Angiotensin II Suppresses Rev-erbα Expression in THP-1 Macrophages via the Ang II Type 1 Receptor/Liver X Receptor α Pathway

Background/Aims: Angiotensin II (Ang II) regulates the expression of some core clock genes; excess Ang II leads to atherosclerosis advancement. Macrophage Rev-erbα mediates clockwork and inflammation, and plays a role in atherosclerotic lesion progression. However, the role of Ang II in regulating Rev-erbα expression in macrophages remains unclarified. Methods: We induced THP-1 macrophages by phorbol 12-myristate 13-acetate and investigated the effect of Ang II on Rev-erbα expression via real-time polymerase chain reaction, western blotting and small interfering RNA (siRNA) techniques. The cytotoxicity of the Rev-erbα agonist SR9009 was analyzed using a (3-[4,5-dimethylthiazol-2-yl])-2,5- diphenyltetrazolium bromide assay. Results: Ang II suppressed Rev-erbα mRNA and protein expression in THP-1 macrophages in a dose and time dependent manner. This effect was mediated via Ang II type 1 receptor (AT1R), and not Ang II type 2 receptor or peroxisome proliferator-activated receptor γ (PPARγ). Consistent with Rev-erbα expression regulated by Ang II, the liver X receptor α (LXRα) protein expression was downregulated in a time-dependent manner after Ang II treatment. The activation or silence of LXRα significantly increased or decreased Rev-erbα expression regulated by Ang II, respectively. This suggests that LXRα is involved in the effect of Ang II on Rev-erbα expression. MMP-9 mRNA expressions were significantly suppressed by SR9009 in THP-1 and RAW264.7 macrophages; moreover, SR9009-treatment significantly reduced Ang II–induced MMP-9 protein expressions in two types of macrophages. Conclusion: Ang II downregulates Rev-erbα expression in THP-1 macrophages via the AT1R/LXRα pathway.

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Angiotensin II type 1 receptor blocker attenuates the activation of ERK and NADPH oxidase by mechanical strain in mesangial cells in the absence of angiotensin II

AJP Renal Physiology ◽

10.1152/ajprenal.00580.2007 ◽

2009 ◽

Vol 296 (5) ◽

pp. F1052-F1060 ◽

Cited By ~ 24

Author(s):

Junichi Yatabe ◽

Hironobu Sanada ◽

Midori Sasaki Yatabe ◽

Shigeatsu Hashimoto ◽

Minoru Yoneda ◽

...

Keyword(s):

Oxidative Stress ◽

Angiotensin Ii ◽

Nadph Oxidase ◽

Mesangial Cells ◽

Mechanical Strain ◽

Dependent Manner ◽

Ang Ii ◽

Erk Phosphorylation ◽

Extracellular Signal

It has been reported that mechanical strain activates extracellular signal-regulated protein kinases (ERK) without the involvement of angiotensin II (Ang II) in cardiomyocytes. We examined the effects of mechanical strain on ERK phosphorylation levels in the absence of Ang II using rat mesangial cells. The ratio of phosphorylated ERK (p-ERK) to total ERK expression was increased by cyclic mechanical strain in a time- and elongation strength-dependent manner. With olmesartan [Ang II type 1 receptor (AT1R) antagonist] pretreatment, p-ERK plateau levels decreased in a dose-dependent manner (EC50 = 1.3 × 10−8 M, maximal inhibition 50.6 ± 11.0% at 10−5 M); a similar effect was observed with RNA interference against Ang II type 1A receptor (AT1AR) and Tempol, a superoxide dismutase mimetic. In addition to the inhibition of p-ERK levels, olmesartan blocked the increase in cell surface and phosphorylated p47phox induced by mechanical strain and also lowered the mRNA expression levels of NADPH oxidase subunits. These results demonstrate that mechanical strain stimulates AT1R to phosphorylate ERK in mesangial cells in the absence of Ang II. This mechanotransduction mechanism is involved in the oxidative stress caused by NADPH oxidase and is blocked by olmesartan. The inverse agonistic activity of this AT1R blocker may be useful for the prevention of mesangial proliferation and renal damage caused by mechanical strain/oxidative stress regardless of circulating or tissue Ang II levels.

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mTORC1 Signaling Contributes to Drinking But Not Blood Pressure Responses to Brain Angiotensin II

Endocrinology ◽

10.1210/en.2016-1243 ◽

2016 ◽

Vol 157 (8) ◽

pp. 3140-3148 ◽

Cited By ~ 4

Author(s):

Kenjiro Muta ◽

Donald A. Morgan ◽

Justin L. Grobe ◽

Curt D. Sigmund ◽

Kamal Rahmouni

Keyword(s):

Angiotensin Ii ◽

Water Intake ◽

Drinking Behavior ◽

Subfornical Organ ◽

Dependent Manner ◽

Ang Ii ◽

Mtorc1 Signaling ◽

Wide Range ◽

The Brain

Mechanistic target of rapamycin complex 1 (mTORC1) is a molecular node that couples extracellular cues to a wide range of cellular events controlling various physiological processes. Here, we identified mTORC1 signaling as a critical mediator of angiotensin II (Ang II) action in the brain. In neuronal GT1–7 cells, we show that Ang II stimulates neuronal mTORC1 signaling in an Ang II type 1 receptor-dependent manner. In mice, a single intracerebroventricular (ICV) injection or chronic sc infusion of Ang II activated mTORC1 signaling in the subfornical organ, a critical brain region in cardiovascular control and fluid balance. Moreover, transgenic sRA mice with brain-specific overproduction of Ang II displayed increased mTORC1 signaling in the subfornical organ. To test the functional role of brain mTORC1 in mediating the action of Ang II, we examined the consequence of mTORC1 inhibition with rapamycin on Ang II-induced increase in water intake and arterial pressure. ICV pretreatment with rapamycin blocked ICV Ang II-mediated increases in the frequency, duration, and amount of water intake but did not interfere with the pressor response evoked by Ang II. In addition, ICV delivery of rapamycin significantly reduced polydipsia, but not hypertension, of sRA mice. These results demonstrate that mTORC1 is a novel downstream pathway of Ang II type 1 receptor signaling in the brain and selectively mediates the effect of Ang II on drinking behavior.

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Abstract 1311: Bone Marrow Angiotensin II Type 1 Receptor Augments Atherosclerosis by Promoting Monocyte/Macrophage Lineage Differentiation from Hematopoietic Stem Cells

Circulation ◽

10.1161/circ.116.suppl_16.ii_268-a ◽

2007 ◽

Vol 116 (suppl_16) ◽

Author(s):

Yoshinori Tsubakimoto ◽

Hiroyuki Yamada ◽

Hirokazu Yokoi ◽

Hiroki Takata ◽

Hiroyuki Kawahito ◽

...

Keyword(s):

Stem Cells ◽

Bone Marrow ◽

Angiotensin Ii ◽

Hematopoietic Stem Cells ◽

Atherosclerotic Lesion ◽

Ang Ii ◽

Hematopoietic Stem ◽

Apoe Ko Mice ◽

Apoe Ko

[BACKGROUND] The angiotensin II (Ang II) type 1 (AT 1 ) receptor is crucially involved in atherogenesis, but bone marrow (BM) AT 1 -mediated proatherogenic action remains undefined- . [METHOD AND RESULT] BM-derived mononuclear cells (BM-MNCs) more abundantly express AT 1 than VSMCs (2.2 fold) with similar affinities to Ang II. BM cells in 8-week-old apoE-deficient −/− ) or wild-type (Agtr1 + / + ) cells. Four (apoE-KO) mice were replaced with AT 1 -deficient (Agtr1 weeks after the initiation of western diet and Ang II infusion (500ng/kg/min), atherosclerotic lesion area in aortic root was examined. ApoE-KO mice reconstituted with Agtr1 −/− marrow (apoE-KO/BM-Agtr1 −/− ) showed a significant reduction in atherosclerotic lesions compared with apoE-KO/BM-Agtr1 + / + mice (55%, P <0.05). The accumulation of macrophages was attenuated in apoE-KO/BM-Agtr1 −/− mice (55%, P <0.05), concomitant with a decrease in the number of circulating Ly-6C hi monocytes (76%, P <0.01). The numbers of circulating CCR2 + and CX3CR1 + monocytes were also reduced in apoE-KO/BM-Agtr1 −/− mice (87±16 vs 298±66; CCR2 + monocyte, 72±12 vs 550±119 cells/μl; CX3CR1 + monocyte, respectively, P <0.01). Furthermore, the number of macrophage progenitor cells defined by M-CSF stimulated macrophage colony-forming unit was markedly reduced by 82 % (p<0.01) in Agtr1 −/− compared with Agtr1 + / + mice. We next examined the effect of BM-AT 1 on the number of hematopoietic stem cells (HSCs), common myeloid progenitors (CMP), and granulocyte/macrophage progenitors (GMP) to determine at which point of the lineage pathway, BM-AT 1 is involved. The number of HSCs did not differ between the two groups (3.6±0.8 vs 2.9±0.6 × 10 3 cells/tibia, P =n.s.), whereas the numbers of CMP and GMP were much lower in apoE-KO/BM-Agtr1 −/− mice (4.7±0.7 vs 10.2±1.4 ×10 3 cells/tibia, 9.9±2.7 vs 20.2±2.8 × 10 3 cells/tibia, respectively, P <0.05). [CONCLUSION] BM-MNCs expressed the abundant densities of AT1, and AT1-mediated signals on BM-MNCs exaggerated atherosclerotic lesion development. BM-AT 1 is closely implicated in the differentiation of HSCs into macrophage progenitors and the behavior of monocytes/macrophages, indicating that BM-AT 1 could be a promising therapeutic target for the prevention of cardiovascular events.

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Angiotensin II Regulates Th1 T Cell Differentiation Through Angiotensin II Type 1 Receptor-PKA-Mediated Activation of Proteasome

Cellular Physiology and Biochemistry ◽

10.1159/000487562 ◽

2018 ◽

Vol 45 (4) ◽

pp. 1366-1376 ◽

Cited By ~ 13

Author(s):

Xian-Yun Qin ◽

Yun-Long Zhang ◽

Ya-Fei Chi ◽

Bo Yan ◽

Xiang-Jun Zeng ◽

...

Keyword(s):

Cell Differentiation ◽

Angiotensin Ii ◽

Ubiquitin Proteasome System ◽

Jurkat Cells ◽

Pcr Analysis ◽

Mrna Levels ◽

Dependent Manner ◽

Ang Ii ◽

Th1 Cell

Background/Aims: Naive CD4+ T cells differentiate into T helper cells (Th1 and Th2) that play an essential role in the cardiovascular diseases. However, the molecular mechanism by which angiotensin II (Ang II) promotes Th1 differentiation remains unclear. The aim of this study was to determine whether the Ang II-induced Th1 differentiation regulated by ubiquitin-proteasome system (UPS). Methods: Jurkat cells were treated with Ang II (100 nM) in the presence or absence of different inhibitors. The gene mRNA levels were detected by real-time quantitative PCR analysis. The protein levels were measured by ELISA assay or Western blot analysis, respectively. Results: Ang II treatment significantly induced a shift from Th0 to Th1 cell differentiation, which was markedly blocked by angiotensin II type 1 receptor (AT1R) inhibitor Losartan (LST). Moreover, Ang II significantly increased the activities and the expression of proteasome catalytic subunits (β1, β1i, β2i and β5i) in a dose- and time-dependent manner. However, Ang II-induced proteasome activities were remarkably abrogated by LST and PKA inhibitor H-89. Mechanistically, Ang II-induced Th1 differentiation was at least in part through proteasome-mediated degradation of IκBα and MKP-1 and activation of STAT1 and NF-κB. Conclusions: This study for the first time demonstrates that Ang II activates AT1R-PKA-proteasome pathway, which promotes degradation of IκBα and MKP-1 and activation of STAT1 and NF-κB thereby leading to Th1 differentiation. Thus, inhibition of proteasome activation might be a potential therapeutic target for Th1-mediated diseases.

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Angiotensin II induces apoptosis in rat glomerular epithelial cells

AJP Renal Physiology ◽

10.1152/ajprenal.00240.2001 ◽

2002 ◽

Vol 283 (1) ◽

pp. F173-F180 ◽

Cited By ~ 115

Author(s):

Guohua Ding ◽

Krishna Reddy ◽

Aditi A. Kapasi ◽

Nicholas Franki ◽

Nora Gibbons ◽

...

Keyword(s):

Transforming Growth Factor ◽

Time Dependent ◽

Receptor Type ◽

Dependent Manner ◽

Ang Ii ◽

Glomerular Epithelial Cells ◽

Induced Apoptosis ◽

Tgf Β1

ANG II has been shown to modulate kidney cell growth and contribute to the pathobiology of glomerulosclerosis. Glomerular visceral epithelial cell (GEC) injury or loss is considered to play a pivotal role in the initiation and progression of glomerulosclerosis. In the present study, we investigated the effect of ANG II on GEC apoptosis. Rat GECs were incubated with increasing doses of ANG II for variable time periods. Apoptosis was evaluated by cell nucleus staining and DNA fragmentation assay. ANG II induced GEC apoptosis in a dose- and time-dependent manner. The proapoptotic effect was attenuated by the ANG II receptor type 1 antagonist losartan or the ANG II receptor type 2 antagonist PD-123319 and was completely blocked by incubation with the combined antagonists. Moreover, ANG II stimulated transforming growth factor (TGF)-β1 production as measured by ELISA. GECs exposed to TGF-β1 demonstrated a dose- and time-dependent increase in apoptosis. ANG II-induced apoptosis was significantly inhibited by addition of anti-TGF-β1 antibody. ANG II also upregulated the expression of Fas, FasL, and Bax and downregulated the expression of Bcl-2 in GECs. These studies suggest that ANG II induces GEC apoptosis by a mechanism involving TGF-β1 expression that may, importantly, contribute to the pathogenesis of glomerulosclerosis.

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Angiotensin II plays a critical role in diabetic pulmonary fibrosis most likely via activation of NADPH oxidase-mediated nitrosative damage

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.00629.2010 ◽

2011 ◽

Vol 301 (1) ◽

pp. E132-E144 ◽

Cited By ~ 34

Author(s):

Junling Yang ◽

Yi Tan ◽

Fenglian Zhao ◽

Zhongsen Ma ◽

Yuehui Wang ◽

...

Keyword(s):

Angiotensin Ii ◽

Nadph Oxidase ◽

Lung Fibrosis ◽

Critical Role ◽

Receptor Expression ◽

Lung Fibroblasts ◽

Dependent Manner ◽

Ang Ii ◽

Diabetic Mice

Diabetic patients have a high risk of pulmonary disorders that are usually associated with restrictive impairment of lung function, suggesting a fibrotic process (van den Borst B, Gosker HR, Zeegers MP, Schols AM. Chest 138: 393–406, 2010; Ehrlich SF, Quesenberry CP Jr, Van Den Eeden SK, Shan J, Ferrara A. Diabetes Care 33: 55–60, 2010). The present study was undertaken to define whether and how diabetes causes lung fibrosis. Lung samples from streptozotocin-induced type 1 diabetic mice, spontaneously developed type 1 diabetic OVE26 mice, and their age-matched controls were investigated with histopathological and biochemical analysis. Signaling mechanism was investigated with cultured normal human lung fibroblasts in vitro. In both diabetes models, histological examination with Sirius red and hemotoxylin and eosin stains showed fibrosis along with massive inflammatory cell infiltration. The fibrotic and inflammatory processes were confirmed by real-time PCR and Western blotting assays for the increased fibronectin, CTGF, PAI-1, and TNFα mRNA and protein expressions. Diabetes also significantly increased NADPH oxidase (NOX) expression and protein nitration along with upregulation of angiotensin II (Ang II) and its receptor expression. In cell culture, exposure of lung fibroblasts to Ang II increased CTGF expression in a dose- and time-dependent manner, which could be abolished by inhibition of superoxide, NO, and peroxynitrite accumulation. Furthermore, chronic infusion of Ang II to normal mice at a subpressor dose induced diabetes-like lung fibrosis, and Ang II receptor AT1 blocker (losartan) abolished the lung fibrotic and inflammatory responses in diabetic mice. These results suggest that Ang II plays a critical role in diabetic lung fibrosis, which is most likely caused by NOX activation-mediated nitrosative damage.

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Lipid signal transduction pathways in angiotensin II type 1 receptor-transfected fibroblasts

AJP Cell Physiology ◽

10.1152/ajpcell.1995.269.2.c435 ◽

1995 ◽

Vol 269 (2) ◽

pp. C435-C442 ◽

Cited By ~ 19

Author(s):

Y. Wen ◽

M. C. Cabot ◽

E. Clauser ◽

S. L. Bursten ◽

J. L. Nadler

Keyword(s):

Signal Transduction ◽

Angiotensin Ii ◽

Chinese Hamster ◽

Receptor Activation ◽

Signal Transduction Pathways ◽

Ang Ii ◽

Vascular Type ◽

Lipid Signal ◽

Fibroblast Line

A stable Chinese hamster ovary fibroblast line expressing the rat vascular type 1a angiotensin II (ANG II) receptor was used to study the lipid-derived signal transduction pathways elicited by type 1a ANG II receptor activation. ANG II caused a biphasic and dose-dependent increase in diacylglycerol (DAG) accumulation with an initial peak at 15 s (181 +/- 11% of control, P < 0.02) and a second sustained peak at 5-10 min (214 +/- 10% of control, P < 0.02). The late DAG peak was derived from phosphatidylcholine (PC), and the formation was blocked by ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid. ANG II also increased phosphatidic acid (PA) production nearly fourfold by 7.5 min. In the presence of ethanol, ANG II markedly increased phosphatidylethanol (PEt) formation, indicating activation of phospholipase D (PLD). ANG II was shown to increase the mass of three separate PA species, one of which apparently originated from DAG kinase action on PC-phospholipase C (PLC)-produced DAG, providing evidence for PC-PLC activity. ANG II also formed a third PA species, which originated neither from PLD nor from DAG kinase. These results demonstrate that multiple lipid signals propagated via collateral stimulation of PLC and PLD are generated by specific activation of the vascular type 1a ANG II receptor.

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Modulation of Ca2+ transients in neonatal and adult rat cardiomyocytes by angiotensin II and endothelin-1

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1996.270.3.h857 ◽

1996 ◽

Vol 270 (3) ◽

pp. H857-H868 ◽

Cited By ~ 5

Author(s):

R. M. Touyz ◽

J. Fareh ◽

G. Thibault ◽

B. Tolloczko ◽

R. Lariviere ◽

...

Keyword(s):

Angiotensin Ii ◽

Receptor Agonist ◽

Dependent Manner ◽

Induced Responses ◽

Ang Ii ◽

Binding Studies ◽

Vasoactive Peptides ◽

Adult Cardiomyocytes ◽

Etb Receptor ◽

Dose Dependent

Vasoactive peptides may exert inotropic and chronotropic effects in cardiac muscle by modulating intracellular calcium. This study assesses effects of angiotensin II (ANG II) and endothelin-1 (ET-1) on intracellular free calcium concentration ([Ca2+]i) in cultured cardiomyocytes from neonatal and adult rats. [Ca2+]i was measured microphotometrically and by digital imaging using fura 2 methodology. Receptor subtypes through which these agonists induce responses were determined pharmacologically and by radioligand binding studies. ANG II and ET-1 increased neonatal atrial and ventricular cell [Ca2+]i transients in a dose-dependent manner. ANG II (10(-11) to 10(-7) M) failed to elicit [Ca2+]i responses in adult cardiomyocytes, whereas ET-1 increased [Ca2+]i in a dose-dependent manner. The ETA receptor antagonist BQ-123 significantly reduced (P 7< 0.05) ET-1 induced responses, and the ETB receptor agonist IRL-1620 (10(-7) to 10(-5) M) significantly increased (P < 0.05) [Ca2+]i in neonatal and adult cardiomyocytes. ET-1 binding studies demonstrated 85% displacement by BQ-123 and approximately 15% by the ETB receptor agonist sarafotoxin S6c, suggesting a predominance of ETA receptors. Competition binding studies for ANG II failed to demonstrate significant binding on adult ventricular myocytes, indicating the absence or presence of very few ANG II receptors. These data demonstrate that ANG II and ET-1 have stimulatory [Ca2+]i effects on neonatal cardiomyocytes, whereas in adult cardiomyocytes, ANG II-induced effects are insignificant, and only ET-1-induced responses, which are mediated predominantly via ETA receptors, are preserved. Cardiomyocyte responses to vasoactive peptides may thus vary with cardiac development.

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Reactive Oxygen Species-Mediated Homologous Downregulation of Angiotensin II Type 1 Receptor Mrna by Angiotensin II

Hypertension ◽

10.1161/hyp.36.suppl_1.688-b ◽

2000 ◽

Vol 36 (suppl_1) ◽

pp. 688-688

Author(s):

Toshihiro Ichiki ◽

Kotaro Takeda ◽

Akira Takeshita

Keyword(s):

Reactive Oxygen Species ◽

Angiotensin Ii ◽

Nadph Oxidase ◽

Mrna Expression ◽

Crucial Role ◽

Oxygen Species ◽

Ang Ii ◽

Stimulation Of

58 Recent studies suggest a crucial role of reactive oxygen species (ROS) for the signaling of Angiotensin II (Ang II) through type 1 Ang II receptor (AT1-R). However, the role of ROS in the regulation of AT1-R expression has not been explored. In this study, we examined the effect of an antioxidant on the homologous downregulation of AT1-R by Ang II. Ang II (10 -6 mol/L) decreased AT1-R mRNA with a peak suppression at 6 hours of stimulation in rat aortic vascular smooth muscle cells (VSMC). Ang II dose-dependently (10 -8 -10 -6 ) suppressed AT1-R mRNA at 6 hours of stimulation. Preincubation of VSMC with N-acetylcysteine (NAC), a potent antioxidant, almost completely inhibited the Ang II-induced downregulation of AT1-R mRNA. The effect of NAC was due to stabilization of the AT1-R mRNA that was destabilized by Ang II. Ang II did not affect the promoter activity of AT1-R gene. Diphenylene iodonium (DPI), an inhibitor of NADH/NADPH oxidase failed to inhibit the Ang II-induced AT1-R mRNA downregulation. The Ang II-induced AT1-R mRNA downregulation was also blocked by PD98059, an extracellular signal-regulated protein kinase (ERK) kinase inhibitor. Ang II-induced ERK activation was inhibited by NAC as well as PD98059 whereas DPI did not inhibit it. To confirm the role of ROS in the regulation of AT1-R mRNA expression, VSMC were stimulated with H 2 O 2 . H 2 O 2 suppressed the AT1-R mRNA expression and activated ERK. These results suggest that production of ROS and activation of ERK are critical for downregulation of AT1-R mRNA. The differential effect of NAC and DPI on the downregulation of AT1-R mRNA may suggest the presence of other sources than NADH/NADPH oxidase pathway for ROS in Ang II signaling. Generation of ROS through stimulation of AT1-R not only mediates signaling of Ang II but may play a crucial role in the adaptation process of AT1-R to the sustained stimulation of Ang II.

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Abstract P059: A A Role of Aminopeptidase A in the Brain on Cardiovascular Regulation of Conscious Rat

Hypertension ◽

10.1161/hyp.66.suppl_1.p059 ◽

2015 ◽

Vol 66 (suppl_1) ◽

Author(s):

Takuto Nakamura ◽

Masanobu Yamazato ◽

Akio Ishida ◽

Yusuke Ohya

Keyword(s):

Blood Pressure ◽

Protein Expression ◽

Drinking Behavior ◽

Cardiovascular Regulation ◽

Ang Ii ◽

Hypertensive Rats ◽

Aminopeptidase A ◽

The Brain

Objective: Aminopeptidase A (APA) have important role in conversion of Ang II to Ang III. Intravenous APA administration lowers blood pressure in hypertensive rats. In contrast, APA inhibition in the brain lowers blood pressure in hypertensive rats. Therefore APA might have different role on cardiovascular regulation. However, a role of APA and Ang III on cardiovascular regulation especially in the brain has not been fully understood. Our purpose of present study was to investigate a role of APA and Ang III in the brain on cardiovascular regulation in conscious state. Method: 12-13 weeks old Wistar Kyoto rat (WKY) and 12-16 weeks old spontaneously hypertensive rat (SHR) were used. i) APA distribution in the brain was evaluated by immunohistochemistry. Protein expression of APA was evaluated by Western blotting. Enzymatic activity of APA was evaluated using L-glutamic acid γ-(4-nitroanilide) as a substrate. ii) WKY received icv administration of Ang II 25ng/2μL and Ang III 25ng/2μL. We recorded change in mean arterial pressure (MAP) in conscious and unrestraied state and measured induced drinking time. iii) SHR received icv administeration of recombinant APA 400ng/4μL. We recorded change in MAP in conscious and unrestraied state and measured induced drinking time. Result: i) APA was diffusely immunostained in the cells of brain stem including cardiovascular regulatory area such as rostral ventrolateral medulla. Protein expression and APA activity in the brain were similar between WKY (n=3) and SHR (n=3).ii) Icv administration of Ang II increased MAP by 33.8±3.8 mmHg and induced drinking behavior for 405±90 seconds (n=4). Icv administration of Ang III also increased MAP by 24.7±2.4 mmHg and induced drinking behavior for 258±62 seconds (n=3). These vasopressor activity and induced drinking behavior was completely blocked by pretretment of angiotensin receptor type 1 blocker.iii) Icv administration of APA increased MAP by 10.0±1.7 mmHg (n=3). Conclusion: These results suggested that Ang III in the brain increase blood pressure by Angiotensin type 1 receptor dependent mechanism and APA in the brain may involved in blood pressure regulation as a vasopressor enzyme.

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