Calcitonin stimulates proteoglycan formation in human osteoarthritic cartilage. Human OA articular cartilage explants were cultured with or without doses of salmon calcitonin, and on day 16 pulsed with 5 μCi 35SO4 for 24 hours. The proteoglycans were extracted and the incorporation of 35SO4 were followed by liquid scitillation counting. Insulin-like growth factor (IGF) was used as a positive control to induce formation in articular cartilage. The bars represent the mean value of count pr. minute, cpm, from 6-replicates and the indivdual values were adjusted for the amount of cultured cartilage. The errorbars are the standard error of mean, SEM. The asterisks symbolize the levels of statistical difference to the vehicle control, * P < 0.05, ***P < 0.001.