[The difference of mitochondrial DNA 4,834 bp deletion mutation in tissues of inner ear and kidney and skeletal muscle of rat].
OBJECTIVE
To explore the difference of mitochondrial DNA 4,834 bp deletion mutation in tissues of inner ear, kidney and skeletal muscle and to discuss the possible mechanism of this kind of mutation in doxorubicin induced mtDNA 4,834 bp deletion mutation rat model.


METHODS
Twenty-eight Wistar rats were randomly divided into two groups, one was experimental group (18 rats), the other was the blank control group (10 rats). The rats of experimental group were treated with intraperitoneal injection doxorubicin (1 mg/kg) twice a week for 3 months. The blank controls received an equivalent volume of saline instead. The tissues of inner ear, kidney and skeletal muscle were harvested and the mitochondrial DNA 4,834 bp deletion mutation was detected by nested-PCR (nested polymers chain reaction) technique. The product of PCR was sequenced directly.


RESULTS
Two rats of the experimental group and the blank group died during the experiment. The frequency of the mitochondrial DNA 4,834 bp deletion mutation of inner ear, kidney and skeletal muscle were 68.75% (11/16), 75.00% (12/16) and 100.00% (16/16) respectively. The difference of this kind of mutation between tissues of the inner ear and the skeletal muscle was statistic significance (P < 0.05). There were no significant difference between the inner ear tissue and the kidney tissue (P > 0.05). None of the rats of the blank control group carry this kind of mitochondrial DNA mutation.


CONCLUSIONS
The mitochondrial DNA 4,834 bp deletion mutation could be induce by doxorubicin in rats, and a notable difference were found of the frequencies of this kind of mutation between tissues of the inner ear and the skeletal muscle. So it suggested that this kind of mitochondrial DNA common deletion mutation was tissue specific.
Han
Yuechen
Y
Department of Otorhinolaryngology, the Union Hospital, Tongji Medical College, Huazhong University of Science and Techonlogy, Wuhan, 430022, China.
Kong
Weijia
W
Wang
Haibo
H
Fan
Zhaomin
Z
D000818:Animals; D004272:DNA, Mitochondrial / Q000235:genetics*; D004317:Doxorubicin / Q000633:toxicity; D007758:Ear, Inner; D017353:Gene Deletion; D007668:Kidney / Q000378:metabolism; D018482:Muscle, Skeletal / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D017384:Sequence Deletion / Q000187:drug effects
D004272:DNA, Mitochondrial; D004317:Doxorubicin