Proteoglycans of rabbit corneas with nonperforating wounds

Document Type

Article

Publication Date

1-1-1989

Abstract

Rabbit corneal proteoglycans were labeled by intrastromal injection of 3H-glucosamine and 35S-sulfate 1 and 2 weeks after partial-thickness radial scalpel incisions. Proteoglycans were extracted with guanidine-HCl and purified by ion exchange chromatography. Wounding caused a marked decrease in the total incorporation of labeled precursors into proteoglycans. The labeled proteoglycans were more readily extracted with guanidine-HCl after wounding. Labeled proteoglycans from wounded corneas had a larger molecular size on gel filtration chromatography than did proteoglycans from control corneas, a result of an increased amount of keratan sulfate in the large molecular size fractions. Analysis of labeled glycosaminoglycan (GAG) from guanidine-extracted proteoglycans and from the corneal tissue after guanidine-HCl extraction showed an increase in the relative amount of heparan sulfate and keratan sulfate after wounding, and a decrease in relative amount of dermatan sulfate. The 35S:3H ratio of heparan and dermatan sulfates increased after wounding, and that of keratan sulfate decreased, suggesting changes in sulfation. Degradation of labeled dermatan sulfate with hyaluronidase and with periodate revealed a 2-fold increase in iduronic acid content and 2-4-fold increase in hyaluronidase-resistant dermatan sulfate in the wound corneas. Reduction n proteoglycan content, reduced sulfation of keratan sulfate, and accumulation of a high-sulfate, high-iduronic acid dermatan sulfate re previously reported properties of proteoglycan in scar tissue from perforating corneal wounds. Demonstration of these properties in proteoglycan after wounds similar to radial keratotomy incisions suggests that deposition of scar tissue can result from wounds which do not damage Descemet's membrane.

Publication Source (Journal or Book title)

Investigative Ophthalmology and Visual Science

First Page

435

Last Page

442

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