Influence of lecithin on mitochondrial DNA and age-related hearing loss
Auteur(s) / Author(s)
SEIDMAN Michael D. ; KHAN Mumtaz J. ; WEN XUE TANG ; QUIRK Wayne S. ;
Résumé / Abstract
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[4][8][3][4]) 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.
Revue / Journal Title
Otolaryngology and head and neck surgery  (Otolaryngol. head neck
surg.)  ISSN 0194-5998   CODEN OHNSDL
Source / Source
2002, vol. 127, no3, pp. 138-144 [7 page(s) (article)]
Langue / Language
Anglais

Editeur / Publisher
Elsevier, Saint Louis, MO, ETATS-UNIS (1979) (Revue)

Localisation / Location
INIST-CNRS, Cote INIST : 20388, 35400010932995.0020

Copyright 2006 INIST-CNRS. All rights reserved

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ou sur tout support que ce soit, ne pourra être faite sans l'accord
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or by any means, without the prior written permission of INIST-CNRS.

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