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Contribution of paracellular transport to fluid secretion of the salivary gland.

细胞旁运输对唾液腺液体分泌的贡献。

基本信息

批准号：
16590172
负责人：
MURAKAMI Masataka
金额：
$ 2.3万
依托单位：
National institute for physiological sciences
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2004
资助国家：
日本
起止时间：
2004 至 2005
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-16590172/
关键词：
salivary gland paracellular transport intracellular cAMP Intracellular Ca fluoroescent dye cytoskelton aquaporin albumin aquaprin

项目摘要

The primary saliva is a mixture of secretes both via transcellular and paracellular pathways. This project was designed to clarify the control mechanisms for the paracellular transport. The following results were obtained during the project term.i)Osmolarity changes created by sucrose during the perfusion of isolated rat submandibular glands (SMG) in vitro show that secretion rates alter much more than predicted by the theory of osmotic fluid production. However, these are in accord with a theory involving AQP5 control of paracellular fluid transfer. The changes in transport rate can be predicted with parameters determined earlier for this gland and a quantitative model of the SMG system is presented involving an osmosensor function for AQP5 at the apical membrane. Experiments were performed with SMG from genetically selected rats that have very low levels of AQP5 as determined by Western blotting. The fluid secretion and behavior after osmolarity changes were similar to normal. We sug … More gest that the feedback control involving AQP5 still can operate even at low levels and may probably involve a greater amplification by other elements of the signalling system. While, retrograde injection of Hg ions into the duct to partially inhibit AQP5 lead to a concentration-dependent reduction in flow rates but reduction of fluid secretion after hyper osmotic shock was to that expected for an osmotically equilibrating system. The results indicate that fluid production in the SMG is not osmotic in the steady-state but involves a feedback loop under control of AQP5 acting as an osmosensor.ii)Morphological basis for control of paracellular transport was examined by electron microscope observation of the deep-etching of the rapid frozen samples from isolated perfused rat submandibular gland both in the resting and stimulated perfusion with carbachol/isoproterenol. The integrated proteins which form the tight junction, were connected with deeper actin fibers via the short and fine fibers. Simultaneous stimulation of muscarinic and alpha adrenergic receptors increases both cytosolic Ca and camp and increases the permeability of paracellular route, as revealed by increased permeation of fluorescent dye. During such stimulation the strand of junctional particles changed their order and the strand was expanded toward the basal direction. The submembranous bundles of actin filaments beneath the basolateral membrane and tight junction became dense. The observation indicates that the dynamic structural change of actin filaments could vibrate the distribution of junctional particles, thus may increase the paracellular permeability.iii)Mercurial inhibition of aquaporin was examined functionally and morphologically by retrograde-injection of merculic chloride. From 1 microM to 10 microM of Hg the fluid secretion started to be inhibited in the isolated perfused rat submandibular gland, but no morphological change was observed by High resolution SEM. Whereas further concentration induced fine wrinkles on the surface of intercellular canaluculi.iv)To examine the molecular modulation of large molecule during the passage of paracellular route, the experimental system was set using bovine serum albumine. Less

原发唾液是通过跨细胞和细胞旁途径分泌的混合物。该项目旨在阐明旁细胞运输的控制机制。在项目期间获得了以下结果。i)在体外灌注离体大鼠颌下腺（SMG）期间蔗糖产生的渗透压变化表明，分泌率的变化比渗透液产生理论预测的要大得多。然而，这些都符合涉及 AQP5 控制细胞旁液体转移的理论。运输速率的变化可以通过之前为该腺体确定的参数来预测，并且提出了 SMG 系统的定量模型，涉及顶膜 AQP5 的渗透传感器功能。实验使用来自经过基因筛选的大鼠的 SMG 进行，根据蛋白质印迹法测定，这些大鼠的 AQP5 水平非常低。渗透压变化后的液体分泌和行为与正常相似。我们建议，涉及 AQP5 的反馈控制即使在低水平下仍然可以运行，并且可能涉及信号系统其他元件的更大放大。同时，将汞离子逆行注射到导管中以部分抑制 AQP5 会导致流速呈浓度依赖性降低，但高渗透压休克后液体分泌的减少与渗透平衡系统预期的减少相同。结果表明，SMG 中的液体产生在稳态下不是渗透性的，而是涉及作为渗透传感器的 AQP5 控制下的反馈环路。卡巴胆碱/异丙肾上腺素。形成紧密连接的整合蛋白通过短纤维和细纤维与更深的肌动蛋白纤维连接。同时刺激毒蕈碱和α肾上腺素能受体会增加胞质Ca2+和Camp，并增加细胞旁途径的通透性，如荧光染料渗透性增加所揭示的。在这种刺激过程中，连接颗粒链改变了它们的顺序，并且链向基础方向扩展。基底外侧膜和紧密连接下方的肌动蛋白丝的膜下束变得致密。观察结果表明，肌动蛋白丝的动态结构变化可以振动连接颗粒的分布，从而可能增加细胞旁通透性。iii)通过逆行注射氯化汞，从功能和形态上检测汞对水通道蛋白的抑制作用。从 1 µM 到 10 µM Hg，离体灌注大鼠颌下腺中的液体分泌开始受到抑制，但高分辨率 SEM 未观察到形态变化。而进一步浓缩会在细胞间小管表面引起细皱纹。iv)为了检查大分子在旁细胞途径通过过程中的分子调节，使用牛血清白蛋白设置了实验系统。较少的

项目成果

期刊论文数量（51）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

生理現象と高分子排除体積効果(Excluded Volume Effect)-高分子活動係数(I)

生理现象和排除体积效应-聚合物活性系数（I）

DOI：
发表时间：
2006
期刊：
日本生理学雑誌 68.1
影响因子：
0
作者：
Urakawa S.;et al.;曾我美勝
通讯作者：
曾我美勝

Sequence of forebrain activation induced by Intraventricular injection of hypertonic NaCl detected by Mn^<2+> contrasted T_1-weighted MRI.

Mn^2对比T_1加权MRI检测脑室内注射高渗氯化钠诱导的前脑激活序列。

DOI：
发表时间：
2004
期刊：
Autonomic Neuroscience 113
影响因子：
0
作者：
Morita H;Ogino T;et al.
通讯作者：
et al.

Physiological phenomenon and excluded volume effect by large molecules : Activity coefficients of large molecules (part 1) in Japanese.

大分子的生理现象和排除体积效应：日语中的大分子活性系数（第 1 部分）。

DOI：
发表时间：
2006
期刊：
J Physiol Soc Japan 68(1)
影响因子：
0
作者：
Morita H;Ogino T;Fujiki N;Tanaka K;Gotoh TM;Seo Y;Takamata A;Nakamura S;Murakami M.;M Sogami et al.
通讯作者：
M Sogami et al.

AQP and the control of fluid transport in a salivary gland