Granule proteins of the dental follicle and stellate reticulum inhibit tooth eruption and eyelid opening in postnatal rats.

Electron-dense granules within cells of the dental follicle and stellate reticulum of rat mandibular molars can be isolated; their major components are 167 and 200 kDa proteins. Injecting these granule proteins into postnatal rats results in a delay of incisor eruption and eyelid separation. These inhibitory effects were most pronounced with the 167 kDa protein (a delay of 3 days in incisor eruption and of 2 days in eyelid opening) and were opposite to the stimulatory effects of epidermal growth factor. Thus, these granules may play an inhibitory part in tooth eruption.