TOPICAL SUBSTANCE-P AND CORNEAL EPITHELIAL WOUND CLOSURE IN THE RABBIT

Purpose. The authors determined the effect of topically applied substa nce P (SP) on the rate of corneal epithelial wound closure in the rabb it. Methods. Uniform circular lesions, 6.5 mm in diameter, were made b ilaterally in the corneal epithelium of 24 rabbits using N-heptanol. S ubstance P was applied repeatedly to one eye, and the SP1-7 fragment w as applied to the contralateral (control) eye until wound closure was obtained. Three concentrations of peptide solution (5 x 10(-5) M, 5 x 10(-4) M, and 5 x 10(-3) M) were tested in separate groups of eight an imals each. An additional eight animals received topical applications (5 x 10(-7) M) of the neurokinin-1 (NK1) specific SP receptor antagoni st CP-99,994-01 or its ineffective enantiomer CP-100,263-01. The mean rates of wound healing for each group of experimental and control eyes mere determined by linear regression and analyzed by analysis of vari ance. Results. There were no statistically significant differences in the mean rates of wound closure (range, 0.083 to 0.106 mm/hour) betwee n experimental- and control-treated corneas for any of the four groups tested. Conclusions. The topical application of SP or its NK1 recepto r antagonist has no significant effect on the fate of corneal epitheli al wound closure in the rabbit.