Function of the auditory and visual systems, and of peripheral nerve, in rats after long-term combined exposure to n-hexane and methylated benzene derivatives. I. Toluene.
Rats were exposed to n-hexane, toluene, or toluene together with n-hexane, each solvent 1000 p.p.m. (1000 + 1000 p.p.m. in combined exposure), 21 hr/day, 7 days/week during 28 days. Neurophysiological recordings were made 2 days, 3 months, and one year after end of exposure. A reduction in auditory sensitivity, recorded by click evoked auditory brainstem response, was observed 2 days after exposure to toluene alone, or to toluene together with n-hexane, but not after exposure to n-hexane alone. The reduction lasted one year after the exposure. Three months after combined exposure, a synergistic enhancement of loss of auditory sensitivity was observed in the mixed exposure group. One amplitude in the flash evoked potentials was lowered in the n-hexane exposed group 2 days after exposure. No such reduction was seen after simultaneous exposure to toluene. Exposure to n-hexane alone caused a marked decrease in peripheral nerve conduction velocity 2 days and 3 months after exposure, while exposure to n-hexane together with toluene had only a small effect on this velocity.
Nylén
P
P
Department of Neuromedicine, National Institute of Occupational Health, Solna, Sweden.
Hagman
M
M
Johnson
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AC
D000200:Action Potentials / Q000187:drug effects; D000280:Administration, Inhalation; D000818:Animals; D001306:Auditory Pathways / Q000187:drug effects*; D004347:Drug Interactions; D016057:Evoked Potentials, Auditory, Brain Stem / Q000187:drug effects; D005074:Evoked Potentials, Visual / Q000187:drug effects; D006586:Hexanes / Q000008:administration & dosage / Q000633:toxicity*; D008297:Male; D009132:Muscles / Q000187:drug effects; D009431:Neural Conduction / Q000187:drug effects; D010525:Peripheral Nerves / Q000187:drug effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors; D014050:Toluene / Q000008:administration & dosage / Q000633:toxicity*; D014795:Visual Pathways / Q000187:drug effects*
D006586:Hexanes; C026385:n-hexane; D014050:Toluene