[Effect of insulin on cartilage differentiation in vitro]

A consistent chondrogenesis takes place in high-density microcultures derived from bud mesenchymal cells of 4-day-old chicken embryos in a serum-supplemented medium. In serum-free medium DNA level and uronic acid content in the cultures were low, as well as the 35SO4 uptake and release, and only a small mass of cartilage was formed. With the addition of 0.025-10 micrograms/ml insulin to serum-free medium the uronic acid and DNA content in the cultures increased considerably in a dose-dependent way. The intensity of 35SO4 uptake and release exceeded the values measured in serum-containing medium, more cartilage tissue was formed in them also in a dose-dependent manner. With the use of 20-80 micrograms/ml insulin, the increment in DNA content proved to decrease, and with the use of 80 micrograms/ml insulin the uronic acid content and the cartilage mass decreased to a greater extent than in the case of lover doses.