Differentiation of cartilage and bone from common germinal cells. II. Inhibition of chondrogenesis induced by -aminoproprionitrile.

Abstract

Injection into chick embryos incubated for nine days, of β-aminopropionitrile (BAPN) at doses above 0.312 mg/embryo prevented the formation of the cartilage normally present on the membrane bones from the eleventh day of incubation onwards. The histogenesis of this inhibition is described. BAPN increased the proportion of soluble collagen without altering total collagen synthesis and decreased the synthesis of hexosamine-containing acid mucopolysaccharides within the membrane bones. The relationship between cross-linking of collagen, collagen solubility, synthesis of acid mucopolysaccharides and mechanical stimulation (the extrinsic factor initiating chondrogenesis in this system) in the formation of cartilage from bipotential germinal cells on the membrane bones is discussed.