title: Functional and morphological effects of repeated sodium arsenite exposure on rat peripheral sensory nerves.
abstract: Exposure to inorganic arsenic (iAs) is known to result in peripheral neuropathy. To better understand the functional and morphological consequences of iAs exposure, we examined the electrophysiological and histological characteristics of the sensory sural nerves in adult Male Wistar rats following 30 days of sodium arsenite administration by gavage (10 mg/kg body weight/day). Arsenic (As) levels in the peripheral nerves of exposed animals were about 150 times greater than those in controls. Lipid peroxidation was also increased in iAs-exposed animals. Compound action potentials (CAPs) evoked in iAs-exposed nerves were characterized by a slower conduction velocity ( approximately 26%). iAs-exposed nerves also showed a trend towards a decreased CAP area ( approximately 35%). These electrophysiological changes were consistent with histological alterations such as a approximately 56% decrease in myelin thickness. In addition, the perimeter and transverse area of axons were reduced to 29% and 45% of control, respectively. Our results suggest that accumulation of As produced by iAs exposure induces oxidative damage, severe demyelination, and other morphological alterations in axons of peripheral nerves. These changes may, in turn, induce changes in the generation and propagation of action potentials in peripheral nerves, leading to decreased transmission of information from peripheral sensory organs to the central nervous system.
authors: Cinvestav, Sección Externa de Toxicología, Av. Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, México D. F., 07360, México.
authors: Erika
authors: E
authors: García-Chávez
authors: Bertha
authors: B
authors: Segura
authors: Horacio
authors: H
authors: Merchant
authors: Ismael
authors: I
authors: Jiménez
authors: Luz M
authors: LM
authors: Del Razo
mesh_terms: D000200:Action Potentials / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D000818:Animals; D018053:Arsenites / Q000633:toxicity*; D004558:Electric Stimulation / Q000379:methods; D004791:Enzyme Inhibitors / Q000633:toxicity*; D015227:Lipid Peroxidation / Q000187:drug effects; D008297:Male; D009431:Neural Conduction / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D051381:Rats; D017208:Rats, Wistar; D017670:Sodium Compounds / Q000633:toxicity*; D013497:Sural Nerve / Q000033:anatomy & histology / Q000187:drug effects / Q000502:physiology
chemical_list: D018053:Arsenites; D004791:Enzyme Inhibitors; D017670:Sodium Compounds; C017947:sodium arsenite