Actin in wound-healing of rabbit corneal endothelium. I. Study by immunoperoxidase method.

The distribution of actin in the rabbit cornea was examined by the indirect immunoperoxidase method using mouse monoclonal anti-actin IgM and goat anti-mouse IgM serum conjugated with peroxidase, which was stained with 4-chloronaphthol. Flat preparation of the cornea was made and the actin distribution was examined in the normal endothelium and also during wound-healing of the endothelium that took place after transcorneal freezing. In the normal cornea, the epithelial, stromal and endothelial cells contained actin in the cytoplasm. Diffuse actin staining in the endothelial cytoplasm was observed in the flat preparation of the normal endothelium. After endothelial damage, the cells adjacent to the damaged area showed a fiber-like staining of actin around the nucleus; this occurred 12 to 24 hours after the freezing. Punctate staining was seen on the 2nd day, and the intensity of the staining was maximum on the 3rd day when the wound was completely covered. On the 3rd day, fibroblast-like cells were encountered and a long fiber-like staining of actin was seen in the cytoplasm, but the staining disappeared on the 4th day. The long fiber-like and punctate staining reappeared on the 14th day. Normal staining pattern was recovered on the 28th day. These findings suggest that actin production was accelerated in the endothelial cells during the wound-healing, and that this productive activity returned to normal levels as healing was completed.