Document Detail


Change of extracellular ascorbic acid in the brain cortex following ice water vestibular stimulation: an on-line electrochemical detection coupled with in vivo microdialysis sampling.
MedLine Citation:
PMID:  18706231     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
BACKGROUND: Ascorbic acid (AA) represents one of the most important enzyme co-factors, antioxidants and neuromodulators and plays an important role in the cerebral system. Increasing evidence has suggested that AA could treat certain kinds of vertigo diseases such as Meniere's disease. To elucidate the neurochemical functions associated with AA in vertigo, the change of extracellular AA in the brain cortex following caloric vestibular stimulation (CVS) was evaluated. METHODS: An on-line electrochemical detection was coupled with in vivo microdialysis to continuously monitor the change of extracellular AA in the primary somatosensory (SI) area of guinea pigs following a caloric vestibular stimulation. Sixteen guinea pigs were divided into three groups, i.e., experimental group with irrigation of the ear canal with ice water (0 degrees C) (n = 8), and two control groups, one with irrigation of the ear canal with warm water (38 degrees C) (n = 4) and the other with irrigation of the auricle with ice water (n = 4). RESULTS: In the experimental group, the ice water irrigation of the left external ear canal induced a horizontal nystagmus towards the right side lasting about 45 seconds. No nystagmus was induced by warm water irrigation of the external ear canal or by ice water irrigation of the auricle. The extracellular AA concentration significantly increased following the ice water vestibular stimulation, reaching a maximum of (130 +/- 20)% (n = 8) of the basal dialysate level (2.61 +/- 0.92) micromol/L (n = 8), lasting at least for an hour. AA level did not change distinctly after the irrigation of the left external ear canal with warm water or the irrigation of the auricle with ice water. CONCLUSIONS: The concentration of extracellular AA in the brain cortex of the SI area increased following the ice water vestibular stimulation. This demonstration may be useful for the investigation of the neurochemical processes associated with AA in the process of vertigo.
Authors:
Na Zhang; Jun-xiu Liu; Fu-rong Ma; Li-sheng Yu; Yu-qing Lin; Kun Liu; Lan-qun Mao
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Chinese medical journal     Volume:  121     ISSN:  0366-6999     ISO Abbreviation:  Chin. Med. J.     Publication Date:  2008 Jun 
Date Detail:
Created Date:  2008-08-18     Completed Date:  2008-11-26     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  7513795     Medline TA:  Chin Med J (Engl)     Country:  China    
Other Details:
Languages:  eng     Pagination:  1120-5     Citation Subset:  IM    
Affiliation:
Department of Otorhinolaryngology, Peking University Third Hospital, Beijing 100083, China.
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MeSH Terms
Descriptor/Qualifier:
Animals
Ascorbic Acid / analysis*
Cerebral Cortex / metabolism*
Electrochemistry / methods
Extracellular Space / metabolism
Guinea Pigs
Ice*
Male
Microdialysis / methods
Physical Stimulation / methods
Vestibule, Labyrinth / physiopathology*
Chemical
Reg. No./Substance:
0/Ice; 50-81-7/Ascorbic Acid

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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