The absorptive activity of ameloblasts during the maturation of enamel
โ Scribed by Reith, Edward J. ;Cotty, Val F.
- Publisher
- John Wiley and Sons
- Year
- 1967
- Tongue
- English
- Weight
- 907 KB
- Volume
- 157
- Category
- Article
- ISSN
- 0003-276X
No coin nor oath required. For personal study only.
โฆ Synopsis
The activity of ameloblasts during the maturation of enamel was investigated by means of autoradiography. Young rats were given daily injections of radioactive sulfur. Injections were started when the rats were five days old and continued until some of the rats were 12 days old. Developing teeth were removed at different times and prepared for autoradiography.
In every specimen that was examined, silver grains were found over enamel that was adjacent to tall, secretory ameloblasts. These cells have been identiiied as being engaged in matrix formation.
At the end of matrix formation, the tall ameloblasts become structurally reorganized, and the reorganized cells now act on the enamel as it matures. Despite the fact that the animals receive daily injection of labeled sulfur, the silver grains over the maturing enamel decrease and silver grains are observed over the cytoplasm of the shortened ameloblasts.
It is concluded therefore that one of the activities of the reorganized (transporting) ameloblasts is to remove sulfur o r a sulfated compound from the enamel during its maturation.
๐ SIMILAR VOLUMES
A pattern of obliquely oriented bands has been demonstrated at the surface of the maturation zone enamel of freshly dissected rat incisor teeth as they dry. This pattern, of which there is no evidence in the fresh, wet, or completely dry teeth, consists of up to 4 or 5 pale grey, translucent lines s
This study was designed to study the time course of the incorporation of 55Fe into the ameloblasts of maturation in rat incisors. Male Sherman rats (100 k 5 gm) were injected intravenously with 0.9 mCi of 55Fe and sacrificed in pairs by perfusion at various time intervals from 5 min to 7 'The grains