Wei Xue-mei, Yang Yuan, Liang Chuang-yu, Zheng Zhong
Department of Otorhinolaryngology, Chengdu 363rd Hospital, Chengdu, Sichuan, 610041, P. R. China.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi. 2006 Dec;23(6):673-6.
To determine weather or not the mtDNA(4568) deletions in guinea-pig contribute to the development of presbycusis.
Forty-four guinea-pigs were divided into 2 groups: group A (young control group, normal hearing, 22 guineas) and group B (aged group). The group B was subdivided into group B(1) (old normal hearing, 6 guineas) and group B(2) (old hearing loss, 16 guineas). First the guineas were tested by auditory brainstem response (ABR), and then the Cortis's tissues, auditory nerve tissues, brain and blood were harvested and the total DNA was extracted. The mtDNA(4568) deletion was analyzed by PCR.
Hearing loss was occurred with age. The mtDNA(4568) deletion incidence of aged group in all tissues was significant higher than that of young control group (P< 0.05). The incidence of mtDNA deletion in Cortis's and auditory nerve with presbycusis (B(2) group) were significant higher than that of aged normal hearing group (B(1) group) (P< 0.05). The incidence of mtDNA deletion in brain and blood was not significantly different between presbycusis and aged normal hearing group (P> 0.05).
mtDNA(4568) deletion of guinea-pig possibly contributes to aging and mtDNA(4568) deletion in Cortis's and auditory nerve tissues of guinea-pig may be associated with presbycusis. There is no enough evidence to prove that the mtDNA(4568) deletions in brain and blood are related with presbycusis.
确定豚鼠线粒体DNA（4568）缺失是否与老年性聋的发生有关。
44只豚鼠分为2组：A组（青年对照组，听力正常，22只）和B组（老年组）。B组再分为B（1）组（老年听力正常，6只）和B（2）组（老年听力减退，16只）。首先用听性脑干反应（ABR）对豚鼠进行检测，然后采集耳蜗组织、听神经组织、脑和血液，提取总DNA。用聚合酶链反应（PCR）分析线粒体DNA（4568）缺失情况。
听力损失随年龄增加而出现。老年组所有组织中线粒体DNA（4568）缺失发生率显著高于青年对照组（P<0.05）。老年性聋组（B（2）组）耳蜗和听神经中线粒体DNA缺失发生率显著高于老年听力正常组（B（1）组）（P<0.05）。老年性聋组与老年听力正常组脑和血液中线粒体DNA缺失发生率差异无统计学意义（P>0.05）。
豚鼠线粒体DNA（4568）缺失可能与衰老有关，豚鼠耳蜗和听神经组织中线粒体DNA（4568）缺失可能与老年性聋有关。没有足够证据证明脑和血液中线粒体DNA（4568）缺失与老年性聋有关。
