Glycosaminoglycan metabolism of cultured fibroblasts from bovine vitreous.

Glycosaminoglycan metabolism of cultured vitreal cells of bovine origin was investigated with the following results: Cultured vitreal cells distributed the synthesized macromolecules after [35S] sulfate incorporation into the culture medium (extracellular pool), the membrane-bound proteoglycans (pericellular pool), and within the cells (intraocular pool). No extracellular plateau was reached after 3 days; the pericellular and intracellular pools showed a steady state of radioactivity after 48 and 24 h, respectively. Pulse-chase experiments exhibited a rapid turnover of intracellular polysaccharides and a slower metabolism of pericellular polymers. Pinocytosis, adsorption and degradation of vitreal and corneal cell secretion by vitreal cells were observed to a comparable extent. Chondroitin sulfate isomers and heparan sulfate could be detected in minor proportions. The relevance of glycosaminoglycan metabolism in the replacement of cultured vitreal cells into the vitreous cavity is discussed.