短期甲状旁腺素给药可增加小鼠牙本质的形成和显微硬度。

Short-term PTH administration increases dentine apposition and microhardness in mice.

机构信息

Department of Morphology, Division of Histology, Piracicaba Dental School, University of Campinas, Piracicaba, SP, Brazil.

出版信息

Arch Oral Biol. 2012 Oct;57(10):1313-9. doi: 10.1016/j.archoralbio.2012.03.007. Epub 2012 Apr 21.

DOI:10.1016/j.archoralbio.2012.03.007

PMID:22525944

Abstract

OBJECTIVE

The purpose of this study is to investigate the effects of intermittent parathyroid hormone (PTH) administration on the apposition rate and structural features of dentine from mouse incisors.

METHODS

Young male A/J Unib mice were treated daily for 6 and 10 days with 40 μg/kg of hPTH 1-34 or a vehicle. Dentine apposition rates measured by fluorescent labels (tetracycline and calcein) and alkaline phosphatase (ALP) plasma levels were evaluated after 6 days of treatment. Knoop microhardness testing and element content measurements in at.% of calcium (Ca), phosphorus (P), oxygen (O), and magnesium (Mg) in the peritubular and intertubular dentine were performed by Energy Dispersive X-ray (EDX) microanalysis via Scanning Electron Microscopy (SEM) after 10 days of treatment.

RESULTS

Histometric analysis revealed an increase of 5% in the apposition rate of dentine and 25% in the ALP plasma levels in the PTH treated group. In addition, knoop microhardness testing revealed that the animals treated with PTH had a greater microhardness (11%). EDX microanalysis showed that PTH treatment led to increases in P (23%) and Ca (53%) at.% content, as well as the Ca/P ratio (24%) in peritubular dentine. The chemical composition of intertubular dentine did not vary between the groups.

CONCLUSIONS

These findings indicate that intermittent administration of hPTH (1-34) increases apposition and mineralization of the dentine during young mice incisor formation.

摘要

目的

本研究旨在探讨间歇甲状旁腺激素（PTH）给药对小鼠门齿牙本质形成速率和结构特征的影响。

方法

用 40μg/kg 的 hPTH 1-34 或载体每日处理年轻雄性 A/JUnib 小鼠 6 天和 10 天。用荧光标记物（四环素和钙黄绿素）和碱性磷酸酶（ALP）血浆水平测量牙本质形成速率，处理 6 天后进行评估。处理 10 天后，通过扫描电子显微镜（SEM）的能量色散 X 射线（EDX）微分析测量近小管和小管间牙本质中钙（Ca）、磷（P）、氧（O）和镁（Mg）的含量。

结果

组织学分析显示，牙本质形成速率增加了 5%，ALP 血浆水平增加了 25%。此外，努普微硬度测试显示，PTH 处理组的动物具有更大的微硬度（11%）。EDX 微分析表明，PTH 处理导致近小管牙本质中 P（23%）和 Ca（53%）的含量增加，以及 Ca/P 比值（24%）增加。小管间牙本质的化学成分在两组之间没有差异。