Alterations in the synthesis and deposition of collagen occur in several disease states. In that these changes may represent alterations in the cells normal control mechanisms the long range goal of this project is to add to our understanding of what these control mechanisms may be and how they are altered. The immediate objectives are: (l) to characterize the effects of growth conditions known to alter the amount of collagen synthesis. Hence we will focus on the effects of medium hypertonicity (high NaCl), (2) examine the changes leading to a shift of collagen types induced by adding the nucleotide analog 5 bromo 2 deoxyuridine to the growth medium of cultured chondrocytes. The steps in collagen synthesis which will be examined include the messenger RNA content, translational efficiency of the messenger RNA, and post-translational modifications of the collagen chains including secretion.