Topically applied naltrexone restores corneal reepithelialization in diabetic rats.
Journal
  Journal of ocular pharmacology and therapeutics : the official journal of the Association for Ocular Pharmacology and Therapeutics.
Citation
  J Ocul Pharmacol Ther. 23(2):89-102
Publication date
  2007 Apr
Authors
  Klocek MS
Sassani JW
McLaughlin PJ
Zagon IS
Investigators
  Patricia J. McLaughlin
Joseph W. Sassani
Ian S. Zagon
Grant agencies
  National Eye Institute
Grants
  NEI EY016666
MeSH headings
  Corneal Ulcer
Diabetes Mellitus, Experimental
Epithelium, Corneal
Naltrexone
Narcotic Antagonists
MeSH qualifiers
  drug therapy
complications
drug effects
pharmacology
Abstract
  PURPOSE: Complications of diabetes include an increased risk of delayed corneal epithelial wound healing. This study examined the efficacy of naltrexone (NTX), an opioid antagonist, by topical application in facilitating the repair of such lesions. METHODS: NTX, in concentrations of 10(-4), 10(-5), or 10(-6) M, was administered topically 4 times per day for 7 days to the abraded eye of type 1 diabetic rats (DB), DB animals receiving insulin and normoglycemic (DB-IN), and nondiabetic (Normal) rats, beginning 8 weeks following the onset of diabetes. RESULTS: In comparison to DB animals receiving sterile vehicle (SV), DB-NTX rats had 25%-83% smaller defects, a reduction of 24 h (approximately 33%) in closure time, and 20%-42% faster healing rates. DB rats receiving 10(-4) and 10(-5) M NTX were equal to, or surpassed, Normal animals in all parameters of wound closure. NTX also enhanced wound repair in DB-IN and Normal animals relative to their respective SV group. No adverse effects of NTX administration on a variety of noninvasive or invasive measures were discerned. Conclusions: Topically applied NTX is not only feasible, but also effective over a one hundredfold dosage for accelerating corneal wound healing in diabetic subjects.