Glycosaminoglycans in embryonic mouse tooth germs. A histochemical analysis.

Glycosaminoglycans (GAG) were localized in embryonic mouse molars by Alcian-blue staining in a critical-electrolyte-concentration (CEC) method (Scott and Dorling, 1965). Sulfated GAG were distinguished from hyaluronate (HA) by combining the binding specificity of Alcian blue and substrate specificity of GAG-lytic enzymes. The stratum reticulum was found to contain a small amount of HA, but no chondroitin sulfate (CS). The amount of HA decreased gradually during odontogenesis. No GAG were detected in the outer and inner dental epithelia. The basement membrane and the predentine were intensely stained, and shown to be rich in HA and CS. The preodontoblastic layer contained small amounts of HA and CS. These decreased progressively during odontogenesis. No GAG was found at the odontoblastic layer. The lower dental papilla contained a constant amount of HA (the major component) and CS.