Mercury exposure is considered a public health problem due to the generation of toxic effects on human health as a result from environmental and occupational conditions. The inorganic form of mercury (HgCl2) can cause several biological changes in cells and tissues through its cumulative toxic potential, but little has been experimentally proven about the effects of inorganic mercury on salivary glands, an important modulator organ of oral health. This study analyzes the effects of prolonged low dose exposure to HgCl2 on the salivary glands of rats. Adult animals received a dose of 0.375mg/kg/day over a period of 45 days. The parotid and submandibular glands were collected for analysis of mercury levels and evaluation of oxidative stress, histological parameters and immunomodulation for Metallothionein I and II (MT- I/II). In this investigation, biochemical and tissue changes in salivary glands were verified due to mercury levels, causing reduction in antioxidant capacity against peroxyl radicals , with consequent cellular lipid peroxidation and an increase in nitrite levels, volumetric changes and cytoskeletal damage in submandibular glands, with less severe damage to parotid glands. The results also have shown the occurrence of a cytoprotection mechanism due to increased MT-I/II expression, but not enough to avoid the morphology and oxidative damage. This evidence highlights, for the first time, that inorganic mercury is able to alter morphology and oxidative biochemistry in salivary glands when exposed for a long time in low doses.

中文翻译：

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慢性汞暴露引起大鼠唾液腺生物化学和形态变化

由于环境和职业条件对人体健康产生毒害作用，因此汞接触被认为是公共卫生问题。汞的无机形式（HgCl2）可以通过其累积的潜在毒性引起细胞和组织中的几种生物学变化，但是关于汞对唾液腺（一种口腔健康的重要调节器官）的作用的实验研究很少。这项研究分析了长期低剂量暴露于HgCl2对大鼠唾液腺的影响。成年动物在45天内接受0.375mg / kg /天的剂量。收集腮腺和下颌下腺用于汞含量的分析以及金属硫蛋白I和II（MT-I / II）的氧化应激，组织学参数和免疫调节的评估。在这次调查中 唾液腺的生化和组织变化已得到验证，原因是汞含量高，导致抗过氧化自由基的抗氧化剂能力降低，随之而来的细胞脂质过氧化作用和亚硝酸盐含量增加，下颌下腺的体积变化和细胞骨架损害，对腮腺的严重损害较小腺体。结果还显示出由于增加的MT-I / II表达而发生了细胞保护机制，但是不足以避免形态和氧化损伤。该证据首次突显出，长时间低剂量接触无机汞后，唾液腺中的无机汞能够改变其形态和氧化生物化学。随之而来的细胞脂质过氧化作用以及下颌下腺的亚硝酸盐水平，体积变化和细胞骨架损害的增加，对腮腺的损害较轻。结果还显示出由于增加的MT-I / II表达而发生了细胞保护机制，但是不足以避免形态和氧化损伤。该证据首次突显出，长时间低剂量接触无机汞后，唾液腺中的无机汞能够改变其形态和氧化生物化学。随之而来的细胞脂质过氧化作用以及下颌下腺的亚硝酸盐水平，体积变化和细胞骨架损害的增加，对腮腺的损害较轻。结果还显示出由于增加的MT-I / II表达而发生了细胞保护机制，但是不足以避免形态和氧化损伤。该证据首次突显出，长时间低剂量接触无机汞后，唾液腺中的无机汞能够改变其形态和氧化生物化学。但还不足以避免其形态和氧化损伤。该证据首次突显出，长时间低剂量接触无机汞后，唾液腺中的无机汞能够改变其形态和氧化生物化学。但不足以避免其形态和氧化损伤。该证据首次突显出，长时间低剂量接触无机汞后，唾液腺中的无机汞能够改变其形态和氧化生物化学。