Influence of manganese deficiency on the characteristics of proteoglycans of avian epiphyseal growth plate cartilage.

The need for manganese for normal skeletal development appears to be related to its role in proteoglycan biosynthesis. The purpose of this research was to characterize the proteoglycans synthesized under conditions of manganese deficiency. The proteoglycans were extracted from epiphyseal growth plate cartilage and the monomers separated by cesium chloride density gradient centrifugation followed by column chromatography. The proteoglycan monomers from normal cartilage contained primarily (92%) chondroitin sulfate side chains with keratan sulfate being a minor (8%) component. Manganese deficiency reduced the total amount of cartilage proteoglycans. Of the monomers present in deficient cartilage, the majority (75%) were similar to those found in normal cartilage. Cartilage from deficient chicks also contained a second monomer fraction (25%) characterized by a reduced carbohydrate content. Thus, in addition to a reduction in total proteoglycan content, manganese deficiency results in qualitative changes in the proteoglycans present in epiphyseal growth plate cartilage.