This enzyme catalyses the oxidative deamination of glutamate to ammonium and ketoglutarate; the reaction is readily reversible, and the direction of reaction towards deamination of glutamate or glutamate formation depends on the relative concentrations of the various substrates.
As the concentration of ammonium rises, so the reaction proceeds in the direction of formation of glutamate from ketoglutarate. The effect of forming glutamate from ketoglutarate is to deplete the mitochondrial pool of ketoglutarate, which is a key intermediate in the citric acid cycle. As a result, the rate of citric acid cycle activity falls, so reducing very considerably the rate of formation of ATP.
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Knepper, M. Ammonium transport in the kidney. Kosenko, E. What is ammonia? In pure form, it is known as anhydrous ammonia and is hygroscopic readily absorbs moisture. Ammonia has alkaline properties and is corrosive. Ammonia gas dissolves easily in water to form ammonium hydroxide, a caustic solution and weak base. Ammonia gas is easily compressed and forms a clear liquid under pressure. Ammonia is usually shipped as a compressed liquid in steel containers.
Ammonia is not highly flammable, but containers of ammonia may explode when exposed to high heat. How is ammonia used? How can people be exposed to ammonia? What are the immediate health effects of ammonia exposure? How is ammonia exposure treated? Will laboratory tests assist in making treatment decisions if someone has been exposed to ammonia?
How can I get more information about ammonia? Call the following numbers, or visit the websites listed among the "Sources. Updated: July 28, Revised: May Your browser does not support iFrames. The effects of ammonia on brain cells have been studied by many researchers, but they have tended to look at single cells or tissue samples. Rangroo Thrane explains:. Our research shows that swelling of glial cells is not required for ammonia to be toxic to the brain. Three-dimensional imaging and volume analyses of individual cells showed, paradoxically, that the glial cells in the cerebral cortex shrink during ammonia toxicity.
Images of intact mouse brains enabled the researchers to draw these conclusions. By using a new imaging technology called two-photon microscopy they were able to observe the microscopic effect of ammonia on nerve and glial cells in living mice. Photo: Gunnar F. Lothe, UiO. In addition to uncovering the mechanism behind ammonia toxicity, Rangroo Thrane and her colleagues also identified a possible treatment.
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