Autoradiographic visualization of glycoproteins and glycosaminoglycans in the epithelio-mesenchymal interface of developing mouse tooth germ.

The turnover of basement membrane macromolecules during tooth morphogenesis and odontoblast differentiation was examined by light microscopic autoradiography using 3H-fucose, 35S-sulfate and 3H-glucosamine. Marked incorporation into the basement membrane was found throughout the progressive development. Pulse-chase experiments and prelabeling of tissue components indicated that glycoproteins and glycosaminoglycans in the dental basement membrane are mainly derived from the enamel epithelium. During odontoblast differentiation, incorporation was increased at the epitheliomesenchymal interface at the site of differentiating mesenchymal cells. From these sites the label also disappeared rapidly. This suggests that the active remodeling of extracellular matrix is related to odontoblast differentiation.