Visualization of glycosaminoglycans in rat incisor extracellular matrix using a hyaluronidase-gold complex

The enzyme-gold technique was used on dental tissues. Hyaluronidase was complexed with gold, and ultrathin sections of rat incisors were incubated with the hyaluronidase-gold complex to localize chondroitin-sulphate and hyaluronic acid at the ultrastructural level. The hyaluronidase-gold complex was found in predentine and dentine, especially at the mineralization front, in interglobular spaces and around dentinal canaliculi. The very young enamel was labelled, but not the later stages of formation. This method allowed a very precise localization of hyaluronic acid and/or chondroitin sulphate in rat incisors extracellular matrices. These findings support the important role of glycosaminoglycans in dentine mineralization.