Effects of peroxynitrite on rabbit cornea.
BACKGROUND
Nitric oxide (NO) reacts rapidly with the superoxide anion to generate peroxynitrite, which has been found in the aqueous humor in eyes with uveitis. We evaluated the functional and anatomic effects of peroxynitrite on rabbit cornea.


METHODS
One eye of each rabbit received an anterior chamber injection of 3-morpholinosydonimine N-ethylcarbamide (SIN-1), which simultaneously generates both NO and the superoxide anion. The corneal thickness was measured using an ultrasonic pachymeter before and after the injection. The eyes were fixed and the corneal specimens were prepared for electron microscopy.


RESULTS
Anterior chamber injections of SIN-1 caused a significant increase in the corneal thickness (25.1+/-3.0 microm) 30 min after injection. Transmission electron microscopy showed swollen mitochondria and large vacuoles in the cytoplasm, and scanning electron microscopy revealed obscuring of the mosaic pattern by increased ruffling of endothelial cell surface and borders.


CONCLUSIONS
The results suggest that peroxynitrite generated in the aqueous humor may cause corneal endothelial cell damage, which leads to transient corneal edema.
Yanagiya
N
N
Department of Ophthalmology, Asahikawa Medical College, Japan.
Akiba
J
J
Kado
M
M
Hikichi
T
T
Yoshida
A
A
D000818:Animals; D000867:Anterior Chamber / Q000187:drug effects; D015715:Corneal Edema / Q000139:chemically induced / Q000000981:diagnostic imaging / Q000473:pathology; D004728:Endothelium, Corneal / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000648:ultrastructure; D007267:Injections; D008855:Microscopy, Electron, Scanning; D008928:Mitochondria / Q000187:drug effects / Q000648:ultrastructure; D008981:Molsidomine / Q000031:analogs & derivatives / Q000494:pharmacology*; D009566:Nitrates / Q000494:pharmacology*; D020030:Nitric Oxide Donors / Q000494:pharmacology*; D011817:Rabbits; D013481:Superoxides / Q000494:pharmacology; D014463:Ultrasonography
D009566:Nitrates; D020030:Nitric Oxide Donors; D013481:Superoxides; C039642:peroxynitric acid; C002385:linsidomine; D008981:Molsidomine