CONCISE REPORT Effect of pulsed electromagnetic fields on proteoglycan biosynthesis of articular cartilage is age dependent

Objective: To investigate the effects of a pulsed electromag-netic field (EMF) on articular cartilage matrix biosynthesis with regard to age and cartilage damage using a matrix depleted cartilage explant model. Methods: Cartilage explants were obtained from metacarpo-phalangeal joints of calves and adult cows. After depletion of the extracellular matrix by trypsin digestion, samples were maintained in serum-free basal medium with and without the addition of interleukin 1b (IL1b). Half the samples were subjected to an EMF for 24 minutes daily; the other half were left untreated. Undigested and untreated explants served as negative controls. After 7 days, biosynthesis of matrix macromolecules was assessed by [35S]sulphate incorpora-tion and values were normalised to hydroxyproline content. Results: The EMF increased matrix macromolecule synthesi