Abstract
In the basal odontogenic zone of the mandibular incisor of the rat the cytological evidence of the toxicity of 40 mg cyclophosphamide per kg, 24 hours following a single intraperitoneal injection, was confined to the proliferating mesenchyme. Localised loss of precursors of odontoblasts cessation of basal odontogenesis and acellularity of the related part of the pulp ensured. The cells of the internal enamel epithelium bordering this region did not differentiate into ameloblasts and appeared atrophic. Upon recovery of the proliferating mesenchymal cell population odontogenesis was resumed basal to the zone of the cytotoxic injury. Pulpal connective tissue generating irregular dentine advanced from the reconstituted basal zone into the area of pulpal acellularity. This was followed by the differentiation of the peripheral stunted cells of the internal enamel epithelium into ameloblasts and locally delayed resumption of amelogenesis. These observations appear to offer direct evidence of epithelial-mesenchymal interdependence in situ.
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- Adatia A. K. Cytotoxicity of cyclophosphamide in the rat incisor. Br J Cancer. 1975 Aug;32(2):208–218. doi: 10.1038/bjc.1975.151. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Adatia A. K. The effects of cyclophosphamide on odontogenesis in the rat. Arch Oral Biol. 1975 Feb;20(2):141–144. doi: 10.1016/0003-9969(75)90170-3. [DOI] [PubMed] [Google Scholar]
- Glasstone S. The Development of Tooth Germs in vitro. J Anat. 1936 Jan;70(Pt 2):260–266.3. [PMC free article] [PubMed] [Google Scholar]
- Katchburian E., Burgess A. M. Fine structure of contacts between ameloblasts and odontoblasts in the rat tooth germ. Arch Oral Biol. 1977;22(8-9):551–553. doi: 10.1016/0003-9969(77)90054-1. [DOI] [PubMed] [Google Scholar]
- MARSLAND E. A. A histological investigation of amelogenesis in rats. I. Matrix formation. Br Dent J. 1951 Nov 20;91(10):251–261. [PubMed] [Google Scholar]
- Robins M. W. The proliferation of pulp cells in rat incisors. Arch Oral Biol. 1967 Apr;12(4):487–501. doi: 10.1016/0003-9969(67)90023-4. [DOI] [PubMed] [Google Scholar]
- Slavkin H. C., Beierle J., Bavetta L. A. Odontogenesis: cell-cell interactions in vitro. Nature. 1968 Jan 20;217(5125):269–270. doi: 10.1038/217269a0. [DOI] [PubMed] [Google Scholar]
- Slavkin H. C., Flores P., Bringas P., Bavetta L. A. Epithelial-mesenchymal interactions during odontogenesis. I. Isolation of several intercellular matrix low molecular weight methylated RNAs. Dev Biol. 1970 Oct;23(2):276–296. doi: 10.1016/0012-1606(70)90099-0. [DOI] [PubMed] [Google Scholar]
- Starkey W. E. Continuous growth in the teeth of rabbits surveyed with tritiated thymidine and tritiated glycine. Br Dent J. 1967 Jul 18;123(2):73–83. [PubMed] [Google Scholar]