title: Radix astragali inhibits the down-regulation of connexin 26 in the stria vascularis of the guinea pig cochlea after acoustic trauma.
abstract: Connexin 26 (cx26) plays an important role in the intercellular signaling and is related to K(+) metabolism in stria vascularis (SV). Reactive oxygen species (ROS) are negative regulators of cx26, reducing intercellular coupling in cochlea. ROS plays an important role in acoustic trauma. Radix astragali is a natural antioxidant that decreases impulse noise-induced hearing loss through its ability to inhibit ROS. The purpose of this study was to investigate if radix astragali has the potential to reduce the change of cx26 in SV from impulse noise. Guinea pigs in the experimental group were administered radix astragali intraperitoneally. Auditory thresholds were assessed by sound-evoked auditory brainstem response (ABR) at click and tone bursts of 8, 16 and 32 kHz, 24 h before and 72 h after exposure to impulse noise. 4-Hydroxynonenal, cx26 and KCNQ1 were determined immunohistochemically in SV. SV was analyzed by transmission electron microscopy. Radix astragali significantly reduced the ABR deficits and the SV damage, and decreased the shifts of the expression of cx26 and KCNQ1 in the SV. These results suggest that the beneficial effect of radix astragali on impulse noise-induced hearing loss may be also due to its ability to reduce the change of cx26 in SV.
authors.affiliation: Department of Otolaryngology, Guangzhou General Hospital of Guangzhou Military Command, Liu Hua Road 111, Guangzhou, 510010, China, dr_xiong@163.com.
authors.forename: Min
authors.initials: M
authors.lastname: Xiong
authors.forename: Yazhen
authors.initials: Y
authors.lastname: Zhu
authors.forename: Huangwen
authors.initials: H
authors.lastname: Lai
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Fu
authors.forename: Wenting
authors.initials: W
authors.lastname: Deng
authors.forename: Chuanhong
authors.initials: C
authors.lastname: Yang
authors.forename: Qinglian
authors.initials: Q
authors.lastname: He
authors.forename: Guangjuan
authors.initials: G
authors.lastname: Zheng
mesh_terms: D000447:Aldehydes / Q000378:metabolism; D000818:Animals; D027885:Astragalus propinquus; D001309:Auditory Threshold; D000072259:Connexin 26; D017630:Connexins / Q000378:metabolism*; D004195:Disease Models, Animal; D015536:Down-Regulation; D004365:Drugs, Chinese Herbal / Q000627:therapeutic use*; D016057:Evoked Potentials, Auditory, Brain Stem / Q000502:physiology; D006168:Guinea Pigs; D006317:Hearing Loss, Noise-Induced / Q000188:drug therapy* / Q000209:etiology / Q000378:metabolism*; D013316:Stria Vascularis / Q000378:metabolism*
chemical_list: D000447:Aldehydes; D017630:Connexins; D004365:Drugs, Chinese Herbal; D000072259:Connexin 26; C027492:Huang Qi; C027576:4-hydroxy-2-nonenal