-Abstract-
Growth factors have been reported to be expressed within several tissue
compartments of a developing tooth. Among growth factors, TGF-β1 may play a
crucial role in the tooth development. The aim of this study was to observe the
expression of TGF-β1 in the developing dental tissues of rats. Development of dental
tissues requires orchestration of periodontal ligament cells, were studied to compare the
effects of TGF-β1, PDGF, IGF-I, and EGF on proliferation. Cells obtained from healthy
rat periodontal tissues were cultured on 10% FBS supplemented with the growth factor
alone, and combination at the concentrations of 0.1ng/㎖, 1ng/㎖, and 10ng/㎖. Tritium
thymidine incorporation of the cells was measured after 24h incubation. For
immunohistochemistry, animals aged 14 days were sacrificed and then their maxillary
first molar were removed, fixed, demineralized, and processed inparaffin. The localization
of TGF-β1 in tissues was detected by ABC immunoperoxidase immunostaining using
polyclonal goat anti-rat TGF-β1.
The results are as follows;
1. TGF-β1, PDGF, EGF, and IGF increased the proliferation of PDL cells in that order.
2. TGF-β1 was expressed in the developing alveolr bone, periodontal ligament, and
cementum, whereas it was not expressed in enamel at early stage of the root
development.
3. Cementoblasts and osteoblasts showed a greater immunoreactivity either anti-TGFβ1
than fibroblasts and odontoblasts. Osteocytes in the developing bone revealed a weak
immunoreactivity while ameloblasts did not.
4. As compound to mature bone newly forming bone matrix demonstrated a stronger
immunoreactivity with anti-TGFβ1.
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