The healing mechanism of corneal endothelium after alkali burn was not completely understood. Rabbit cornea was burned with 1N sodium hydxoside for 1 minute. Endothelial F-actin was stained with NBD-phallacidin in regular sequence to find out the details of endothelial healing after alkali burn. F-actin was completely destroyed leaving a sharp margin against the unaffected area 1 hour after the burn. In the 3, 5 and 7 day specimens, highly active F-actin reactions were noted at the wound margin. New multiple F-actin layers, arising from the intact endothelium near the wound margin, were noted in the 9 day specimen. In the 8 1/2 month specimen, the endothelial defected area was covered by large primitive cells, each of which showed F-actin fiber bundles in the cytoplasm with a large nuclear shadow. Nearly all of the large primitive cells showed F-actin fibers arranged in shapes of cell junctions. Twelve months after the burn, endothelial defects were not found. Nearly all of the endothelial cells were normal in size and shape except for some mushroom-like projections toward the anterior chamber in some areas. Nineteen months after the burn, the endothelial cells were normal. Endothelial wound healing process can be continued even 1 year after the alkali burn in rabbit cornea.
Actins/*metabolism ; Animal ; Burns, Chemical/*metabolism ; Endothelium, Corneal/injuries/*metabolis ; Eye Burns/chemically induced/*metabolism ; Female ; Male ; Rabbits ; Sodium Hydroxide/*adverse effects ; Support, Non-U.S. Gov't ; Wound Healing

The expression of VEGF-C and molecular mechanisms of lymphangiogenesis in rat cornea after alkali injury was studied. The rat alkali injured corneal models were made. Under electron microscopy, the lymphatic vessels in the rat injured corneas were examined. The expression of VEGF-C proteins was detected by using immunohistochemical assay at day 1, 3, 5, 7, 9 after injury. The expression levels of VEGF-C mRNA were quantified with reverse transcription polymerase chain reaction (RT-PCR). The results showed that the lymphatic vessels were found in the injured rat corneas 14 days after the injury. The VEGF-C protein was detectable 3 days after injury, reached the peak 5 days after injury, and gradually decreased. In the control group, no VEGF-C proteins were detected. The VEGF-C mRNA was minimally detected in the normal rat corneas, but it was highly expressed 5 days after the injury. The difference was statistically significant. It was concluded that VEGF-C might be one of the most important relevant factors in corneal lymphangiogenesis after alkali injury.
Animals ; Biomarkers ; Burns, Chemical ; metabolism ; Cornea ; metabolism ; Corneal Injuries ; Eye Burns ; chemically induced ; metabolism ; RNA, Messenger ; biosynthesis ; genetics ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Vascular Endothelial Growth Factor C ; biosynthesis ; genetics