title: Arsenic moiety in gallium arsenide is responsible for neuronal apoptosis and behavioral alterations in rats.
abstract: Gallium arsenide (GaAs), an intermetallic semiconductor finds widespread applications in high frequency microwave and millimeter wave, and ultra fast supercomputers. Extensive use of GaAs has led to increased exposure to humans working in semiconductor industry. GaAs has the ability to dissociate into its constitutive moieties at physiological pH and might be responsible for the oxidative stress. The present study was aimed at evaluating, the principle moiety (Ga or As) in GaAs to cause neurological dysfunction based on its ability to cause apoptosis, in vivo and in vitro and if this neuronal dysfunction translated to neurobehavioral changes in chronically exposed rats. Result indicated that arsenic moiety in GaAs was mainly responsible for causing oxidative stress via increased reactive oxygen species (ROS) and nitric oxide (NO) generation, both in vitro and in vivo. Increased ROS further caused apoptosis via mitochondrial driven pathway. Effects of oxidative stress were also confirmed based on alterations in antioxidant enzymes, GPx, GST and SOD in rat brain. We noted that ROS induced oxidative stress caused changes in the brain neurotransmitter levels, Acetylcholinesterase and nitric oxide synthase, leading to loss of memory and learning in rats. The study demonstrates for the first time that the slow release of arsenic moiety from GaAs is mainly responsible for oxidative stress induced apoptosis in neuronal cells causing behavioral changes.
authors.affiliation: Division of Pharmacology and Toxicology, Defence Research and Development Establishment, Jhansi Road, Gwalior-474 001, India. sjsflora@hotmail.com
authors.forename: Swaran J S
authors.initials: SJ
authors.lastname: Flora
authors.forename: Kapil
authors.initials: K
authors.lastname: Bhatt
authors.forename: Ashish
authors.initials: A
authors.lastname: Mehta
mesh_terms: D000110:Acetylcholinesterase / Q000378:metabolism; D000818:Animals; D000831:Animals, Newborn; D017209:Apoptosis / Q000187:drug effects*; D020261:Arsenic Poisoning / Q000209:etiology* / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D001152:Arsenicals; D001522:Behavior, Animal / Q000187:drug effects*; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000187:drug effects / Q000473:pathology / Q000503:physiopathology; D004305:Dose-Response Relationship, Drug; D005708:Gallium / Q000633:toxicity*; D005979:Glutathione Peroxidase / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D006624:Hippocampus / Q000187:drug effects / Q000473:pathology / Q000503:physiopathology; D007858:Learning / Q000187:drug effects; D008297:Male; D008568:Memory / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D009410:Nerve Degeneration / Q000139:chemically induced* / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D009569:Nitric Oxide / Q000378:metabolism; D019001:Nitric Oxide Synthase / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D001152:Arsenicals; D017382:Reactive Oxygen Species; C043055:gallium arsenide; D009569:Nitric Oxide; D005708:Gallium; D005979:Glutathione Peroxidase; D019001:Nitric Oxide Synthase; D013482:Superoxide Dismutase; D005982:Glutathione Transferase; D000110:Acetylcholinesterase