Expression and cellular localizaion of melatonin-synthesizing enzymes in rat and human salivary glands
Expression and cellular localizaion of melatonin-synthesizing enzymes in rat and human salivary glands
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DOI：
10.1007/s00418-011-0800-8
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发表时间：
2011-04-01
影响因子：
2.3
通讯作者：
Satomura, Kazuhito
中科院分区：
文献类型：
--
作者：
Shimozuma, Masashi;Tokuyama, Reiko;Satomura, Kazuhito
褪黑激素于 1958 年被发现，主要由松果体在夜间分泌。其分泌受环境的光/暗循环控制。褪黑素也在松果外各种器官、组织和细胞中产生和分泌，其合成酶芳基烷基胺N-乙酰转移酶(AANAT)在松果外各种器官、组织和细胞中表达。最近有报道称唾液中存在褪黑激素，但尚不清楚褪黑激素是在哪里合成的、是否分泌到唾液中以及在唾液中可能具有什么功能。本研究旨在调查褪黑激素的合成位置以及是否由唾液腺分泌到唾液中。我们对大鼠腮腺、颌下腺和舌下腺中 AANAT 的表达以及人颌下腺中 AANAT 和羟基吲哚-O-甲基转移酶 (HIOMT) 的表达进行了免疫组织化学分析。我们通过定量逆转录聚合酶链反应评估了大鼠颌下腺中 AANAT 和 HIOMT mRNA 的表达。结果，我们观察到大鼠唾液腺横纹管上皮细胞中AANAT的表达以及人颌下腺横纹管上皮细胞中AANAT、HIOMT和褪黑激素的表达。此外，我们还证实了最强效的褪黑激素受体——褪黑激素1a受体在大鼠颊粘膜中的表达。我们的研究结果表明，褪黑激素可能由唾液腺直接产生并分泌到唾液中，并且它可能在口腔中发挥一些生理作用。
Melatonin, discovered in 1958, is secreted by the pineal gland primarily during the night. Its secretion is controlled by the light/dark cycle of the environment. Melatonin is also produced in and secreted by various extrapineal organs, tissues and cells and its synthesizing enzyme arylalkylamine N-acetyltransferase (AANAT) is expressed in various extrapineal organs, tissues and cells. Recently, it was reported that melatonin is present in saliva, but it is not certain where melatonin was synthesized and whether it was secreted into saliva and what function it may have in saliva. The present study was performed to investigate where melatonin was synthesized and whether it was secreted by salivary glands into saliva. We performed immunohistochemical analysis of the expression of AANAT in rat parotid, submandibular and sublingual glands and the expression of both AANAT and hydroxyindole-O-methyltransferase (HIOMT) in human submandibular glands. We evaluated the expression of AANAT and HIOMT mRNA in rat submandibular glands by quantitative reverse transcription-polymerase chain reaction. As a result, we observed expression of AANAT in epithelial cells of striated ducts in rat salivary glands and expression of AANAT, HIOMT and melatonin in epithelial cells of striated ducts in human submandibular glands. In addition, we also confirmed the expression of the most potent melatonin receptor, melatonin 1a receptor, in rat buccal mucosa. Our findings suggest that melatonin might be produced and secreted by salivary glands directly into saliva and that it might play some physiological role in the oral cavity.