Why is ammonia highly toxic??
Dear Student When ammonia levels in the brain cells are high, lot of ammonia combines with lot of alpha-ketoglutarate to form lot of glutamine in brain cells. This results in lack of alpha-ketoglutarate and accumulation of glutamine in the brain cells. This leads to two events- A. TCA (Tricarboxylic acid) cycle is the main energy producing pathway in the brain cells. Lack of alpha-ketoglutarate for TCA cycle results in impairment of TCA cycle resulting in energy deficiency in brain cells. B. Glutamine has osmotic property. When levels of glutamine rise in the cells due to above mentioned phenomenon, lot of water from outside the cells move into the cells due to osmosis. This results in swelling of the brain cells. Hence energy deficiency and cell swelling result in impaired functioning of brain cells in ammonia toxicity. This specially affects astrocytes in brain. Hence ammonia is very toxic. Regard