Multiple functions of Na/K-ATPase in dopamine-induced salivation of the Blacklegged tick, Ixodes scapularis.
Multiple functions of Na/K-ATPase in dopamine-induced salivation of the Blacklegged tick, Ixodes scapularis.
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DOI：
10.1038/srep21047
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发表时间：
2016-02-10
影响因子：
4.6
通讯作者：
Park Y
中科院分区：
文献类型：
--
作者：
Kim D;Urban J;Boyle DL;Park Y
蜱虫唾液分泌的控制涉及自分泌多巴胺激活两种多巴胺受体：D1和无脊椎动物特异性D1样多巴胺受体。在这项研究中，我们研究了Na/ k - atp酶作为分泌过程的重要组成部分。Na/ k - atp酶的免疫反应性显示，ⅰ型腺泡中有基底向内折叠的层状细胞，ⅱ型腺泡中有腔间质（上皮）细胞，ⅲ型腺泡中有向管腔开放的迷路状向内折叠结构。瓦巴因（10 μmol l−1）是一种特异性Na/ k - atp酶抑制剂，通过抑制III型腺泡病毒的液体转运来消除多巴胺诱导的唾液分泌。在1 μmol l−1的瓜巴因浓度下，分泌的唾液呈高渗性。这表明乌巴因也抑制了I型腺泡中Na/ k - atp酶的离子吸收功能。多巴胺/瓦巴因不参与蛋白质分泌的激活，而多巴胺诱导的唾液含有组成基础水平的蛋白质。我们假设，在III型和II型腺泡中，多巴胺依赖的初级唾液形成由Na/ k - atp酶介导，随后是位于唾液管近端的I型腺泡中Na/ k - atp酶的多巴胺不依赖的吸收功能。
Control of salivary secretion in ticks involves autocrine dopamine activating two dopamine receptors: D1 and Invertebrate-specific D1-like dopamine receptors. In this study, we investigated Na/K-ATPase as an important component of the secretory process. Immunoreactivity for Na/K-ATPase revealed basal infolding of lamellate cells in type-I, abluminal interstitial (epithelial) cells in type-II, and labyrinth-like infolding structures opening towards the lumen in type-III acini. Ouabain (10 μmol l−1), a specific inhibitor of Na/K-ATPase, abolished dopamine-induced salivary secretion by suppressing fluid transport in type III acini. At 1 μmol l−1, ouabain, the secreted saliva was hyperosmotic. This suggests that ouabain also inhibits an ion resorptive function of Na/K-ATPase in the type I acini. Dopamine/ouabain were not involved in activation of protein secretion, while dopamine-induced saliva contained constitutively basal level of protein. We hypothesize that the dopamine-dependent primary saliva formation, mediated by Na/K-ATPase in type III and type II acini, is followed by a dopamine-independent resorptive function of Na/K-ATPase in type I acini located in the proximal end of the salivary duct.