Factor(s) for mesio-distal/bucco-lingual determination during tooth development : asymmetrical distribution of calcium signals in the tooth germ

为了阐明在形态牙齿发育中决定颊舌向近远中轴不对称的因素(S)，我们研究了组成牙胚的细胞内钙离子浓度的空间不对称分布模式。位于牙胚近中侧的细胞群细胞内钙离子浓度高于牙胚的其他部位。用上皮生长因子刺激牙胚后，位于牙胚近中侧的细胞组细胞内钙离子浓度一过性升高。结果表明，在牙齿发育过程中，通过瞬时受体电位(Trp)P2通道的细胞内高钙离子浓度的不对称分布决定了牙胚的近中侧。

To clarify the factor(s) in determination of bucco-lingual asymmetry against mesio-distal axis in morphological tooth development, we examined the spatial asymmetrical distribution pattern of intracellular Ca^<2+> concentration in the cells composed the tooth germ. Group of cells located in the mesial side of tooth germ had high intracellular Ca^<2+> concentration, compared with other areas in the tooth germ. Following stimulation of tooth germ with epithelial growth factor, transient increase in the intracellular Ca^<2+> concentration was observed in the group of cells located in the mesial side of tooth germ. The results indicate that, during tooth development, asymmetrical distribution high intracellular Ca^<2+> concentration in the group of cells via transient receptor potential (TRP) P2 (TRPP2) channels determines mesial side of tooth germ.