Role of angiotensin-(1-7) in amino-acid-neurotransmitter-mediated blood pressure regulation in rat rostral ventrolateral medulla

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WANG Jin()
SHEN Lin-lin()
CAO Yin-Xiang()
SUN Zhong-jie()
WANG Qiang()
ZHU Da-Nian()
Journal Title:
Volume 53, Issue 01, 2001
Key Word:

Abstract: The present study was undertaken to investigate the linkage between angiotensin-(1-7) [Ang-(1-7)] and the release of amino acid neurotransmitters in the the rostral ventrolateral medulla (RVLM) by techniques of microinjection, microdialysis combined with high performance liquid chromatography (HPLC)-fluorescent detection. Unilateral microinjection of Ang-(1-7) into the RVLM of anesthetized rats produced an increase in mean arterial pressure (MAP) accompanied by an increased release of glutamate (Glu). In contrast, microinjection of Ang779, a selective antagonist of Ang-(1-7) receptor, caused a decrease in MAP with a decreased releaceof Glu and an increased release of glycine,taurine and r-aminobutyric acid.The pressor effect of Ang-(1-7)and the depressor effect of Ang779 were in part blocked by corresponding andtagonists of aminoacid receptors.These results suggest that the pressor effect of Ang-(1-7)in the RVLM may be partially due to an increased release of Glu,whereas the depressor effect of Ang779 may be partially attributed to a decreased release of Glu and an increased release of inhibitory amino acid neurotransmitters

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