A study of the Calcification by matrix vesicles in closure of immature teeth

基质囊泡是一种细胞外细胞器，它在钙化组织的细胞外基质中启动矿化。从胎牛牙本质中提取基质囊泡，经胶原酶消化和差速离心，进行蔗糖-密度梯度离心。本研究以碱性磷酸酶（ALP）、蛋白酶活性乳酸脱氢酶（LDH）和蛋白酶活性来评价基质囊泡。我们在胎牛牙本质中不仅发现了基质小泡，还发现了无蛋白酶的基质小泡样小泡。通过添加Co<2+>, A1<2+>, Zn<2+>, Mg<2+>， o-邻菲罗啉抑制后的蛋白酶活性恢复。这些结果表明，牙本质基质囊泡中的蛋白酶是一种金属蛋白酶。

Matrix vesicles are extracellular organelles that initiate mineralization in the extracellular that initiate mineralization in the extracellular matrix of carious calcifying tissues. The matrix vesicles fractions from the dentin of fetal bovine, obtained by collagenase digestion and differential centrifugation, were subjected to sucrose-density-gradient centrifugation.In this report, we investigated the enzymes alkaline phosphates activity( ALP), protease activity lactate dehydrogenase(LDH) and protease to evaluate the matrix vesicles. We found not only matrix vesicles but also matrix vesicle like vesicles without protease in the dentin of fetal bovine. Protease activity after inhibition with o-phenanthroline was restored by the addition of Co<2+>, A1<2+>, Zn<2+>, Mg<2+>,. These results show that the protease in the matrix vesicles in the dentin is a metalloprotease.