Combined effects of aspirin and noise in causing permanent hearing loss.
Several authors have investigated the interaction of noise and aspirin in hearing loss, with conflicting results. We studied the combined effects of noise and high doses of aspirin on hearing in rats. Thirty-eight Sprague-Dawley rats were divided into the following five groups: (1) controls; (2) aspirin only; (3) noise only; (4) 8-day per 200 mg of aspirin per noise; and (5) 12-day per 200 mg of aspirin per noise. Auditory brain-stem-evoked responses were measured in each animal prior to, 24 hours after, and 3 weeks after aspirin and noise exposure. The animals were killed and hair cells were counted in 200-micron segments and expressed graphically. Results showed significant differences in permanent threshold shift and hair cell loss between all noise-exposed animals and non-noise-exposed animals. There was also a significantly greater amount of hair cell loss in group 5 when compared with groups 3 or 4. The 12-day per 200 mg of aspirin per noise regimen (group 5) also proved to be fatal for 6 of 15 of these animals, and caused significant weight loss in the survivors. No weight loss or deaths were noted in any other group.
Carson
S S
SS
Division of Otolaryngology-Head and Neck Surgery, University of North Carolina School of Medicine, Chapel Hill 27599-7070.
Prazma
J
J
Pulver
S H
SH
Anderson
T
T
D000818:Animals; D001241:Aspirin / Q000009:adverse effects*; D004357:Drug Synergism; D005072:Evoked Potentials, Auditory; D005260:Female; D006198:Hair Cells, Auditory / Q000473:pathology; D034381:Hearing Loss / Q000139:chemically induced / Q000209:etiology*; D008297:Male; D009622:Noise / Q000009:adverse effects*; D051381:Rats; D011919:Rats, Inbred Strains
D001241:Aspirin