title: The relation between D-galactose injection and mitochondrial DNA 4834 bp deletion mutation.
abstract: Since,D-galactose (D-gal) overload model has been used as a premature aging model, we hypothesized that it may also lead to accelerated aging in the inner ear. Furthermore, though the mitochondrial DNA (mtDNA) 4834 bp deletion mutation has been considered as the marker of aging, there is no information available in the literature concerning the mtDNA 4834 bp deletion mutation condition of the D-gal induced premature aging model. We investigate the changes in inner ear enzymatic activity, the occurring of mtDNA 4834 bp deletion in inner ear and other tissues and the relating hearing thresholds after the administration of high dosage (150 mg/kg per day) and low dosage (50 mg/kg per day) of D-gal to rats. Furthermore, the incidence of the mtDNA 4834 bp deletion in different tissues as well as in blood sample was compared. The results showed that daily subcutaneous injections of D-gal into rats for 8 weeks could lead to the biochemical defects and mtDNA 4834 bp deletion in the inner ear tissue and other tissues, which represent the typical aging animals, but the relating hearing threshold shifts (TS) were nearly identical in the three groups. This study also indicates that using of blood samples to detect mtDNA 4834 bp deletion in clinical research might lead to a 'false negative' result. A higher sensitive result could be gained using tissue biopsy to examine mtDNA 4834 bp deletion.
authors.affiliation: Department of Otorhinolaryngology, Union Hospital of Tongji Medical College, Huazhong University of Science and Technology, Jiefang Avenue 1277, Wuhan 430022, China. ent_wjkong@yahoo.com.cn
authors.forename: Wei-jia
authors.initials: WJ
authors.lastname: Kong
authors.forename: Ying
authors.initials: Y
authors.lastname: Wang
authors.forename: Qiong
authors.initials: Q
authors.lastname: Wang
authors.forename: Yu-juan
authors.initials: YJ
authors.lastname: Hu
authors.forename: Yue-chen
authors.initials: YC
authors.lastname: Han
authors.forename: Jun
authors.initials: J
authors.lastname: Liu
mesh_terms: D000375:Aging / Q000235:genetics / Q000502:physiology; D019588:Aging, Premature / Q000139:chemically induced* / Q000235:genetics*; D000818:Animals; D004272:DNA, Mitochondrial / Q000235:genetics*; D004305:Dose-Response Relationship, Drug; D007758:Ear, Inner / Q000201:enzymology / Q000503:physiopathology*; D005188:False Negative Reactions; D005690:Galactose / Q000009:adverse effects*; D005819:Genetic Markers; D007279:Injections, Subcutaneous; D023421:Models, Animal; D009154:Mutation; D051381:Rats; D017208:Rats, Wistar
chemical_list: D004272:DNA, Mitochondrial; D005819:Genetic Markers; D005690:Galactose