Aquaporins are a family of membrane proteins that selectively conduct water molecules in and out of the cell, while at the same time preventing the passage of ions and other solutes. They can be found in animal, bacteria, and plant cells. So far 13 Aquaporins have been discovered (AQP0-AQP12) some of the Aquaporins only transport water molecules, such as AQP1, AQP2, AQP4, AQP5 and AQP8. Aquaporins that transport water and other solutes are called aquaglyceroporins, these can transport glycerol, CO2, ammonia and urea across the membrane, depending on their pore size. The aquaglyceroporins consist of AQP3, AQP7 and AQP9. AQP6 has been classified to function as an intracellular chloride channel. All of these Aquaporins can be found in different
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AQP1 is found in the blood vessels, kidney proximal tubules, eye, and ear. AQP2 is expressed in the kidney collecting ducts. These two Aquaporins deal with regulating the osmolarity and the reabsorption of the nephron (distal tubule and collecting duct).
In the research done by Noda on Aquaporins in kidney pathophysiology, the question of how much process has been made on understanding the regulation and pathophysiological roles of aquaporins is discussed. Noda talks about how under the normal conditions of hydration, AQP2 is restricted to the cytoplasm of collecting duct cells. The dehydration of the body makes AQP2 relocate to the apical membrane because the body needs to retain water. Which enables water reabsorption from the urinary tubule into the cell. Water reabsorption in the collecting ducts is very important event for maintaining water balance in the body. The process of reabsorption is regulated by AQP2, which are vasopressin hormone water channel. In order to understand what this really means, …show more content…
As they were isolating the Rh molecule, another molecule that was the size of 28 kilodaltons kept on appearing. They thought it was some part of the Rh molecule, but it turned out to be a new undiscovered molecule. Most cells move by osmosis through the lipid bilayer of cell membranes. But because of the high water permeability of some epithelial cells it was suspected, that another transport mechanism existed. The research and discovery of water channels by Agre and his colleagues, won them the nobel prize in chemistry in 2003. Without the discovery of Aquaporins, we would still think that water was actively transported on carriers, just like Na+ and other ions are. But we know now that water is reabsorbed by osmosis through Aqauporins. We also know how the kidney reabsorbs water without first reabsorbing solutes. And because of that we understand the osmolarity changes as fluid flow through the
AQP1 is found in the blood vessels, kidney proximal tubules, eye, and ear. AQP2 is expressed in the kidney collecting ducts. These two Aquaporins deal with regulating the osmolarity and the reabsorption of the nephron (distal tubule and collecting duct).
In the research done by Noda on Aquaporins in kidney pathophysiology, the question of how much process has been made on understanding the regulation and pathophysiological roles of aquaporins is discussed. Noda talks about how under the normal conditions of hydration, AQP2 is restricted to the cytoplasm of collecting duct cells. The dehydration of the body makes AQP2 relocate to the apical membrane because the body needs to retain water. Which enables water reabsorption from the urinary tubule into the cell. Water reabsorption in the collecting ducts is very important event for maintaining water balance in the body. The process of reabsorption is regulated by AQP2, which are vasopressin hormone water channel. In order to understand what this really means, …show more content…
As they were isolating the Rh molecule, another molecule that was the size of 28 kilodaltons kept on appearing. They thought it was some part of the Rh molecule, but it turned out to be a new undiscovered molecule. Most cells move by osmosis through the lipid bilayer of cell membranes. But because of the high water permeability of some epithelial cells it was suspected, that another transport mechanism existed. The research and discovery of water channels by Agre and his colleagues, won them the nobel prize in chemistry in 2003. Without the discovery of Aquaporins, we would still think that water was actively transported on carriers, just like Na+ and other ions are. But we know now that water is reabsorbed by osmosis through Aqauporins. We also know how the kidney reabsorbs water without first reabsorbing solutes. And because of that we understand the osmolarity changes as fluid flow through the