The mechanism of immature permanent teeth's apex closure

从牛牙胚中去除牙本质，经胶原酶处理后分离细胞内基质囊泡部分，测定基质囊泡的碱性磷酸酶、蛋白水解酶和乳酸脱氢酶活性。在牙本质中发现含有碱性磷酸酶、金属蛋白酶和乳酸脱氢酶的基质小泡。我们还发现了高密度的基质泡泡样囊泡。它们还含有碱性磷酸酶和乳酸脱氢酶，但不含金属蛋白酶。

The dentin was removed from bovine tooth germs, followed by the separation of the intracellular matrix vesicles fraction after collagenase treatment.Alkaline phosphatase activity, protease activity, and lactate dehydrogenase activity were assayed for the marker enzyme of matrix vesicles. Matrix vesicles containing alkaline phosphatase, metalloprotease, and lactate dehydrogenase were found in the dentin. We also found matrix vesicle-like vesicles with a high density. Those also contained alkaline phosphatase and lactate dehydrogenase, but not metalloprotease.