scholarly journals Overexpression of Angiotensin-Converting Enzyme 2 in the Rostral Ventrolateral Medulla Causes Long-Term Decrease in Blood Pressure in the Spontaneously Hypertensive Rats

Hypertension ◽  
2007 ◽  
Vol 49 (4) ◽  
pp. 926-931 ◽  
Author(s):  
Masanobu Yamazato ◽  
Yoriko Yamazato ◽  
Chengwen Sun ◽  
Carlos Diez-Freire ◽  
Mohan K. Raizada
Keyword(s):  
Blood Pressure ◽  
Angiotensin Converting Enzyme ◽  
Spontaneously Hypertensive Rats ◽  
Rostral Ventrolateral Medulla ◽  
Ventrolateral Medulla ◽  
Converting Enzyme ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Angiotensin Converting Enzyme 2

scholarly journals Overexpression of angiotensin-converting enzyme 2 attenuates tonically active glutamatergic input to the rostral ventrolateral medulla in hypertensive rats

2014 ◽  
Vol 307 (2) ◽  
pp. H182-H190 ◽  
Author(s):  
Yang-Kai Wang ◽  
Du Shen ◽  
Qiang Hao ◽  
Qiang Yu ◽  
Zhao-Tang Wu ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Angiotensin Converting Enzyme ◽  
Fluorescent Protein ◽  
Rostral Ventrolateral Medulla ◽  
Ventrolateral Medulla ◽  
Converting Enzyme ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Angiotensin Converting Enzyme 2 ◽  
Green Fluorescent

The rostral ventrolateral medulla (RVLM) plays a key role in cardiovascular regulation. It has been reported that tonically active glutamatergic input to the RVLM is increased in hypertensive rats, whereas angiotensin-converting enzyme 2 (ACE2) in the brain has been suggested to be beneficial to hypertension. This study was designed to determine the effect of ACE2 gene transfer into the RVLM on tonically active glutamatergic input in spontaneously hypertensive rats (SHRs). Lentiviral particles containing enhanced green fluorescent protein (lenti-GFP) or ACE2 (lenti-ACE2) were injected bilaterally into the RVLM. Both protein expression and activity of ACE2 in the RVLM were increased in SHRs after overexpression of ACE2. A significant reduction in blood pressure and heart rate in SHRs was observed 6 wk after lenti-ACE2 injected into the RVLM. The concentration of glutamate in microdialysis fluid from the RVLM was significantly reduced by an average of 61% in SHRs with lenti-ACE2 compared with lenti-GFP. ACE2 overexpression significantly attenuated the decrease in blood pressure and renal sympathetic nerve activity evoked by bilateral injection of the glutamate receptor antagonist kynurenic acid (2.7 nmol in 100 nl) into the RVLM in SHRs. Therefore, we suggest that ACE2 overexpression in the RVLM attenuates the enhanced tonically active glutamatergic input in SHRs, which may be an important mechanism underlying the beneficial effect of central ACE2 to hypertension.

scholarly journals Overexpression of Central ACE2 (Angiotensin-Converting Enzyme 2) Attenuates the Pressor Response to Chronic Central Infusion of Ang II (Angiotensin II)

Hypertension ◽  
2020 ◽  
Vol 76 (5) ◽  
pp. 1514-1525
Author(s):  
Anyun Ma ◽  
Lie Gao ◽  
Ahmed M. Wafi ◽  
Li Yu ◽  
Tara Rudebush ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Blood Pressure ◽  
Angiotensin Converting Enzyme ◽  
Pressor Response ◽  
Rostral Ventrolateral Medulla ◽  
Ventrolateral Medulla ◽  
Ang Ii ◽  
Converting Enzyme ◽  
Angiotensin Converting Enzyme 2 ◽  
Intracerebroventricular Infusion

We investigated the mechanism by which ACE2 (angiotensin-converting enzyme 2) overexpression alters neurohumoral outflow and central oxidative stress. Nrf2 (nuclear factor [erythroid-derived 2]-like 2) is a master antioxidant transcription factor that regulates cytoprotective and antioxidant genes. We hypothesized that upregulation of central ACE2 inhibits the pressor response to Ang II (angiotensin II) by reducing reactive oxygen species through a Nrf2/antioxidant enzyme–mediated mechanism in the rostral ventrolateral medulla. Synapsin human Angiotensin Converting Enzyme 2 positive (SynhACE2 +/+ ) mice and their littermate controls synhACE2 −/− were used to evaluate the consequence of intracerebroventricular infusion of Ang II. In control mice, Ang II infusion evoked a significant increase in blood pressure and norepinephrine excretion, along with polydipsia and polyuria. The pressor effect of central Ang II was completely blocked in synhACE2 +/+ mice. Polydipsia, norepinephrine excretion, and markers of oxidative stress in response to central Ang II were also reduced in synhACE2 +/+ mice. The MasR (Mas receptor) agonist Ang 1–7 and blocker A779 had no effects on blood pressure. synhACE2 +/+ mice showed enhanced expression of Nrf2 in the rostral ventrolateral medulla which was blunted following Ang II infusion. Ang II evoked nuclear translocation of Nrf2 in cultured Neuro 2A (N2A) cells. In synhACE2 −/− mice, the central Ang II pressor response was attenuated by simultaneous intracerebroventricular infusion of the Nrf2 activator sulforaphane; blood pressure was enhanced by knockdown of Nrf2 in the rostral ventrolateral medulla in Nrf2 floxed (Nrf2 f/f ) mice. These data suggest that the hypertensive effects of intracerebroventricular Ang II are attenuated by selective overexpression of brain synhACE2 and may be mediated by Nrf2-upregulated antioxidant enzymes in the rostral ventrolateral medulla.

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