[Inhibition of Corneal Metabolism by Glucocorticosteroids. An in Vitro Study (author's Transl)]?14Hemmung Des Hornhautstoffwechals Durch Glukocorticosteroide. Eine in Vitro Studie

Cortisone and its derivates demonstrates influence to the metabolism of connective tissue. In this in vitro-study the action of water soluble Dexamethason (Schering) to corneal tissue is quantitatively determined. Incorporation of radioactive sulfate into the glycosaminoglycanes and the sulfate-hexosamine-quotient of keratansulfate and chondroitinsulfate is pointed out. 1. A 2 times 10-7 M Dexamethason-concentration and 6 hours incubation time causes reducing of sulfate incorporation in the case of keratansulfate (I) about 94 per cent and chondroitinsulfate (II) about 89 percent compared to nontreated control. Increasing concentration of Dexamethason leads the inhibition of sulfate incorporation to 66 per cent (I) and 63 per cent (II) respectively. Removing the epithelium from the stroma before incubation the Dexamethason concentration and 6 h incubation time only 84 percent and 80 per cent radioactive sulfate is found in keratansulfate and chondroitinsulfate. An increasing Dexamethason concentration leads to inhibition of 55 per cent (I) and 46 per cent (II) respectively. 2. A comparable inhibition of sulfate incorporation is demonstrated with constant Dexamethason concentration and variable duration of incubation. A 1 hour incubation reduced incorporation of sulfate to 89 per cent for keratansulfate and 81 per cent for chondroitinsulfate. The 24 hours incubation inhibits incorporation to 69 per cent (I) and 65 per cent (II) respectively.