唾液由唾液腺分泌，在维持口腔及全身健康中起重要作用。唾液中99％是水，水通道蛋白5(aquaporin 5，AQP5)是唾液的水分泌的关键因素，然而其作用机制未明。本项目前期研究发现在唾液腺中存在“Actin－TRPV4－AQP5”复合体形式，其中actin 主要为F－actin（微丝microfilament），我们将复合体命名为Microfilament－TRPV4－AQP5(MT4A5)。MT4A5 与AQP5 单体之间在唾液分泌过程中存在明显的相互转换。本课题拟采用生理学、药理学和分子生物学等方法，以大鼠颌下腺为对象，探讨MT4A5 的形成以及向AQP5 单体转化的分子机制。研究二者相互转换在唾液水分泌过程中的可能作用。本研究将为进一步阐明唾液水分泌的分子机制提供新认识，为唾液分泌障碍相关疾病的预防诊断以及人工干预提供新方向。

Aquaporin 5 (AQP5) plays a key role in water secretion of saliva. However, mechanism involved in water rapid transported by AQP5 remains.unclear. This study found two forms of AQP5 existing in the submandibular glands: 27kD monomer and a ～140kD aggregation with others proteins. The transformation from aggregation to the monomer of AQP5 was detected when water secreted in salivary gland. Further Mass Spectrometry and immunoblotting of co-immunoprecipitaion of AQP5 indicated aggregation included the TRPV4 and actin. On this basis, we hypothesis microfilament-TRPV4-AQP5 (MT4A5) complex, a combined formtion of AQP5, released the monomer to regulate the function of AQP5. This project will further clarify the key mechanism of secretion of saliva water and provide new insights into the prevention, diagnosis and intervention for disorder of saliva secretion.