Search

AIM: To determine whether etomidate (ET) has a protective effect on retinal ganglion cells (RGCs) injured with hydrogen peroxide (H2O2) and to explore the potential mechanism underlying the antioxidative stress effect of ET. METHODS: Cultured RGCs were identified by double immunofluorescent labeling of microtubule-associated protein 2 and Thy1.1. An injury model of H2O2-induced RGCs oxidative stress was established in vitro. Cells were pretreated with different concentrations of ET (1, 5, and 10 μmol/L) for 4h, followed by further exposure to H2O2 at 1000 μmol/L. Cell counting kit 8 and Annexin V/propidium iodide assays were applied to detect the viabilities and apoptosis rates of the RGCs at 12, 24, and 48h after H2O2 stimulation. The levels of nitric oxide, malondialdehyde, and glutathione in culture media were measured at these time points. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blot were performed to observe the effects of ET on the messenger RNA and protein expression of inducible nitric oxide synthase (iNOS), nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase 1 (HO-1), glutathione peroxidase 1 and the level of conjugated acrolein in RGCs at 12, 24, and 48h after H2O2 stimulation and in the retina at 12h after optic nerve transection (ONT). RESULTS: The applications of 5 and 10 μmol/L of ET significantly increased the viability of RGCs. Results from qRT-PCR indicated a decrease in the expression of iNOS and an increase in the expressions of Nrf2 and HO-1 in ET-pretreated RGCs at 12, 24 and 48h after H2O2 stimulation, as well as in ET-treated retinas at 12h after ONT. Western blot analysis revealed a decrease in the expression of iNOS and levels of conjugated acrolein, along with an increase in the expressions of Nrf2 and HO-1 in ET-pretreated RGCs in vitro and ET-treated retinas in vivo. CONCLUSION: ET is a neuroprotective agent in primary cultured RGCs injured by H2O2. The effect of ET is dose-dependent with the greatest effect being at 10 μmol/L. ET plays an antioxidant role by inhibiting iNOS, up-regulating Nrf2/HO-1, decreasing the production of acrolein, and increasing the scavenge of acrolein.

AIM: To investigate the effect of cardiovascular risk factors on the occurrence of nonarteritic anterior ischemic optic neuropathy(NAION)and visual functions of the patients.METHODS: Sixty-eight patients diagnosed as initial ipsilateral NAION(68 eyes)in NAION group and another 68 patients(68 eyes)matched in age, gender and systemic diseases in Control group were selected from June 2014 to June 2016 were enrolled in this study and evaluated for their levels of homocysteine(Hcy), blood lipids, folic acid and vitamin B12, as well as carotid Doppler ultrasonography. The visual functions were also examined in patients with NAION.RESULTS: The levels of Hcy(24.8±13.9μmol/L), total plasma cholesterol(4.5±1.0mmol/L), triglyceride(2.0±0.9 mmol/L)and low-density lipoprotein(2.9±0.8mmol/L)in NAION patients were significantly higher(PPCONCLUSION: Hyperhomocysteinemia, hyperlipidemia and low vitamin B12 are the risk factors of in NAION patients. These risk factors, however, are not related to the extent of visual field damage. To some extent, the amplitude and peak latency of visual evoked potentials can reflect the extent of visual field damage.