[Changes of glutamate and taurine released in the medial vestibular nucleus following acute hypotension].
In order to understand whether some special amino acids in the medial vestibular nucleus (MVN) of rats are involved in the regulation of blood pressure, we used microdialysis technique and high performance liquid chromatography (HPLC) to measure the changes of glutamate and taurine in this central area. Acute hypotension was induced by hemorrhage from the femoral artery. It was observed that the basal release of glutamate and taurine in the MVN was stable about 90 min after the beginning of microdialysis. The basal release of glutamate was (18.96 +/- 0.27) pmol/sample (8 mul), and that of taurine was (7.73 +/- 0.05) pmol/sample (8 mul). Glutamate release increased (P<0.05) and taurine release reduced (P<0.05) in the MVN in the hemorrhage-induced acute hypotensive rats. Nevertheless, these changes were not observed in the hemorrhage-induced acute hypotensive rats which were pretreated by infusing 2% lidocaine into the middle ear or 100 mg arsanilic acid into the tympanic cavity. These results suggest that the hemorrhage-induced acute hypotention can influence the activity of the neurons in the MVN by the afferent impulses from vestibular organ, and that some special amino acid transmitters in the MVN are involved in this process.
Yu
Hai-Ling
HL
Department of Pharmacology, College of Medicine, Yanbian University, Yanji 133000, China.
An
Ying
Y
Bing
Yan-Hua
YH
Jin
Qing-Hua
QH
Cui
Xun
X
Jin
Yuan-Zhe
YZ
D000818:Animals; D001794:Blood Pressure / Q000502:physiology; D018698:Glutamic Acid / Q000378:metabolism*; D007022:Hypotension / Q000378:metabolism / Q000503:physiopathology*; D008297:Male; D017551:Microdialysis / Q000379:methods; D051381:Rats; D017208:Rats, Wistar; D013654:Taurine / Q000378:metabolism*; D014726:Vestibular Nuclei / Q000378:metabolism* / Q000503:physiopathology
D013654:Taurine; D018698:Glutamic Acid