Effects of heavy metals on dental hard tissues formation and pulpal polyamines.

虽然已知一些重金属会干扰硬组织的形成，但确切的机制仍不清楚。在这些研究中，研究了重金属镉对大鼠切牙牙髓中多胺和二胺代谢的影响。牙髓多胺和二胺的层析图谱与肝脏的不同，牙髓多胺的特殊图谱可能与牙髓的独特组织学有关。大鼠切牙牙髓中腐胺含量有明显的昼夜变化，在其他实验中观察到大鼠切牙牙髓中腐胺的昼夜节律主要是由摄食引起的。大鼠切牙牙髓中腐胺和多胺含量随年龄增长而减少。提示年轻大鼠切牙牙髓细胞增殖活跃，牙髓细胞的生命周期随年龄增长而延长。本文研究了镉对大鼠切牙牙髓多胺影响的性别差异。这是很有趣的，因为大鼠牙齿组织对镉的性别差异。体内镉对大鼠切牙牙髓中二胺和多胺含量的影响存在性别差异，但体外培养牙髓细胞对镉的反应没有性别差异。本文研究了秋水仙碱对大鼠骨髓组织中组胺和腐胺含量的影响，发现组胺含量在时程研究中表现为失语性变化。本文研究了脂多糖和硫代乙酰胺对大鼠切牙牙髓组织中组氨酸和鸟氨酸脱羧酶活性的影响。组氨酸脱羧酶活性容易被这些药物诱导。

Although some heavy metals are known to cause disturbances of hard tissues formation, the precise mechanisms remains obscure. In these studies, effects of heavy metal, cadmium, on the polyamines and diamines metabolisms in rat incisor pulp were investigated.1. The chromatographic patterns of dental pulpal polyamines and diamines are different from those of hepatic's. The specific patterns of pulpal polyamines may be due to the unique histology of pulp. The putrescine content in the rat incisor pulp showed the diurnal changes and, in other experiment, it was observed the diurnal rhythm in the pulpal putrescine in rat incisor is induced by feeding mainly. Putrscine and polyamines in rat incisor pulp decreased with age. This result may indicates that the cellular proliferation of rat incisor pulp occurs actively in younger rats and that the duration of life cycle of pulp cells increase with age.2. The sex difference in the cadmium effect on pulpal polyamines in rat incisor were studied. This is of interest because of the sex difference in rat dental tissues to cadmium. The sex difference were observed in cadmium effects on diamines and polyamines contents in rat incisor pulp in vivo, but, in vitro experiment using cultured pulp cells, sex difference was not observed in the response of cells to cadmium.3. The colchicine effect on the pulpal histamine and putrescine contents in rat bone marrow was studied and histamine content showed diaphasic changes in time course study. The effects of LPS and thioacetamide on histidine- and ornithine-decarboxylases activities in rat incisor pulp were studied. Histidine decarboxylase activity was easily induced by these drugs.