In vitro effect of carboxyl-terminal parathyroid hormone peptide [53-84] in mouse tooth germ

• Published in: Japanese Journal of Pharmacology 1998, Vol.76 (suppl.1), p.198-198
• Main Authors: Takahiro Tsuboi, Toshimitsu Takeuchi, Akifumi Togari
• Format: Article
• Language: Japanese
• ISSN: 0021-5198

Cultivation of tooth germ in the bell stage is well known to be a good experimental system for studing the differentiation of the tooth-forming cells as well as their matrix secretion. In the present study, we examined the biological activity of carboxyl-terminal parathyroid hormone peptide [53-84] (PTH [53-84]) and amino-terminal peptide [1-34] (PTH [1-34]) during cultivation of the lower molar tooth germ from mouse embryos. PTH[1-34] increased alkaline phosphatase activity at the early developmental stage under the present culture condition (early bell stage to advance bell stage), and decreased it at the late developmental stage of tooth germ (advance bell stage to late bell stage). On the other hand, PTH[53-84] decreased alkaline phosphatase activity at the early developmental stage, and increased it at the late developmental stage. Thus, both PTH fragments had distinct effects on tooth development. The effects of the PTH fragments were confirmed by histological observation which shows marked effects of these peptides on the formation of dentine and enamel. These results indicated that PTH[53-84] has biological activity in tooth germ, and the action of PTH[53-84] is opposite to the action of PTH[1-34]. Furthmore, specific actions of PTH fragments were involved in modulating the cAMP and Ca^2+ system.