Collagen synthesis by isolated bone cells

摘要: Abstract Bone cells isolated from rat calvaria were cultured on a flat surface, and collagen synthesis was determined by the incorporation of radioactive proline into peptide hydroxyproline. Addition ascorbic acid to incubation medium markedly increased radioactivity hydroxyproline in cold water-soluble -insoluble protein fractions, without increasing peptide-bound or DNA content cell cultures. Stimulation demonstrated with low concentrations (3 μM) directly proportional starting concentration. Hydroxylation that had previously been incorporated stimulated despite puromycin- cycloheximide-induced inhibition synthesis. These results indicate promotes bone stimulating hydroxylation proline-rich peptide. Inhibitors consistently when added pulse-labeled cultures absence acid. The data suggest they prevented dilution radioactive, unhydroxylated precursor non-radioactive precursor, thus providing substrate higher specific activity for hydroxylation.