Effects of aluminum on activity of Krebs cycle enzymes and glutamate dehydrogenase in rat brain homogenate

Aluminum is a neurotoxic agent for animals and humans that has been implica ted as an etiological factor in several neurodegenerative diseases and as a destabilizer of cell membranes. Due to its high reactivity, Al3+ is able t o interfere with several biological functions, including enzymatic activiti es in key metabolic pathways. In this paper we report that, among the enzym es that constitute the Krebs cycle, only two are activated by aluminum: alp ha-ketoglutarate dehydrogenase and succinate dehydrogenase. In contrast, ac onitase, shows decreased activity in the presence of the metal ion. Al3+ al so inhibits glutamate dehydrogenase, an allosteric enzyme that is closely l inked to the Krebs cycle. A possible correlation between aluminum, the Kreb s cycle and aging processes is discussed.