Review Article
The Yin and Yang of the Opioid Growth Regulatory System: Focus on Diabetes—The Lorenz E. Zimmerman Tribute Lecture
Figure 11
Toxicity evaluation of NTX-treated rat cornea. Corneal thickness, endothelial cell number, and evidence of epithelial apoptosis, necrosis, or organization were determined for topical 10−3 to 10−7 M NTX administered q.i.d. × 7 days to corneas of type 1 diabetic rats. Photomicrographs of histological sections of the rat peripheral cornea stained with hematoxylin and eosin from animals in normal, diabetic (DB), and diabetic-insulin (DB-IN) groups at 2 weeks after the conclusion of 7-day exposure (4 times daily) of 103 M naltrexone (NTX) or sterile vehicle (SV). The morphology of the cells and tissues was similar between groups, and no pathologic changes were detected in corneas exposed to vehicle or 103–107 M NTX (data not shown for treatment with 10−4, 10−5, 10−6, or 10−7 M NTX). Ep: epithelium; St: stroma. Bar = 40 m (derived from [42]). These photomicrographs are of rat peripheral cornea treated with the topical 10−3 M NTX administered q.i.d. × 7 d or controls.