Combined effects of simultaneous exposure to toluene and ethanol on auditory function in rats.
Three experimental groups and one control group of Long-Evans rats were used to study the combined effects of toluene and ethanol on auditory function. The first experimental group was exposed to toluene vapors (1750 ppm, 6 h/day, 5 days/week, 4 weeks), the second one was daily gavaged with a saline solution of ethanol (4 g/kg, 4 weeks), and the last group was simultaneously exposed to both toluene and ethanol. Auditory function was tested by recording brain stem (inferior colliculus) auditory-evoked potentials for audiometric frequencies ranging from 2 to 32 kHz. Urinary hippuric acid was dosed to check the toluene metabolism during the experiments. Ethanol clearly modified the toluene metabolism in the present experimental conditions. As a result, the hearing loss induced by a simultaneous exposure to both ethanol and toluene was larger than that induced by exposure to toluene alone.
Campo
P
P
Institut National de Recherche et de Sécurité, Laboratoire Multinuisances, Vandoeuvre, France. campo@inrs.fr
Lataye
R
R
Cossec
B
B
Villette
V
V
Roure
M
M
Barthelemy
C
C
D000704:Analysis of Variance; D000818:Animals; D001299:Audiometry; D000431:Ethanol / Q000633:toxicity*; D016057:Evoked Potentials, Auditory, Brain Stem / Q000187:drug effects*; D006626:Hippurates / Q000652:urine; D008855:Microscopy, Electron, Scanning; D051381:Rats; D013997:Time Factors; D014050:Toluene / Q000633:toxicity*
D006626:Hippurates; D014050:Toluene; D000431:Ethanol; C030514:hippuric acid