[Effect of hexosamine derivatives on mesenchymal metabolic processes of in vitro cultured fetal bone explants]

The effects of hexosamine derivatives, glucuronic acid, chondroitin sulfate, and oxyphenbutazone on growth and glycosaminoglycan metabolism of murine fetal bone explants cultured for 6 days in vitro were studied. Glucosamine hydrochloride, glucosamine hydroiodide and glucosamine sulfate (at concentrations of 100 micrograms/ml) caused a significant increase in the growth of the explants; this effect was not due to an increase in cell multiplication, as can be concluded from the DNA content of the explants, but rather to an increase in the glycosaminoglycans in the extracellular cartilage matrix. In addition, the three glucosamine salts induced an increase in the secretion of glycosaminoglycans from the surface of the explants into the culture medium. N-acetylgalactosamine, sodium glucuronide and chondroitin sulfate showed lesser or nonsignificant effects as compared to the glucosamine derivatives or the controls. Galactosamine hydrochloride (100 micrograms/ml) exerted inhibitory actions on the bone explants. Oxyphenbutazone (10 micrograms/ml), also, led to a significant inhibition of the growth and glycosaminoglycan metabolism of the explants without influencing (at this concentration) their DNA content. From the results obtained it is concluded that in the treatment of degenerative joint diseases nonsteroidal antiphlogistics acting similarly to oxyphenbutazone should be used, if at all, as cautiously as possible, whereas drugs with the type of action observed in the three glucosamine derivatives could be expected to exert a beneficial effect.