羟基磷灰石、氢氧化钙对鼠牙髓细胞碱性磷酸酶活性的影响

目的：检测羟基磷灰石和氢氧化钙颗粒对鼠原代牙髓细胞碱性磷酸酶活性的影响。方法：采用０．５％胰酶－０．１％ＥＤＴＡ消化法获取ＳＤ鼠原代牙髓细胞。细胞接种后，分别加入氢氧化钙和羟基磷灰石颗粒（＜５０μｍ），在７ｄ或１４ｄ分别测定鼠原代牙髓细胞的碱性磷酸酶活性。结果：氢氧化钙抑制牙髓细胞碱性磷酸酶活性与其高浓度抑制细胞生长有关；羟基磷灰石具有良好的生物相容性，但其能够显著抑制牙髓细胞碱性磷酸酶的活性，抑制率（０．６ｍｇ／ｍｌ）在７ｄ时为５４．６％，１４ｄ时为４９．０％。结论：羟基磷灰石颗粒的作用可能与牙髓细胞去分化过程有关，两种材料对牙髓细胞的活性存在着不同的作有机制。

The effects of hydroxyapatite or calcium hydroxide on the alkaline phosphatase activity of primary cells of rat pulp

Aim: To examine the alkaline phosphatase activity of primary pulp cells in contact with hydroxyapatite and compare it with the effect of calcium hydroxide. Methods: The primary pulp cells of Sprague-Dawley rats were isolated with 0.5% trypsin-0.1% EDTA, The alkaline phosphatase activity was measured. Results: The alkaline phosphbatase activity and the growth rate of pulp cells were strongly inhibited in the presence of calcium hydroxide. Hydroxyapatite had good biocompitability with various cells,, but the alkaline phosphatase activity of rat pulp cells was significantly inhibited in the presence of hydroxyapatite particles(0.6mg/ml), the inhibition were 54.6% at day 7 and 49.0%at day 14. Conclusions: The effect of hydroxyapatite on the alkaline phosphatase activity may be related to the process that pulp cells de-differentiate into mesenohymal cells. There are different mechanisms between calcium hydroxide and hydroxyapatite during pulp cell differentiation and mineralization.