Synthesis of glucuronoglucans in chicken cartilage cultured in synthetic medium

Cartilaginous femur and tibia rudiments from 10-day-old chick embryos were grown in vitro for 4 days in Parker's solution without protein added, and subsequently fixed and extracted successively with 0-2 N HClO4 at 4 degrees C (fraction A), 5 per cent trichloracetic acid (TCA) at 4 degrees C (fraction B), and 5 per cent TCA at 90 degrees C (fraction C). The residue after extraction was dissolved in 1 N NaOH at room temperature (fraction D). Fraction C containing most of hexuronic acids and aminosugars of the cartilage was used to study the quantitative changes of glucuronoglucans throughout the culture period. The amount of hexuronic acids and aminosugars was increased after 24, 48, 72 and 96 hours of culture. After 96 hours the level of hexuronic acids was twice that found prior to establishing the culture. The increment was statistically significant.