Administration of pharmacological doses of glucocorticoids, a class of widely clinically used anti-inflammatory drugs, to experimental animals and man results in diminished growth of normal and inflammed connective tissues. A general wasting of connective tissue occurs. Furthermore, the content of newly-synthesized collagen of skin is selectively decreased. Previous studies from this laboratory indicate that the selective decrease in collagen content results from a specific decrease in collagen polypeptide synthesis. The amount of newly synthesized dermal collagen and ribosomal collagen peptides are decreased to a greater extent than noncollagen proteins. Future studies will determine the molecular mechanism of this selective decrease of collagen synthesis in normal rat and human fibroblasts. We have already demonstrated that glucocorticoid selectively decreases collagen synthesis in primary and cultured rat skin fibroblasts and human fibroblasts. The collagen synthetic activity will be determined. Collagen mRNA will be purified from collagen synthesizing polysomes which have been isolated from fibroblasts by immunoprecipitation, or directly from fibroblasts by poly U sepharose chromatography and density gradient fractionation. Complimentary DNA (cDNA) to collagen mRNA will be synthesized using AMV RNA-directed DNA polymerase. The cDNA will then be used in RNA excess hybridization experiments to determine the gene dosage in glucocorticoid treated fibroblasts. Furthermore, possible effects of glucocorticoids on the rates and quantities of type I and type III collagens will be determined.