Mechanism Arsenite inhibits not only the formation of acetyl-CoA but also the enzyme succinic dehydrogenase. Arsenate can replace phosphate in many reactions. It is able to form Glc-6-arsenate in vitro; therefore it has been argued that hexokinase could be inhibited. (Eventually this may be a mechanism leading to muscle weakness in chronic arsenic poisoning.) In the glyceraldehyde 3-phosphate dehydrogenase reaction arsenate attacks the enzyme-bound thioester. The formed 1-arseno-3-phosphoglycerate is unstable and hydrolyzes spontaneously. Thus, ATP formation in glycolysis is inhibited while bypassing the phosphoglycerate kinase reaction. (Moreover, the formation of 2,3-bisphosphoglycerate in erythrocytes might be affected, followed by a higher oxygen affinity of hemoglobin and subsequently enhanced cyanosis.) As shown by Gresser (1981), submitochondrial particles synthesize adenosine-5'-diphosphate-arsenate from ADP and arsenate in presence of succinate. Thus, by a variety of mechanisms arsenate leads to an impairment of cell respiration and subsequently diminished ATP formation. This is consistent with observed ATP depletion of exposed cells and histopathological findings of mitochondrial and cell swelling, glycogen depletion in liver cells and fatty change in liver, heart and kidney.
mechanism arsenite inhibits not only the formation of acetyl-coa but also the enzyme succinic dehydrogenase arsenate can replace phosphate in many reactions it is able to form glc-6-arsenate in vitro; therefore it has been argued that hexokinase could be inhibited (eventually this may be a mechanism leading to muscle weakness in chronic arsenic poisoning) in the glyceraldehyde 3-phosphate dehydrogenase reaction arsenate attacks the enzyme-bound thioester the formed 1-arseno-3-phosphoglycerate is unstable and hydrolyzes spontaneously thus atp formation in glycolysis is inhibited while bypassing the phosphoglycerate kinase reaction (moreover the formation of 23-bisphosphoglycerate in erythrocytes might be affected followed by a higher oxygen affinity of hemoglobin and subsequently enhanced cyanosis) as shown by gresser (1981) submitochondrial particles synthesize adenosine-5'-diphosphate-arsenate from adp and arsenate in presence of succinate thus by a variety of mechanisms arsenate leads to an impairment of cell respiration and subsequently diminished atp formation this is consistent with observed atp depletion of exposed cells and histopathological findings of mitochondrial and cell swelling glycogen depletion in liver cells and fatty change in liver heart and kidney