Immunoelectron microscopic localization of dentin gamma-carboxyglutamic acid-containing proteins in differentiating rat odontoblasts.

The intracellular synthesis of the dentin-gamma-carboxyglutamic acid-containing proteins (DGPs) by rat odontoblasts was investigated at the electron microscopic level using a sensitive pre-embedding immunoperoxidase technique. The DGPs were detected in the rough endoplasmic reticulum and secretory vesicles, but not in the Golgi apparatus of the odontoblasts, while dentin matrix is not yet reactive. These results suggest that the DGPs synthesis is independent of mineral deposition.