muller cells in primary culture and ocular blunt trauma rabbits which eyes are remedied by calcium channel blockers. Our study provided an experimental basis for interpretation of effect of glutamate on muller cells in ocular blunt trauma and for application of calcium channel blockers in clinical treatment of ocular blunt trauma.The main results and conclusions: a new method is established for primary culture of purified retinal muller cell by rinsing repeatedly with low concentration trypsin in culture method. This method could be applied for other kinds of primary cells culture. The changes of glutamate quatity in extracellular space of contused muller cell and the result indicates that the biological behavior of invitro cultured miiller cell is different from that of invivo retinal muller cell, because we observed that muller cell could transport excessive glutamate but the ability of transport is no statistical difference after contused. The changes of glutamate concentration of retina in ocular blunt trauma rabbits are closely related with clinical signs. In the first time we medicated ocular blunt trauma rabbits with calcium channel blockers and found glutamate quatity in retina could be extremely reduced if contused eyes were given an injection of this medicine in early state of ocular blunt trauma. This study provided an experimental basis for clinical treatment of ocular blunt'trauma.