Molecular Pharmacology, Vol 15, 99-107, Copyright © 1979 by the American Society for Pharmacology and Experimental Therapeutics

Glucocorticoids Decrease Prolyl Hydroxylase Activity without the Cellular Accumulation of Undehydroxylated Collagen

¹ Department of Biochemistry, School of Medicine, University of Vermont, Burlington, Vermont 05401

Cells were isolated from the dermis of control and triamcinolone-treated rats. The triamcinolone-treated cells were 86% viable as determined by trypan blue exclusion. Radioactive proline was added to the cell cultures and total proline incorporation and proteinaceous hydroxyproline synthesis were quantified. The cells isolated from triamcinolone-treated rats incorporated less proline into cellular protein than did control cultures. The amount of proteinaceous hydroxyproline synthesized by cells isolated from steroid-treated rats was decreased to a greater extent than total proline incorporation. The percent of cellular collagen was decreased in steroid-treated cells. Although prolyl hydroxylase activity (EC 1.14.11.2) in the cells isolated from glucocorticoid-treated rats was decreased, the extent of prolyl hydroxylation of total cellular collagen was not decreased. The data indicate that glucocorticoid treatment does not result in the synthesis and subsequent cellular accumulation of underhydroxylated collagen.