RESUMO
OBJECTIVE To clarify the influence factors of hearing impairment in mice caused by lack of folic acid and the mechanism.METHODS Mice were randomly divided into 2 groups,fed with no folic acid diet and normal diet for 10 weeks.Hearing was tested by ABR.Serum homocysteine,folic acid were detected.Immune imprint method was used to analyze the expression of related protein.Cochlear tissue was tested by histological method to observe morphological changes.At the same time using the TUNEL method was used to analyse the cochlear tissue cell apoptosis.RESULTS Analysis showed that serum folate levels in mice fed without folic acid diet dropped than that of the normal group,while homocysteine levels elevated.Through the brain stem auditory records and cochlear cell apoptosis of mice severe hearing loss was found in folate deficiency group.Western blot detection showed enzyme catalysis homocysteine products increased by 50％ in folate deficiency group than that of the normal diet group.CONCLUSION The high homocysteine levels,and folate deficiency can cause hearing loss in mice and are related with the inner ear homocysteine metabolic disorders.