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| * Family of membrane channel proteins | | * Family of membrane channel proteins |
| * Over a dozen homologous water transporting proteins make up this family in mammals | | * Over a dozen homologous water transporting proteins make up this family in mammals |
− | * Allow rapid transport of water accross membranes | + | * Allow rapid transport of substances accross membranes |
| * Found in all life forms | | * Found in all life forms |
| * Commonly abbreviated to '''AQP''' | | * Commonly abbreviated to '''AQP''' |
| * Ones found in the kidneys are: | | * Ones found in the kidneys are: |
− | ** AQP1 - Tubules | + | ** <Font Color="#669933">'''AQP1'''</Font> - Tubules |
− | ** AQP2 - [[Collecting Duct - Anatomy & Physiology| Collecting duct]] | + | ** <Font Color="#669933">'''AQP2'''</Font> - [[Collecting Duct - Anatomy & Physiology| Collecting duct]] |
− | ** AQP3 - [[Collecting Duct - Anatomy & Physiology| Collecting duct]] | + | ** <Font Color="#CC6633">'''AQP3'''</Font> - [[Collecting Duct - Anatomy & Physiology| Collecting duct]] |
− | ** AQP4 - [[Collecting Duct - Anatomy & Physiology| Collecting duct]] | + | ** <Font Color="#669933">'''AQP4'''</Font> - [[Collecting Duct - Anatomy & Physiology| Collecting duct]] |
− | ** AQP6 - [[Collecting Duct - Anatomy & Physiology| Collecting duct (intercalated cells)]] | + | ** <Font Color="#660000">'''AQP6'''</Font> - [[Collecting Duct - Anatomy & Physiology| Collecting duct (intercalated cells)]] |
− | ** AQP 7 - [[Proximal Tubule - Anatomy & Physiology| Proximal tubule]] | + | ** <Font Color="#CC6633">'''AQP7'''</Font> - [[Proximal Tubule - Anatomy & Physiology| Proximal tubule]] |
− | ** AQP11 - Kidney | + | ** <Font Color="#9900ff">'''AQP11'''</Font> - Kidney |
| * They are colour coded according to their function | | * They are colour coded according to their function |
− | ** <Font Color="#669933">Water channels</Font> | + | ** <Font Color="#669933">'''Water channels'''</Font> |
− | ** <Font Color="#CC6633">Glycerol channels</Font> | + | ** <Font Color="#CC6633">'''Glycerol channels'''</Font> |
− | ** <Font Color="#660000">Intracellular chloride channels</Font> | + | ** <Font Color="#660000">'''Intracellular chloride channels'''</Font> |
− | ** <Font Color="#9900ff">Function Unknown</Font> | + | ** <Font Color="#9900ff">'''Function Unknown'''</Font> |
| + | |
| + | ==Function== |
| + | |
| + | * They allow the reabsorption of water, glycerol and chlorine from the filtrate |
| + | * Without the water ones producing concentrated urine would be impossible |
| + | |
| + | |
| + | * AQP2 is stored in vesicle membranes within the [[Collecting Duct - Anatomy & Physiology #Principal Cells| principal cells]] of the [[Collecting Duct - Anatomy & Physiology| collecting ducts]] |
| + | * [[Useful definitions - Renal Anatomy & Physiology| ADH]] causes these vesicles to attach to the principal cell membranes. |
| + | * This is how ADH works. |
| + | ** The higher its concentration the more AQP2 avaiable to water within the collecting duct |
| + | ** The more water is reabsorbed |
| + | ** Thanks to the gradient created by the hypertonic medulla which is present due to the countercurrent multiplier in the [[Loop Of Henle - Anatomy & Physiology| Loop of Henle]] |
| + | * This system allows both concentrated and dilute urine to be produced depending on ADH secretion and therefore the density of aquaporins in the principal cell membranes |
| | | |
| ==Why Do We Need Aquaporins== | | ==Why Do We Need Aquaporins== |
| * Contrary to popular belief diffusion of water accross lipid bilayers is too slow for most physiological processes | | * Contrary to popular belief diffusion of water accross lipid bilayers is too slow for most physiological processes |
| * Aquaporins solve this problem | | * Aquaporins solve this problem |