Centeno V A, Fontanetti P A, Interlandi V, Ponce R H, Gallará R V
Department of Biological Chemistry, School of Dentistry, National University of Córdoba, Córdoba, Argentina.
Department of Biological Chemistry, School of Dentistry, National University of Córdoba, Córdoba, Argentina.
Arch Oral Biol. 2015 Feb;60(2):313-9. doi: 10.1016/j.archoralbio.2014.11.003. Epub 2014 Nov 11.
Connexins (Cxs) are important to control growth and cell differentiation of dental tissues. The aim of the present study was to assess the impact of chronic exposure to sodium fluoride (NaF) on Cxs expression and alkaline phosphatase (ALP) activity in dental pulp, and on morphometric parameters of adult rat mandible and incisors.
Three groups of male Wistar rats (22 days-old) were given water containing: (a) 0.3 mg/L (Control), (b) 10 mg/L and (c) 50 mg/L of NaF for eight weeks. Incisor pulp homogenates were prepared for determination of Cx32, Cx43 and Cx45 gene expression, using semi-quantitative RT-PCR, and of ALP activity. Morphometric parameters of mandible and incisors were determined on radiographs.
Cx43 gene expression increased with exposure to NaF in a dose-dependent manner. Cx32 mRNA levels were higher than controls in the 10mg/L NaF group only; Cx45 mRNA levels were lower in groups given 10 and 50mg/L of NaF than in controls. ALP activity was higher in both high-NaF dose groups compared to the control group (p<0.05). Lower incisor diameter was lower in the 50 mg/L NaF than in the control group (p<0.01). None of the mandibular growth parameters were affected by NaF treatment.
Our results showed that fluorotic alterations in rat incisor were associated with increased Cx43 expression and ALP activity, as well as with changes in the expression pattern of different Cxs in pulp tissue. The observed changes may have a stimulating effect on dentin mineralization.
连接蛋白（Cxs）对控制牙组织的生长和细胞分化很重要。本研究的目的是评估长期暴露于氟化钠（NaF）对牙髓中Cxs表达和碱性磷酸酶（ALP）活性的影响，以及对成年大鼠下颌骨和切牙形态计量参数的影响。
将三组雄性Wistar大鼠（22日龄）给予含以下物质的水：（a）0.3mg/L（对照组）、（b）10mg/L和（c）50mg/L的NaF，持续8周。制备切牙髓匀浆，采用半定量逆转录聚合酶链反应（RT-PCR）测定Cx32、Cx43和Cx45基因表达以及ALP活性。在X线片上测定下颌骨和切牙的形态计量参数。
Cx43基因表达随NaF暴露呈剂量依赖性增加。仅在10mg/L NaF组中，Cx32 mRNA水平高于对照组；给予10mg/L和50mg/L NaF组的Cx45 mRNA水平低于对照组。与对照组相比，两个高NaF剂量组的ALP活性均较高（p<0.05）。50mg/L NaF组的下切牙直径低于对照组（p<0.01）。NaF处理未影响任何下颌骨生长参数。
我们的结果表明，大鼠切牙的氟中毒改变与Cx43表达增加、ALP活性增加以及牙髓组织中不同Cxs表达模式的变化有关。观察到的变化可能对牙本质矿化有刺激作用。
