title: MiADMSA reverses impaired mitochondrial energy metabolism and neuronal apoptotic cell death after arsenic exposure in rats.
abstract: Arsenicosis, due to contaminated drinking water, is a serious health hazard in terms of morbidity and mortality. Arsenic induced free radicals generated are known to cause cellular apoptosis through mitochondrial driven pathway. In the present study, we investigated the effect of arsenic interactions with various complexes of the electron transport chain and attempted to evaluate if there was any complex preference of arsenic that could trigger apoptosis. We also evaluated if chelation with monoisoamyl dimercaptosuccinic acid (MiADMSA) could reverse these detrimental effects. Our results indicate that arsenic exposure induced free radical generation in rat neuronal cells, which diminished mitochondrial potential and enzyme activities of all the complexes of the electron transport chain. Moreover, these complexes showed differential responses towards arsenic. These early events along with diminished ATP levels could be co-related with the later events of cytosolic migration of cytochrome c, altered bax/bcl(2) ratio, and increased caspase 3 activity. Although MiADMSA could reverse most of these arsenic-induced altered variables to various extents, DNA damage remained unaffected. Our study for the first time demonstrates the differential effect of arsenic on the complexes leading to deficits in bioenergetics leading to apoptosis in rat brain. However, more in depth studies are warranted for better understanding of arsenic interactions with the mitochondria.
authors.affiliation: Division of Pharmacology and Toxicology, Defence Research and Development Establishment, Gwalior-474 002, India.
authors.forename: Nidhi
authors.initials: N
authors.lastname: Dwivedi
authors.forename: Ashish
authors.initials: A
authors.lastname: Mehta
authors.forename: Abhishek
authors.initials: A
authors.lastname: Yadav
authors.forename: B K
authors.initials: BK
authors.lastname: Binukumar
authors.forename: Kiran Dip
authors.initials: KD
authors.lastname: Gill
authors.forename: Swaran J S
authors.initials: SJ
authors.lastname: Flora
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D020261:Arsenic Poisoning / Q000188:drug therapy*; D001921:Brain / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D002478:Cells, Cultured; D002614:Chelating Agents / Q000494:pharmacology*; D004579:Electron Transport / Q000187:drug effects; D003576:Electron Transport Complex IV / Q000187:drug effects / Q000378:metabolism; D004734:Energy Metabolism / Q000187:drug effects*; D008297:Male; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects*; D009245:NADH Dehydrogenase / Q000187:drug effects / Q000378:metabolism; D009474:Neurons / Q000187:drug effects / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000032:analysis; D004113:Succimer / Q000031:analogs & derivatives* / Q000494:pharmacology; D013385:Succinate Dehydrogenase / Q000187:drug effects / Q000378:metabolism
chemical_list: D002614:Chelating Agents; D017382:Reactive Oxygen Species; C091888:monoisoamyl-2,3-dimercaptosuccinate; D004113:Succimer; D013385:Succinate Dehydrogenase; D009245:NADH Dehydrogenase; D003576:Electron Transport Complex IV