[The effect of theanine on oxygen-induced retinal neovascularization in the neonatal rat].

PURPOSE: This study was aimed to investigate the preventive effects of theanine treatment on a rat model of oxygen-induced ischemic retinopathy (OIR). METHODS: OIR was induced by maintaining the Sprague-Dawley neonatal rats in 80% oxygen. The rats were treated once daily with gastric gavage of theanine (5 or 50 mg/kg) or distilled water (DW) from postnatal days 6 to 17. The retinal neovascularization (NV) was scored and avascular areas(AVAs) were measured as a % of total retinal area (% AVAs) at day 18. RESULTS: The % AVAs in 5 mg/kg theanine (13.2 +/- 2.8%) and 50 mg/kg theanine (9.4 +/- 2.2%, p < 0.05) treatment were lower than those in DW (18.9 +/- 2.9 %). The NV scores with 5 mg/kg theanine(4.2 +/- 0.5) or 50 mg/kg theanine (3.4 +/- 0.6) treatment were lower than those with DW (4.7 +/- 0.6). CONCLUSION: Theanine treatment suppresses the neovascularization in a rat model of OIR. These results suggest that theanine may prevent retinopathy of prematurity.