advertisement
Abstract #8772 Published in IGR 5-1
Evaluation of nitric oxide synthesis in the optic nerve head in vivo using microdialysis and high-performance liquid chromatography and its interaction with endothelin-1
Okuno T; Oku H; Sugiyama T; Goto W; Ikeda TOphthalmic Research 2003; 35: 78-83
PURPOSE: To investigate the relationship between nitric oxide synthesis and endothelin-1 (ET-1) in the optic nerve head in vivo. METHODS: A concentric microdialysis probe was inserted into the optic nerve head of a rabbit and was perfused with Ringer's solution at a constant flow rate of 2 μl/min. The perfused dialysates were collected every ten minutes, and levels of nitrite and nitrate in the ten-minute dialysate samples were measured after intravitreal injection of ET-1 (100 pmol) using high-performance liquid chromatography, based on the Griess method. RESULTS: Basal levels of nitrite and nitrate in the ten-minute dialysate were 0.08 ± 0.01 and 3.95 ± 0.50 μM, respectively. The authors confirmed that these levels were reduced by intravenous L-NAME and restored by L-arginine. Intravitreal ET-1 significantly elevated the levels of nitrate to 189% of baseline ten minutes after ET-1 application, which was inhibited by pretreatment of intravenous L-NAME (50 mg/kg). CONCLUSION: These results indicate that production of nitric oxide is closely connected with the ET-1 signaling pathway.
Dr. H. Oku, Department of Ophthalmology, Osaka Medical College, 2-7 Daigaku-cho, Takatsuki Osaka, 569-8686 Japan. hidehirooku@aol.com
Classification:
2.14 Optic disc (Part of: 2 Anatomical structures in glaucoma)
3 Laboratory methods
