The usefulness of rat incisor dentin in evaluating pharmacological effects on mineralization in hard tissues

我们报道了几项实验，显示了使用大鼠门牙本质来检查药物对硬组织矿化的药理学和毒理学影响的优势。采用接触显微放射照相（CMR）和脱矿横切面苏木精染色评价切牙本质的矿化程度。在一些实验中，用去甲状旁腺的大鼠，在门牙本质矿化已经被抑制的情况下，研究药物对牙本质矿化的促进作用。该作用可作为评价各种钙盐、维生素D代谢物、甲状旁腺激素对牙本质矿化作用的指标。我们的实验模型似乎适合在体内对牙本质形成过程中细胞活性的影响进行药理学评估。正常大鼠门牙本质矿化抑制程度可作为评价药物对硬组织毒性的指标之一。为了确定作用部位，如上所述对药物毒性进行了评估，并通过检查血清钙水平、药物对再矿化的理化作用和体外实验结果进行了评估。此外，在去卵巢大鼠骨和牙本质矿化的同时评估中显示了药理学效果。这些结果表明牙本质在研究药物对胶原基质矿化的影响方面是有用的。

We reported several experiments showing the advantages of using rat incisor dentin for examining the pharmacological and toxicological effects of drugs on mineralization in hard tissues. The degree of mineralization in the incisor dentin was evaluated by contact microradiography (CMR) and by the hematoxylin stainability of demineralized transverse sections. In some experiments, parathyroidectomized rats, in which mineralization of the incisor dentin had already been suppressed, were used to examine the promoter action of drugs on the mineralization of dentin. This action could be used as an indicator for evaluating the medicinal effect of various calcium salts, vitamin D metabolites, and parathyroid hormone on dentin mineralization. Our experimental model seemed to be suitable for pharmacologically evaluating effects upon cellular activity in dentin formation, in vivo. The degree of inhibition of mineralization in the incisor dentin of normal rats could be regarded as an indicator for evaluating the toxicity of drugs on hard tissue. To determine the site of action, drug toxicity was evaluated as described above, as well as by examining the serum calcium levels, the physicochemical actions of drugs on remineralization, and findings in vitro. Furthermore, the pharmacological effectiveness on simultaneous evaluation of the mineralization in bone and dentin was shown in ovariectomized rats. These results suggest the usefulness of dentin in studying the effects of drugs on the mineralization of a collagenous matrix.