Influence of lecithin on mitochondrial DNA and age-related hearing loss.
نویسندگان
چکیده
OBJECTIVES Lecithin is a polyunsaturated phosphatidylcholine (PPC), which are high energy functional and structural elements of all biologic membranes. PPC play a rate-limiting role in the activation of numerous membrane-located enzymes, including superoxide dismutase and glutathione, which are important antioxidants protecting cell membranes from damage by reactive oxygen species (ROS). ROS-induced damage to mitochondrial DNA may lead to reduced mitochondrial function in the cochlea and resultant hearing loss. STUDY DESIGN AND SETTING The effects of lecithin on aging and age-associated hearing loss were studied in rats by measuring hearing sensitivities using auditory brainstem responses (ABR). In addition, mitochondrial function as a measure of aging was assessed by determining mitochondrial membrane potentials using flow cytometry and by amplifying mitochondrial DNA deletions associated with aging. Harlan-Fischer rats aged 18 to 20 months (n = 14) were divided into 2 groups. The experimental group was supplemented orally for 6 months with lecithin, a purified extract of soybean phospholipid (Nutritional Therapeutics, Allendale, NJ). RESULTS The data obtained were compared with the control group. ABRs were recorded at 2-month intervals and showed significant preservation of hearing sensitivities in the treated subjects. Flow cytometry revealed significantly higher mitochondrial membrane potentials in the treated subjects, suggesting preserved mitochondrial function. Finally, the common aging mitochondrial DNA deletion (mtDNA(4834)) were amplified from brain and cochlear tissue including stria vascularis and auditory nerve. This specific deletion was found significantly less frequent in all tissues in the treated group compared with the controls. CONCLUSION These experiments support our hypothesis and provide evidence that lecithin may preserve cochlear mitochondrial function and protect hearing loss associated with aging.
منابع مشابه
Mitochondrial gene mutation screening in hearing loss patients, Hormozgan, Iran
Introduction: Hearing loss is the most frequent sensory disorder occurs in 1/1000 newborns. About 50% of hearing loss cases are due to genetic causes. Mutation in MTRNR1(A1555G), MTTL1(A3243G) and MTTS1(A7445G) are known to be one of the important cause of nonsyndromic Sensorineural hearing loos in some populations. This study aims to demonstrate the frequency of three mitochondrial mutatio...
متن کاملبررسی وضعیت شنوایی کارگران کارگاههای پر سروصدای کارخانه آزمایش تهران
Background : Noise-induced hearing loss is among the most common cause of occupational-related hearing loss. Nowadays, noise-induced hearing loss is a disastrous event of industrial world that may influence all races, ethnics and age groups. Methods : This cross sectional study was performed on 100 workers exposed to noisy environment (greater 85db) in Azmayesh factory. Having excluded all con...
متن کاملHearing Loss Related Quality of Life in Adolescents with Hearing Loss
Objectives: Quality of life, when referring to an individual’s health, is called health-related quality of life. The purpose of this study is to assess self-perceived hearing loss related quality of life of adolescents with hearing loss and its relationship with sex, age sub-groups or school settings with domains of quality of life. Methods: A school based survey was conducted in Tehra...
متن کاملEffects of mitochondrial mutations on hearing and cochlear pathology with age
Age-related hearing loss is a multi-factorial process involving genetic and environmental factors, including exposure to noise and ototoxic agents, as well as pathological processes. Among these is the accumulation of mitochondrial DNA mutations and deletions. The creation of a transgenic mouse with a loss-of-function deletion of the nuclear gene that encodes the polymerase required to repair d...
متن کاملEffects of Age on the Auditory System and Process of Presbycusis in the Audiology Centers of Tehran
Objectives: Hearing loss is a major public health problem and has higher prevalence in elderly persons. Present study was conducted with the aim of characterizing age-related changes on audiometric thresholds and word discrimination ability of people with age range of 30 to 100 years. Methods & Materials: Hundred ninty persons (male 53.68% and female 46.32%) in seven aged decades were studie...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Otolaryngology--head and neck surgery : official journal of American Academy of Otolaryngology-Head and Neck Surgery
دوره 127 3 شماره
صفحات -
تاریخ انتشار 2002