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[Changes of γ-aminobutyric acid and glycine released in the medial vestibularnucleus following acute hypotension in conscious rats.] [Ariticle in Chinese]

LI Xiang-Lan, AN Ying, JIN Qing-Hua, Jin Yuan-Zhe

Department of Physiology and Pathophysiology, College of Medicine, Yanbian University, Key Laboratory of Natural ResourcesChangbai Mountain and Functional Molecules (Yanbian University), the State Educational Ministry of China, Yanji 133000, China；2Teaching Center of Functional Experimental Science, Jilin Medical College, Jilin 132013, China

Abstract

To understand whether some amino acids in the medial vestibular nucleus (MVN) of conscious rats are involved in theregulation of blood pressure, microdialysis technique and high performance liquid chromatography (HPLC) were used to measure thechanges of γ-aminobutyric acid (GABA) and glycine (Gly) in this central area. Wistar rats (250-350 g) were randomly divided into threeexperimental groups: the control group with intact labyrinths; the ipsilateral MVN of unilateral labyrinthectomy (UL); contralateralMVN of the UL. Acute hypotension was induced by intravenous infusion of sodium nitroprusside (SNP). Unilateral chemicallabyrinthectomy was performed 14 days before the start of the experiment to eliminate afferent signals from the peripheral vestibularreceptors in the inner ear. Blood pressure decreased by 30% after SNP injection. In the control group, GABA and Gly release reducedto 43.53%±6.58% (P<0.01) and 62.24%±7.51% (P<0.01) respectively in the MVN following SNP-induced acute hypotension inconscious rats. In the contralateral MVN of UL, GABA and Gly release also reduced to 45.85%±17.27% (P<0.01) and 73.30%±3.00%(P<0.01) respectively following SNP-induced acute hypotension in conscious rats. In contrast, in the ipsilateral MVN of UL, GABAand Gly releases were not changed following SNP-induced acute hypotension in conscious rats. These results suggest that the SNPinduced acute hypotension may influence the activity of the neurons in the MVN by the afferent impulses from the peripheralvestibular organ, and that GABA and Gly may be involved in this process.

Key words: hypotension; medial vestibular nucleus; γ-aminobutyric acid; glycine

Received: 2009-12-09　　Accepted: 2009-12-31

Corresponding author: 金元哲　　E-mail: y-z-jin@ybu.edu.cn

Citing This Article：

LI Xiang-Lan, AN Ying, JIN Qing-Hua, Jin Yuan-Zhe. [Changes of γ-aminobutyric acid and glycine released in the medial vestibularnucleus following acute hypotension in conscious rats.] [Ariticle in Chinese] . Acta Physiol Sin 2010; 62 (1): 30-34 (in Chinese with English abstract).