The maturation state of the auditory nerve and brainstem in rats exposed to lead acetate and supplemented with ferrous sulfate

Revista Brasileira de Otorrinolaringologia

Morata, Thais C.¹  Duarte, Josilene L.²  Zucki, Fernanda³ 

[1] National Institute for Occupational Safety and Health, Atlanta, USA;Universidade Estadual PaulistaJúlio de Mesquita Filho , Bauru, Brazil;Universidade de São Paulo, Bauru, Brazil

关键词: Hearing;    Auditory evoked potentials;    Lead acetate;    Blood lead levels;    Ferrous sulfate.;   

DOI  :  10.1016/j.bjorl.2016.12.004

学科分类：医学（综合）

来源: Associacao Brasileira de Otorrinolaringologia e Cirurgia Cervicofacial

【 摘 要 】

Introduction The literature has reported the association between lead and auditory effects, based on clinical and experimental studies. However, there is no consensus regarding the effects of lead in the auditory system, or its correlation with the concentration of the metal in the blood.Objective To investigate the maturation state of the auditory system, specifically the auditory nerve and brainstem, in rats exposed to lead acetate and supplemented with ferrous sulfate.Methods 30 weanling male rats (Rattus norvegicus, Wistar) were distributed into six groups of five animals each and exposed to one of two concentrations of lead acetate (100 or 400 mg/L) and supplemented with ferrous sulfate (20 mg/kg). The maturation state of the auditory nerve and brainstem was analyzed using Brainstem Auditory Evoked Potential before and after lead exposure. The concentration of lead in blood and brainstem was analyzed using Inductively Coupled Plasma-Mass Spectrometry.Results We verified that the concentration of Pb in blood and in brainstem presented a high correlation (r = 0.951; p < 0.0001). Both concentrations of lead acetate affected the maturation state of the auditory system, being the maturation slower in the regions corresponding to portion of the auditory nerve (wave I) and cochlear nuclei (wave II). The ferrous sulfate supplementation reduced significantly the concentration of lead in blood and brainstem for the group exposed to the lowest concentration of lead (100 mg/L), but not for the group exposed to the higher concentration (400 mg/L).Conclusion This study indicate that the lead acetate can have deleterious effects on the maturation of the auditory nerve and brainstem (cochlear nucleus region), as detected by the Brainstem Auditory Evoked Potentials, and the ferrous sulphate can partially amend this effect.

【 授权许可】

CC BY