title: Nitrous oxide neurotoxicity studies in man and rat.
abstract: To assess the effects of chronic exposure to low levels of nitrous oxide on neural function of man, the authors evaluated the neurologic condition, motor and sensory nerve conduction, and computerized tests of sensation of approximately half of the dentists in Rochester, Minnesota. Results of scored tests of neural function were not significantly different for dentists who used nitrous oxide extensively in their practices and dentists who did not. To assess the effects of chronic exposure to high levels of nitrous oxide on neural function and structure of experimental animals, groups of rats were exposed to 70 per cent N2O in 30 per cent oxygen for four hours, five days a week, for six months. Rats exposed to N2O and control rats showed no difference in well-being, in caudal nerve conduction, in axonal content and transport of acetylcholinesterase and dopamine-beta-hydroxylase, or in number and size distribution and pathologic abnormality of teased myelinated fibers. Although these results indicate a lack of peripheral nerve neurotoxicity of N2O in the rat, one cannot assume a similar lack of neurotoxicity in man with heavy exposures.
mesh_terms: D000328:Adult; D000818:Animals; D003815:Dentists; D004576:Electromyography; D006801:Humans; D008475:Median Nerve / Q000187:drug effects; D008875:Middle Aged; D009412:Nerve Fibers / Q000187:drug effects; D009413:Nerve Fibers, Myelinated / Q000187:drug effects; D009422:Nervous System Diseases / Q000139:chemically induced*; D009431:Neural Conduction / Q000187:drug effects; D009460:Neurologic Examination; D009609:Nitrous Oxide / Q000009:adverse effects*; D009784:Occupational Diseases; D010543:Peroneal Nerve / Q000187:drug effects; D051381:Rats; D012684:Sensory Thresholds; D013497:Sural Nerve / Q000187:drug effects; D014110:Touch / Q000502:physiology; D014459:Ulnar Nerve / Q000187:drug effects
chemical_list: D009609:Nitrous Oxide