Lundgren T, Nannmark U, Linde A
Department of Oral Biochemistry, University of Göteborg, Gothenburg, Sweden.
Calcif Tissue Int. 1992 Feb;50(2):134-6. doi: 10.1007/BF00298790.
Ca2+ ion activities and pH were measured in the odontoblast/predentin region of rat incisors by means of the microelectrode technique. In Ringer solution, the apparent resting membrane potential of odontoblasts was determined to be -24 +/- 4 mV (mean +/- SE), whereas the odontoblast intracellular pH was found to be 6.66 +/- 0.02. The values obtained are within the range of other cell types, as measured in similar incubating solutions. The pH in the extracellular predentin was higher than the intracellular pH, 7.00 +/- 0.02. The Ca2+ ion activity in predentin (pCa = 2.94 +/- 0.15) was found to be significantly (P less than 0.001) higher than that in the dental pulp extracellular fluid (pCa = 3.37 +/- 0.14). The 2-3 times higher calcium activity extracellularly in predentin, compared with the dental pulp, implies the existence of some ion-concentrating mechanism across the odontoblast layer in the direction of the mineralization front.
采用微电极技术测量大鼠切牙成牙本质细胞/前期牙本质区域的Ca2+离子活性和pH值。在林格氏液中，成牙本质细胞的表观静息膜电位测定为-24±4 mV（平均值±标准误），而成牙本质细胞内pH值为6.66±0.02。在类似的孵育溶液中测量时，所获得的值在其他细胞类型的范围内。前期牙本质细胞外的pH值高于细胞内pH值，为7.00±0.02。发现前期牙本质中的Ca2+离子活性（pCa = 2.94±0.15）显著高于牙髓细胞外液中的Ca2+离子活性（pCa = 3.37±0.14）（P<0.001）。与牙髓相比，前期牙本质细胞外的钙活性高2-3倍，这意味着在矿化前沿方向上存在某种跨成牙本质细胞层的离子浓缩机制。
