3-hydroxykynurenin concentration changes in retina after partial optic nerve crush and NMDA-induced RGC damage in rat

摘要

Purpose: To investigate concentration of 3-hydroxykynurenin (3OH-K) in retinas in a rat model of partial optic nerve crush (PONC) and NMDA-induced damage of rat retinal ganglion cells (RGCs) Methods: Female Brown Norway rats (Charles River, Wilmington, MA), body weight 140-170g were housed under a 12-hour light-dark cycle. The animals were treated in accordance with the ARVO Statement for the Use of Animals in Vision Research. The rats were anesthetized with an intraperitoneal injection of chloral hydrate (7%, 6ml/kg body weight), local anaesthesia in form of eye drops were also applied. One group of animals received intravitreal NMDA (2?μl, 10mM). Control eye received PBS (2?μl). In the other group of animals PONC or sham procedure in control eye were performed. On day 2 and 7 eyes were enucleated, retinas dissected and immediately deep frozen. 3OH-K concentration was measured with HPLC. Results: Retinal concentration of 3OH-K after 2 days was significantly higher in retinas 2 days after both NMDA injection and PONC (27.4% and 40% increases respectively, P0.05, U Mann-Whitney). After 7 days 3OH-K concentration was significantly higher in retinas after NMDA injection (217% increase, P0.01) but not after PONC (21% increase, P0.05). Conclusions: Retinal concentration of 3OH-K increases in response both to PONC and NMDA-induced RGC damage in rat, suggesting its involvement in RGC degenerative processes.