Endothelin-1 promotes corneal epithelial wound healing in rabbits

This study is an attempt to determine the effect of endothelin-1 (ET-1)-containing eyedrops on the rate of corneal epithelial wound closure in rabbits. After corneal epithelial debridement of about 50-60 mm2 with n-heptanol, eyedrops containing either 10(-8) M ET-1 or 10(-6) M ET-1 were applied at five different times for the next three days. The wound was serially photographed 12, 24, 36, 48, 60 and 72 hours later to measure the extent of healing with a computerized planimeter. The respective wound healing rate at 10(-6) and 10(-8) M ET-1 was 1.293 +/- 0.040 mm2/hour (n = 11) and 1.262 +/- 0.087 mm2/hour (n = 6), respectively. These rates were 29% (p < 0.01) and 26% (p < 0.05) above the control value, 1.005 +/- 0.063 mm2/hour (n = 13). Reepithelialization was not associated with any epithelial hyperplasia, neovascularization or conjunctival hyperemia. These results suggest that ET-1-containing eyedrops could be of therapeutic value in the remedy of corneal epithelial defects.