| Autor: |
Crofton KM; Neurotoxicology Division, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711., Dean KF, Ménache MG, Janssen R |
| Jazyk: |
angličtina |
| Zdroj: |
Toxicology and applied pharmacology [Toxicol Appl Pharmacol] 1990 Aug; Vol. 105 (1), pp. 123-32. |
| DOI: |
10.1016/0041-008x(90)90364-z |
| Abstrakt: |
Trimethyltin (TMT) is a neurotoxicant known to alter auditory function. The present study was designed to compare TMT-induced auditory dysfunction using behavioral, electrophysiological, and anatomical techniques. Adult male Long-Evans hooded rats (n = 9-12/group) were acutely exposed to saline, 3, 5, or 7 mg/kg TMT. Auditory thresholds were determined 11 weeks postdosing for 5- and 40-kHz tones using reflex modification of the auditory startle response (ASR). Brainstem auditory evoked response (BAER) thresholds were determined for 5-, 40-, and 80-kHz tonal stimuli 9 weeks postdosing. Cochlear histology was assessed at 13 weeks postdosing. Functional endpoints demonstrated a high-frequency hearing loss. ASR thresholds for 40-kHz tones were elevated 25-35 dB in all dosage groups. BAER thresholds for 40- and 80-kHz tones were elevated 30-50 dB in the 5 and 7 mg/kg groups. Organ of Corti surface preparations revealed a pattern of damage suggesting classical ototoxicity. That is, outer hair cells died preferentially in regions associated with high-frequency hearing, in a dosage-dependent manner from base to apex. These data demonstrate the utility of the ASR and BAER in detecting functional alterations in audition and indicate that TMT-induced high-frequency hearing loss is associated with cochlear damage. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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