Open Access
CC BY-NC-ND 4.0 · Int Arch Otorhinolaryngol 2022; 26(04): e712-e717
DOI: 10.1055/s-0042-1745856
Original Research

The Induction of Hypothyroidism during Gestation Decreases Outer Hair Cell Motility in Rat Offspring

1   Department of Health Sciences, Universidade Federal de Sergipe, São Cristóvão, SE, Brazil
2   Department of Speech, Language and Hearing, Universidade Federal de Sergipe, São Cristóvão, SE, Brazil
4   Department of Physiology, Universidade Federal de Sergipe, São Cristóvão, SE, Brazil
,
2   Department of Speech, Language and Hearing, Universidade Federal de Sergipe, São Cristóvão, SE, Brazil
,
2   Department of Speech, Language and Hearing, Universidade Federal de Sergipe, São Cristóvão, SE, Brazil
,
2   Department of Speech, Language and Hearing, Universidade Federal de Sergipe, São Cristóvão, SE, Brazil
,
1   Department of Health Sciences, Universidade Federal de Sergipe, São Cristóvão, SE, Brazil
3   Department of Veterinary Medicine, Faculdade Pio Décimo , Aracaju, SE, Brazil
4   Department of Physiology, Universidade Federal de Sergipe, São Cristóvão, SE, Brazil
,
4   Department of Physiology, Universidade Federal de Sergipe, São Cristóvão, SE, Brazil
5   Department of Science Computation, Universidade Federal de Sergipe, São Cristóvão, SE, Brazil
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4   Department of Physiology, Universidade Federal de Sergipe, São Cristóvão, SE, Brazil
› Author Affiliations
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Abstract

Introduction Perinatal hypothyroidism has a negative repercussion on the development and maturation of auditory system function. However, its long-term effect on auditory function remains unsettled.

Objective To evaluate the effect of prenatal hypothyroidism on the auditory function of adult offspring in rats.

Methods Pregnant Wistar rats were given the antithyroid drug methimazole (0.02% -1-methylimidazole-2-thiol– MMI) in drinking water, ad libitum, from gestational day (GD) 9 to postnatal day 15 (PND15). Anesthetized offspring from MMI-treated dams (OMTD) and control rats were evaluated by tympanometry, distortion product otoacoustic emission (DPOAE), and auditory brainstem response (ABR) at PNDs 30, 60, 90, and 120.

Results Our data demonstrated no middle ear dysfunction, with the OMTD compliance lower than that of the control group. The DPOAE revealed the absence of outer hair cells function, and the ABR showed normal integrity of neural auditory pathways up to brainstem level in the central nervous system. Furthermore, in the OMTD group, hearing loss was characterized by a higher electrophysiological threshold.

Conclusion Our data suggest that perinatal hypothyroidism leads to irreversible damage to cochlear function in offspring.



Publication History

Received: 28 September 2021

Accepted: 01 March 2022

Article published online:
14 June 2022

© 2022. Fundação Otorrinolaringologia. This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commecial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/)

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