The effect of sodium hyaluronate on the migration of rabbit corneal epithelium. I. An in vitro study.

The effect of sodium hyaluronate (Na-HA) on the migration of corneal epithelium was investigated in vitro using corneo-scleral sections of rabbits. The effect on migration was evaluated by the length of migrating epithelium on the cut surface of corneal stroma after incubation in media containing Na-HA of various molecular weights or concentrations. The medium concentration of Na-HA was 400 micrograms/ml, and the molecular weights were 0.4 x 10(4), 2 x 10(4), 10 x 10(4), 68 x 10(4), 102 x 10(4) and 216 x 10(4). Regarding Na-HA with a molecular weight of 102 x 10(4); media containing Na-HA at concentrations of 50, 100, 200, 400, 800, 2000 and 4000 micrograms/ml were also investigated. When the concentration of Na-HA was 400 micrograms/ml, Na-HA with molecular weights of over 68 x 10(4) accelerated significantly the epithelial migration. Regarding Na-HA with a molecular weight of 102 x 10(4), acceleration was observed at concentrations of 200, 400 and 800 micrograms/ml. Furthermore, the concentration of fibronectin (FN) in medium containing the effective Na-HA was significantly lower than that in the control medium after the incubation. These results suggest a possibility that the accelerative effect of Na-HA depends on the reduction of FN release from the cornea or the facilitation of FN deposition on the cornea.