J Korean Med Sci.  2002 Jun;17(3):389-394. 10.3346/jkms.2002.17.3.389.

The Role of Nitric Oxide in Ocular Surface Cells

• Kim JC
• Park GS
• Kim JK
• Kim YM

• KMID: 1101556
• DOI: http://doi.org/10.3346/jkms.2002.17.3.389

Abstract

The role of nitric oxide (NO) in the ocular surface remains unknown. We investigated the conditions leading to an increase of NO generation in tear and the main sources of NO in ocular surface tissue. We evaluated the dual action (cell survival or cell death) of NO depending on its amount. We measured the concentration of nitrite plus nitrate in the tears of ocular surface diseases and examined the main source of nitric oxide synthase (NOS). When cultured human corneal fibroblast were treated with NO producing donor with or without serum, the viabilities of cells was studied. We found that the main sources of NO in ocular surface tissue were corneal epithelium, fibroblast, endothelium, and inflammatory cells. Three forms of NOS (eNOS, bNOS, and iNOS) were expressed in experimentally induced inflammation. In the fibroblast culture system, the NO donor (SNAP, S-nitroso-N-acetyl-D, L-penicillamine) prevented the death of corneal fibroblast cells caused by serum deprivation in a dose dependent manner up to 500 micrometer SNAP, but a higher dose decreased cell viability. This study suggested that NO might act as a doubleedged sword in ocular surface diseases depending on the degree of inflammation related with NO concentration.

Keyword

Cell Survival; Nitric Oxide; Nitric-Oxide Synthase (NOS); Ocular Surface Tissue

MeSH Terms

Animals
Apoptosis/drug effects/physiology
Aqueous Humor/metabolism
Blood Proteins/pharmacology
Cell Survival/drug effects/physiology
Cells, Cultured
Epithelium, Corneal/*cytology/*enzymology
Fibroblasts/cytology/enzymology
Humans
Nitric Oxide/biosynthesis/*physiology
Nitric Oxide Donors/pharmacology
Nitric Oxide Synthase/metabolism
Nitric Oxide Synthase Type I
Nitric Oxide Synthase Type II
Nitric Oxide Synthase Type III
Penicillamine/*analogs & derivatives/pharmacology
Peroxynitrous Acid/biosynthesis
Rabbits
Tears/metabolism
Uveitis/metabolism