الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Aquaporins are membrane channel proteins that increase its water permeability. It was discovered by Peter Agre in 1989 who discovered the first member of this family (AQP1). They are structurally related to a major intrinsic protein of mammalian lens. In human at least 13 members were discovered from AQP0 to AQP12 that distributed through out different body systems. Aquaporins have many important functions that differ according to their distribution it may facilitate water transport either secretion or absorption, glycerol transport, cell migration, neural signal transduction, and many other unexpected cellular roles that make them to be considered as multifunctional channels. In the kideny at least 6 AQPs are expressed. They are involved in water reabsorption and regulation of urine volume according to body needs. Also they may share in regulation of acid base balance. In digestive system they are involved in water transport in digestive tract and secretions of digestive glands (e.g. salivary, bile, and pancreatic secretion). As regard other body systems they are involved in many newly discovered function including cell migration, wound healing, neural signal transduction, central osomoreception, volume transmission, and many others. By the time the importance of these AQPs has increased and their distribution in a wide varity of body system where they provid a network for water transport in those locations. It is increasingly clear that alterations in AQPs expression or function can be rate limiting for water transport and may be involved in pathophysiology of a variety of clinical conditions from diabetes insipidus to various forms of edema and, ultimately, they could be a target for therapy in diseases of altered water homeostasis.