bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 624: Chronic High Fat Diet Increases Sodium Reabsorption and αENaC Expression Prior to the Onset of Hypertension in Dahl Salt-Sensitive Rats
Authors: Kemp Brandon A , Howell Nancy L , Gildea John J , Keller Susanna R , Padia Shetal H
Published: March 2022

An increase in distal nephron-dependent sodium (Na+) reabsorption plays a primary role in the development of obesity-induced hypertension. However, the specific Na+ transporter involved in this process is unknown. The present studies were undertaken to determine the role of the epithelial Na+ channel (ENaC) in the development of high fat-diet (HFD)-induced hypertension. Given that human obesity-induced hypertension is largely salt-sensitive, we chose to expose Dahl salt-sensitive (DSS) rats to either a chronic HFD (42% kcal from fat, normal salt, 0.25%, N=7)) or standard diet (STD, 10% kcal from fat, normal salt, 0.25%, N=7), measure blood pressures (BP) telemetrically, and collect 24 hr urine for Na+ each week, for 4 weeks. In a separate group of DSS rats, we isolated cortical collecting ducts for determination of αENaC protein expression at baseline, 1 week, and 4 weeks following STD or HFD. Telemetric systolic blood pressure (SBP) values increased significantly (P<0.05) from a baseline value of 118±2.7 mmHg to 135±4.4 mmHg after just 2 weeks on the HFD, and to 146.9±2.6 mmHg after 4 weeks (P<0.01). SBPs did not change in DSS rats on STD for the entire 4 weeks. Prior to the increase in BP, 24 hr urine Na+ excretion significantly decreased in DSS rats on HFD compared to STD (0.94±0.15 μmol/min vs. 1.35±0.09, P<0.05). Furthermore, compared to baseline, αENaC protein levels significantly increased after 1 week of HFD [0.93±0.13 and 0.51±0.02 densitometric units (DU) respectively, P<0.01], but not after 1 week of STD (0.46±0.02 DU). Following 4 weeks of HFD, αENaC protein levels remained significantly elevated (0.66±0.05 DU; P<0.05) compared to baseline. These results suggest that increased cortical collecting duct αENaC protein expression may contribute to the reduction in Na+ excretion that initiates the hypertensive cascade in HFD-induced hypertension.
Abstract 626: Differential Regulation of Blood Pressure in Transgenic Mice Containing two Haplotypes of Human Angiotensin Receptor Type 1
Authors: Jain Sudhir , Prater Alicia , Pandey Varunkumar , Arudra Srikrishna , Mopidevi Brahmaraju , Maharjan Shreekrishna , Kumar Ashok
Published: March 2022

The renin angiotensin system (RAS) is the main regulator of blood pressure and fluid homeostasis. Most of the known physiological and pathophysiological action of RAS are mediated through the angiotensin receptor type 1 (AT
1
R). Dose dependent increase in AT
1
R gene increases blood pressure in transgenic mice. Human AT
1
R gene promoter has four single nucleotide polymorphisms (SNPs) ( T/A at -777, T/G at -680, A/C at -214, and A/G at -119). Our studies have shown that variants -777T, -680T, -214A, and -119A almost always occur together in Caucasian subjects, creating haplotype I (TTAA) and II (AGCG) respectively. We have analyzed the genomic DNA from 388 normotensive and 374 hypertensive subjects and shown that haplotype I of the h AT
1
R gene is associated with hypertension in Caucasian subjects (p=< 0.001, χ
2
= 12.26). Our transient transfection studies in adrenal cortical (H295R) and vascular smooth muscle (VSMC) cells show that haplotype I of h AT
1
R gene has increased basal and induced promoter activity as compared to haplotype II. Our gel shift assays have shown that transcription factor USF-2, C/EBP beta and delta bind strongly to an oligonucleotide containing nucleoside A at -214 (present in haplotype-I). In order to understand the physiological effect of these haplotypes in an
in vivo
situation, we have generated transgenic mice containing 160Kb long BAC DNA (containing 67Kb of the 5’-flanking region, all five exons and four introns, and 44 Kb of the 3’-UTR of hAT
1
R gene) and differ only in 1.2Kb promoter containing either haplotype I or haplotype II. Our studies show that 8 weeks old male transgenic mice containing haplotype I have increased h AT
1
R mRNA level in the kidney (5.5 fold) and heart (3.7 fold) as compared to haplotype II. We also show that transgenic mice containing haplotype-I have increased systolic blood pressure (7 mmHg) as compared to transgenic mice containing haplotype II. Our results suggest that increased expression of haplotype I of the hAT
1
R gene may be a contributing factor for hypertension in Caucasian subjects.
Abstract 628: Renin Does not Participate in the Production of Plasma Ang-(1-12) from Angiotensinogen
Authors: Simington Stephen W , Moniwa Norihito , Ahmad Sarfaraz , VonCannon Jessica L , Dell'Italia Louis J , Varagic Jasmina , Ferrario Carlos M
Published: March 2022

Angiotensin-(1-12) [Ang-(1-12)] is an extended form of Ang I capable of generating Ang II via angiotensin converting enzyme and chymase. To date no study has addressed the identity of the enzyme or enzymes that accounts for the formation of Ang-(1-12) from the native angiotensinogen (Aogen) substrate. With this in mind, we investigated whether renin is involved in the metabolism of a shorter form of Aogen, [Ang-(1-20)] into the downstream angiotensin peptides. Two groups of male WKY rats (age 12 weeks) received a 15 min intravenous infusion of either saline vehicle (n= 4) or synthetic Ang-(1-20) (n = 5, 20nmol/kg/min) while a third set of rats (n = 5) were administered the Ang-(1-20) 48 h after bilateral Nephrectomy (NTX). Arterial blood was rapidly collected at the end of the infusion period for RIA measurements of angiotensin peptides. Administration of Ang-(1-20) was associated with prompt increases in mean arterial pressure that at 5 min within the infusion period were equivalent in magnitude in both intact (58 ± 2 mm Hg) and anephric (56 ± 3 mm Hg) rats (P > 0.05). Similarly, in intact and anephric rats, Ang-(1-20) metabolism resulted in marked increases in plasma Ang-(1-12) (255-fold and 285-fold higher, respectively; p<0.0001) and Ang II concentrations (82-fold and 97-fold higher, respectively; p<0.0001) compared to the corresponding values in intact vehicle-treated rats. The study demonstrates that renal renin is not involved in the cleavage of Ang-(1-12) from angiotensinogen since the magnitude of the pressor response and Ang-(1-12) and Ang II generation during administration of Ang-(1-20) were not significantly different in intact and anephric rats. Moreover, in a pilot
in vitro
study, a 15 minutes incubation of plasma from NTX rats with and without aprotinin (kallikrein inhibitor; 20μM) revealed a higher plasma concentration of Ang-(1-12) (2.5-fold) when aprotinin was absent from the inhibitory cocktail. These data further suggest a contributory role of a member of the kallikrein family as the enzyme accounting for the cleavage of Ang-(1-12) from Aogen.
Abstract 633: Lack of ACE2 Abolishes High Fat Diet-Induced Upregulation of Prolyl Carboxypeptidase
Authors: Leiva Orly , Grobe Nadja , Weir Nathan M , Neff Valerie , Elased Khalid M , Morris Mariana
Published: March 2022

Emerging evidence suggests that activation of the proteases, Ang converting enzyme 2 (ACE2) and prolyl carboxypeptidase (PCP), are associated with metabolic pathologies. We hypothesized that global loss of ACE2 affects high fat diet induced renal expression of PCP. ACE2 knockout (ACE2KO) and wild type (WT) male mice were fed a 60% high fat (HF) or normal chow (NC) diet for 12 weeks. Using dual immunofluorescence microscopy and western blotting, we determined the expression pattern and abundance of ACE2 and PCP in kidney. PCP was co-localized with ACE2 in the Bowman’s capsule of the glomerulus. PCP was also localized along the apical membrane of proximal tubules along with ACE2. There was no evidence for protease co-localization in the tubules. ACE2 was absent in kidney from ACE2KO (immunofluorescence or western). PCP localization was unchanged in ACE2KO and the localization of both proteases did not change in response to HF diet. Protein intensity, normalized to ß-actin, showed no difference in PCP between untreated WT and KO (0.76±0.18 vs 0.57±0.07). PCP in HF WT was significantly elevated as compared to HF KO (0.94±0.02 vs 0.57±0.03, p≤0.05) while HF WT ACE2 levels remained unchanged as compared to untreated WT (0.90±0.24 vs 0.94±0.16). Results indicate loss of ACE2 negatively affects HF diet-induced PCP expression. Neither the absence of ACE2 nor HF diet changed the localization of PCP. These results suggest interactions between ACE2 and PCP in metabolic pathologies.
Abstract 635: Knockdown Of Tyrosine Hydroxylase In The Nucleus Of The Solitary Tract (NTS) Reduces Persistent Increase In Blood Pressure During Chronic Intermittent Hypoxia (CIH)
Authors: Bathina Chandra S , Rajulapati Anuradha , Franzke Michelle , Yamamoto Kenta , Mifflin Steve
Published: March 2022

A2 neurons in caudal NTS express tyrosine hydroxylase (TH), the rate-limiting enzyme in catecholamine synthesis, and respond to stressors such as hypoxia. We tested the hypothesis that TH knockdown in NTS reduces cardiovascular responses to CIH, an animal model that mimics the arterial hypoxemia observed during sleep apnea in humans. Adult male Sprague-Dawley rats were implanted with radiotelemetry transmitters and adeno-associated viral constructs (GeneDetect, Inc) with a GFP reporter having either short hair-pin RNA for TH (shRNA) or scrambled virus (scRNA) were injected into caudal NTS. A group of no injection, no CIH (control) rats were also used. Baseline mean arterial pressure (MAP) and heart rate (HR) were collected from all 3 groups for at least 4 days after which the virus injected rats were exposed to 7 days CIH (alternating 3 min periods of 10% O2 and 21% O2 from 8am to 4pm; from 4pm to 8am the rats were exposed to 21% O2). In shRNA injected rats (n=9) 7 day exposure to CIH increased MAP and HR during the day by 6.6±1.8 mmHg and 49.9±7.7 bpm and during the night by 0.3±1.8 mmHg and -4.5±1.3 bpm compared to baseline. In scRNA injected rats (n=10) 7 day exposure to CIH increased MAP and HR during the day by 7.7±1.2 mmHg and 65.3±7.9 bpm and during the night by 4.8±1.5 mmHg and 0.0±4.9 bpm compared to baseline. In control rats (n=8) MAP and HR were 1.5±1.0 mmHg and -8.4±3.8 bpm during the day and 1.8±0.9 mmHg and -10.8±2.9 bpm during the night compared to baseline. CIH induced significant changes in MAP and HR during the day in both the scRNA (p=.006 MAP; p<.001 HR) and shRNA (p=.007 MAP; p<.001 HR) groups. Compared to control rats, during the night CIH induced significant changes in MAP in the scRNA rats (p=0.02) but not in the shRNA group and no significant changes in HR in either group. The number of TH-immunoreactive neurons was reduced by 20% in sections with GFP fluorescence; shRNA 28±1 cells/section compared to scRNA 35±1 cells/section (p=.005). CIH induces an increase in MAP that persists beyond the period of exposure to CIH. Knockdown of TH in the NTS reduces this persistent increase in MAP induced by exposure to CIH. This indicates that NTS A2 neurons play a role in the cardiovascular responses to CIH and suggests they may play a similar role in the pathology of sleep apnea in humans.
Abstract 636: Angiotensin II-Mediated Endothelial Cell Dysfunction Contributes to Adipocyte Stem Cell Dysfunction and Adiposity
Authors: Carroll Trevor , Kim Dong Hyun , Sodhi Komal , Puri Nitin , Peterson Stephen J , Drummond George , Cheng Pao-Yun , Abraham Nader G
Published: March 2022

Rationale:
Crosstalk between perivascular adipose tissue and endothelial cells has been proposed to modulate vascular homeostasis. However, paracrine regulatory effects of the stressed endothelium on adipose tissue are relatively unknown.

Objective:
We examined the hypothesis that redox mechanisms in endothelial cells can regulate adipocyte function, in a paracrine fashion, via suppression of the Wnt10b/β-catenin-dependent pathways.

METHODS:
Human umbilical vein endothelial cells (HUVEC) were treated with AngII (1-50 μM) in the absence and in the presence of the heme oxygenase (HO-1) inducer_cobalt protoporphyrin (CoPP)_or to HO-1 activity inhibitor_stannous mesoporphyrin (SnMP). Adipogenesis was then induced in mesenchymal stem cells, in the presence (10%) or absence of conditioned media (CM) from HUVECs.

Results:
MSCs exposed to CM from AngII-treated HUVEC displayed enhanced adipogenesis (0.026±0.001 vs. 0.031±0.001, n=6, p<0.0405). This effect was reversed in MSCs supplemented with CM from HUVECs treated with AngII and CoPP (0.021±0.001, n=6, p<0.0024). This beneficial effect of CoPP in MSCs exposed to CM is reversed by SnMP (0.030±0.001, n=6, p<0.0462) and corroborates the ability of HO-1 in attenuating AngII-dependent adipocyte dysfunction. Complementary immunoblot analysis showed an attenuative effect of AngII on Wnt10b and β-catenin expression (p<0.05). Additionally, AngII enhanced the expression of adipogenic regulators including PPARY, CEBPα, and aP2, which was decreased by CoPP and increased by SnMP.

Conclusion:
Our results show that EC dysfunction, as a result of treatment with AngII, contributes to increased adipogenesis in MSCs by the release of negative regulators of adipogenesis. We also show that up-regulation of antioxidant HO-1 ameliorates these effects of AngII. This novel observation suggests that paracrine crosstalk between HUVECs and adipocytes increases endothelial stress to affect adipocyte structure and function. These phenomena might contribute to the metabolic imbalance frequently encountered in conditions associated with chronic endothelial dysfunction and adiposity.
Abstract 641: Effects of High Salt on the Sexual Dimorphism of Genes Encoding Epigenetic Chromatin Modification Enzymes in the Sprague-dawley Rat Kidney
Authors: Bourgeois Camille R , Satou Ryousuke , Rands Vicky F , Prieto Minolfa C
Published: March 2022

Young female humans and animals are protected from the development of hypertension and related end-organ damage when compared to age-matched males. We recently showed that high salt (HS) worsened preexisting hypertension and renal injury to a greater extent in Sprague-Dawley (SD) male than female rats. It has been shown that epigenetic modifications can contribute to hypertension and that HS increases the correlation between histone and DNA modifications and gene expression. However, it remains unclear if HS diet is the leading cause of these epigenetic modifications, thereby increasing the predisposition to hypertension. We hypothesize that HS consumption exacerbates sex disparity in the expression of chromatin modification genes, explaining the gender disparity in the susceptibility to hypertension. To test this hypothesis we used SD rats (7±1 week of age), a model of non-sensitive salt hypertension to minimize the influence of genetic susceptibility. We determined the expression levels of chromatin modification genes in male and female rats and the effects of HS diet (8% NaCl for 2-weeks) on the epigenetic changes. We used cDNAs that were prepared from RNA samples extracted from kidney cortexes and PCR array to screen 84 rat epigenetic chromatin modification enzyme genes (RT
2
Profiler PCR Array, QIAGEN, Inc, Valencia, CA). Analysis of 9 genes (
Aof1, AurkA, AurkB, AurkC, Hdac9, Pak1, Setd6, Smyd3
and
Suv420h2
) showed different expression levels between sexes, and these were further altered by HS diet. Importantly, the histone deacetylase 9 (
Hdac9
) gene was expressed significantly higher in the female controls compared to males (p<0.05); however, this difference decreased in response to HS diet.
Hdac9
has recently been reported to be associated with a high risk for hypertension. We concluded that in the rat kidney the expression of genes involved in histone modification is sexually dimorphic and these genes are differentially altered by HS diet. Thus, the epigenetic effects of HS consumption may help to explain the mechanisms underlying the sexual disparities in genetic susceptibility to diseases with complex environment-gene interaction, such as hypertension.
Abstract 642: GPR30-Mediated Relaxation of Mesenteric Resistance Arteries is Diminished in Males and Aging Females
Authors: Lindsey Sarah H , da Silva Ariel , Silva Mauro S , Chappell Mark C
Published: March 2022

We previously reported that chronic activation of estrogen receptor GPR30 by the selective agonist G-1 decreases blood pressure in ovariectomized hypertensive mRen2.Lewis rats but not male littermates. Furthermore, acute G-1 relaxes female mesenteric resistance arteries via both endothelium-dependent and -independent mechanisms. Because of the lack of a blood pressure-lowering effect by G-1 in males and because aging may influence estrogen receptor expression, we hypothesized that GPR30-dependent vasodilation was reduced in males and older females. Mesenteric vessels (∼200 μm I.D.) from 15 wk Lewis and mRen2.Lewis males and 52 wk Lewis females were mounted on a wire myograph and preconstricted with 10 μM phenylephrine before assessing the response to increasing concentrations of 17β-estradiol or G-1 (0.001-3 μM). At the highest concentration, 17β-estradiol vasodilation was greater in 15 wk Lewis females (62±8%, n=5) and mRen2.Lewis females (57±9%, n=6) than age-matched Lewis males (33±7%, n=5, P<0.001) and mRen2.Lewis males (30±7%, n=4, P<0.001). The G-1 response was also greater in Lewis females (60±12%, n=7) and mRen2.Lewis females (57±8%, n=5) than in Lewis males (33±8%, n=7, P<0.01) and mRen2.Lewis males (28±7%, n=4, P<0.01). Pretreatment of male vessels with the nitric oxide (NO) synthase inhibitor L-NAME had no significant effect on the estradiol or G-1 response (n=3-6, P>0.05). In aged females, vasorelaxation was also significantly blunted in response to 17β-estradiol (34±6%, n=5, P<0.01) and G-1 (32±6%, n=8, P<0.01). In contrast to males, L-NAME inhibition or endothelial denuding in older females further reduced vasodilation to both 17β-estradiol (L-NAME: 15±6%, n=4, P<0.05; denuded: 13±2%, n=8, P<0.001) and G-1 (L-NAME: 10±6%, n=3, P<0.01; denuded 8±2%, n=11, P<0.0001). In summary, GPR30-mediated vasodilation was attenuated in Lewis and mRen2.Lewis males, and the ineffectiveness of L-NAME inhibition suggests a loss in NO signaling. G-1 vasorelaxation was also blunted in aging Lewis females, but the intact NO response indicates a smooth muscle cell deficit. We conclude that alterations in GPR30 expression or signaling may contribute to the loss of cardiovascular protection in aging postmenopausal females and in adult males.
Abstract 658: Pressor And Sympathetic Response To 2% Saline Augmented By Prior Treatment With Intracerebroventricular (icv) Angiotensin II (ANGII)
Authors: Clayton Sarah C , Xue Baojian , Zhang Zhangming , Johnson Alan K
Published: March 2022

Previous studies from our laboratory demonstrate that the sensitizing effects of sub-pressor ANGII or aldosterone treatments on ANGII-induced hypertension are mediated through the CNS. The present study tested if pressor response sensitization extends to another hypertensive challenge, 2% saline given as the sole drinking fluid. The study followed an Induction-Delay-Expression (
I-D-E
) experimental design. We instrumented rats with telemetry devices to continuously record blood pressure (BP) and heart rate throughout the experiments. After one week recovery and one week baseline (
B
) recording, rats underwent a second surgery to implant icv cannulas to continuously deliver ANGII (1 ng/kg/min; prior ANGII) or vehicle (control) for one week (
I
). After
I
and after a 1 week
D
, drinking water was switched to 2% saline (
E
). The degree of autonomic tone was assessed via ganglionic blockade (hexamethonium, 30 mg/kg, ip) during
B
, after
I
, and during
E
. During
B,
group BPs were not different (103±2 mmHg control vs. 107±4mmHg, prior-ANGII). Although drinking only 2% saline increased BPs in both groups (122±3 mmHg, control vs. 141±9 mmHg, prior-ANGII), the absolute increase was greater in rats treated with ANGII during
I
(19±3, control vs. 34±6, prior-ANGII, p<0.05). At
B,
control and prior-ANGII treated rats showed no difference in the depressor response to hexamethonium (-17±3%, control vs. -13±1%, prior-ANGII) or after
I
(-13±5%, control vs. -20±9%, prior-ANGII). However, during
E
while drinking2% saline, prior-ANGII treated rats displayed a significantly larger fall in BP to hexamethonium than controls (-20±5%, control vs. -36±7%, prior-ANGII, p<0.05), suggesting that during
E
a higher degree of sympathetic tone maintained BP in the prior-ANGII treated rats. These data show that icv treatment with ANGII sensitizes the hypertensive response induced by 2% saline intake and that this enhanced pressor effect is accompanied by elevated sympathetic tone. These results provide new insights into the etiology of salt-sensitive hypertension by implicating a role for ANGII-induced neuroplasticity in CNS systems controlling sympathetic tone.
Abstract 664: Vascular Smooth Muscle Toll-like Receptor-2 (tlr2) Is Upregulated During Hyperglycemia
Authors: Schmidt Luke , Carrillo-Sepulveda Maria Alicia , Nunes Kenia , Spitler Kathryn , Webb R Clinton
Published: March 2022

Hyperglycemia, the major initiator of diabetic vascular dysfunction, is related with heightened vascular contractility and inflammation. Toll-like receptor-2 (TLR2), a key effector of innate immunity, has recently emerged as a crucial mediator of proinflammatory signaling during diabetes; however, whether or not TLR2 is altered during diabetic vascular complications remains to be elucidated. We hypothesize that upregulation of TLR2 contributes to vascular dysfunction and inflammation in the aorta of diabetic rats. This study was performed in streptozotocin (STZ)-induced diabetic rats (65mg/kg; 5 weeks) and primary aortic vascular smooth muscle cell (VSMC) cultures stimulated with high glucose (HG; 25mM),
in vivo
and
in vitro
models of hyperglycemia, respectively. To confirm the diabetic vascular dysfunction condition, myograph studies were performed. The results showed that thoracic aortic rings from STZ-induced diabetic rats have increased contractile response to phenylephrine (PE, 1ηM to 0.1mM) compared to control (E
max
206.20%±8.99% vs 98.41%±3.65%, respectively). TLR2 was increased significantly in the aorta from STZ-induced diabetic rats (1.8 fold vs. control) and in aortic VSMCs stimulated with HG for 6 hours (1.5 fold vs control). Elevated tumor necrosis factor α (TNF-α) and decreased interleukin-10 (IL-10) protein levels confirmed the proinflammatory state of aortas from STZ-diabetic rats (2.5 and 0.4 fold vs. control, respectively). Furthermore, expression of MyD88, a downstream adaptor protein for TLR2 signaling, is augmented significantly in diabetic aorta and aortic VSMCs under HG conditions (2.6 and 1.5 fold vs. control, respectively). Also, considering that protein kinase C (PKC) is a potential candidate of upstream activation of TLR2, we evaluated the expression the PKC isoforms. Our results show that PKCε is the only isoform increased significantly (1.7 fold vs. control). Our findings suggest that activating TLR2/MyD88 signaling pathway may play a role in mediating augmented proimflammatory response, which in turn contributes to vascular dysfunction during hyperglycemic conditions.
Abstract 72: Potentiation of Reparative Capacity of Cardiac Progenitor Cells (cpcs, Islet-1+) by Angiotensin-(1-7) in Myocardial Infarction (MI)-induced Cardiac Damage
Authors: Qi YanFei , Bruce Erin , Shenoy Vinayak , Jeffrey Colleen , Liu Meng , Yuan Wei , Lin Fan , Abbatematteo Joseph , Katovich Michael , Raizada Mohan
Published: March 2022

Background:
Endogenous myocardial regeneration is insufficient to fully rescue hemodynamic functions following MI. Stem cell therapy has been attempted to provide exogenous reparative support to ameliorate cardiac regeneration with limited success. We evaluated the hypothesis that transduction of CPCs with Ang-(1-7) would improve their reparative capacity, since this vasoprotective axis of the renin angiotensin system is implicated in progenitor cell functions.

Methods:
CPCs were isolated from adult rats, characterized by the presence of Islet-1 in the nuclei and expression of GATA4 and Nkx2-5. Their transduction with Lenti-Ang-(1-7) resulted in a 20-fold increase in Ang-(1-7) production. 4 × 10
6
of CPCs, or lenti-Ang-(1-7) transduced CPCs, were injected via the jugular vein three days after permanent left anterior descending coronary artery ligation. Echocardiography, hemodynamic, histological parameters, and capillary vessel density were measured to assess cardiac function and effects of cell transplantation four weeks thereafter.

Results:
First we determined if Ang-(1-7) improves CPC functions
in vitro
. Hypoxia inhibited the migration of CPCs, whereas Ang-(1-7) protected CPCs from hypoxia induced inhibition of migration. Results from the
in vivo
studies demonstrated that MI significantly reduced fractional shortening (FS, 33.0% ± 1.5 vs 59.5% ± 1.9 for control), increased ventricular hypertrophy (VH, 3.6 ± 0.1 vs 2.7 ± 0.1 for control, (g/kg)), and decreased dP/dt
max
(7235 ± 271.9 vs 10394 ± 326.3 for control, mmHg/sec). In comparison to MI, CPCs alone restored FS by 22%, reversed VH by 11%, and improved dP/dt
max
by 23%. Remarkably, Ang-(1-7) expressing CPCs further improved FS by 44%, decreased VH by 15%, and attenuated the reduction in dP/dt
max
by 42%. Finally, capillary density in the peri-infarct myocardium was increased by 59% with CPCs alone and this capillary density was further increased by 139% with Ang-(1-7) expressing CPCs.

Conclusions:
These observations, for the first time, demonstrate that Ang-(1-7) enhances CPC capacities to improve cardiac hemodynamic and circulation following MI. They suggest that Ang-(1-7) transduced CPC could be an improved stem cell therapy strategy for the treatment of ischemic heart disease.
Abstract 80: Central Rho Kinase Inhibition Lowers Sympathetic Nerve Activity and Restores Baroreflex Sensitivity and AT1R Protein Expression in Conscious Rabbits with Chronic Heart Failure
Authors: Haack Karla K , Gao Lie , Curry Pamela , Zucker Irving H
Published: March 2022

Rho-Associated protein kinase (RhoK) is a serine/threonine kinase involved in calcium sensitization and vascular smooth muscle cell contraction. RhoK overactivation is implicated in chronic heart failure (CHF) and a potential contributor to the heightened sympathetic nerve activity seen in CHF. Thus, we investigated the effect of central RhoK blockade on renal sympathetic nerve activity (RSNA) in a pacing rabbit model of CHF. CHF was induced by rapid ventricular pacing and characterized by an ejection fraction of ∼45%. Renal nerve recording electrodes, an ICV cannula and osmotic minipump (rate: 1 μL/h) containing sterile saline or 1.5 mg/kg/mL fasudil (Fas, a RhoK inhibitor) were implanted. Arterial baroreflex control was determined by IV infusion of sodium nitroprusside (100μg/kg) until mean arterial pressure (MAP) was lowered to ∼40 mmHg and phenylephrine (80μg/kg) until MAP was raised to ∼100 mm Hg. Fas infusion significantly lowered resting heart rate and improved maximal HR/MAP baroreflex gain in CHF (Fas:2.20 ± 0.13 vs Veh:2.84 ± 0.12). Administration of metoprolol prior to performing baroreflex analysis restored HR to sham levels and increased slope in the Fas group, suggesting Fas improves vagal tone. Change in RSNA response to oropharyngeal smoke was increased in CHF Fas animals vs CHF Veh. Fas decreased AT1R and phospho-RhoA (a readout of RhoK activity) protein expression and increased eNOS expression in the RVLM of CHF animals. These data suggest that central RhoK activation may contribute to sympatho-excitation in the setting of CHF and that Fas restores vagal tone and decreases sympathetic outflow. *p<0.05 vs sham groups, †p<0.05 vs Sham Fas, ‡p<0.05 vs CHF Veh.
Abstract 154: Knockdown of Mineralocorticoid or AT
1
Receptor Gene in the Paraventricular Nucleus Prevents Ang II Induced Hypertension in Rats
Authors: Chen Aidong , Huang Bing S , Wang Hongwei , Ahmad Monir , Leenen Frans H
Published: March 2022

Circulating Ang II activates an aldosterone-MR-AT
1
R pathway in the hypothalamus. To obtain insights into the actual aldosterone-MR- AT
1
R neuronal pathway, the present study examined whether intra-PVN infusion of AAV-AT
1a
R-siRNA or AAV-MR-siRNA prevents the Ang II induced increases in AT
1
R and MR expression and BP. Two weeks sc infusion of Ang II at 500ng/kg/min in Wistar rats on regular salt diet increased BP by telemetry by 66 ± 3 mm Hg, and AT
1
R and MR protein in the SFO, SON and PVN. Intra-PVN AT
1a
R-siRNA decreased AT
1
R but not MR expression in the PVN by sc Ang II, and MR-siRNA decreased MR but not AT
1
R expression in the PVN. AT
1
R and MR expression in both SFO and SON were not significantly changed by the two AAV-siRNA. Specific knockdown of AT
1
R or MR in the PVN by AAV-siRNA prevented ~80% of the increase in BP induced by sc Ang II. These results suggest that circulating Ang II up-regulates brain Ang II and aldosterone and increases MR and AT
1
R in the SFO, SON and PVN. Prevention of Ang II induced increases in MR but not AT
1
R by knockdown of MR and vice versa suggests an independent regulation of MR and AT
1
R in the PVN. Both AT
1
R and MR in the PVN play a critical role in Ang II-induced hypertension in rats.

* p<0.05 versus AAV-SCM alone. a: p<0.05 versus AAV-SCM + Ang II.
Abstract 161: The (Pro)renin Receptor Regulates Renin Release and Prorenin-to-Renin Conversion in (Pro)Renin-Synthesizing Human Mast Cells
Authors: Lu Xifeng , Krop Manne , Garrelds Ingrid M , van Gool Jeanette M , Jan Danser A H
Published: March 2022

The (pro)renin receptor ((P)RR), also known as ATP6AP2, is an accessory protein of the vacuolar H
+
-ATPase (V-ATPase), which is required for V-ATPase integrity and function. V-ATPases play an important role in acidifying intracellular compartments that are important for multiple cellular events such as proteolytic processing of proinsulin. To investigate whether the (P)RR affects prorenin-to-renin conversion, we studied the consequences of (P)RR knockdown in (pro)renin-synthesizing human mast cells (HMC-1). HMC-1 cells were transfected with siRNA against the (P)RR using Nucleofector
®
kit L with Amaxa
®
Nucleofector device, and the medium and cellular renin/prorenin content were measured by immunoradiometric assay (Cisbio, France) after 48, 72 and 96 hours (four experiments in duplicate). (P)RR siRNA (but not mock transfection or negative control siRNA) decreased the (P)RR protein levels by up to 95% from 18-96 hours after transfection. Renin medium levels amounted to 9.61.6, 13.13.3 and 14.54.1 pg/mg protein at 48, 72 and 96 hours, whereas the concomitant prorenin levels were 19.64.1, 31.510.4 and 36.811.1 pg/mg protein. Cells exclusively contained renin, and the renin content at 48 hours (28131 pg/mg protein) was not different from that at 72 and 96 hours. Whereas negative control siRNA did not affect these levels, (P)RR siRNA increased renin release at 72 and 96 hours 5-7-fold, and doubled the prorenin release at these time points. As a consequence, the % of total renin (=renin + prorenin) released by HMC-1 as renin doubled. No siRNA effects were noted on the cellular renin content. In conclusion, (P)RR knockdown affects both prorenin-renin conversion and (pro)renin release, resulting in a net rise of the renin/prorenin ratio in the medium.
Abstract 162: Possible Roles of Crosstalk Between Angiotensin-converting Enzyme 2/Angiotensin (1-7)/Mas Axis and Angiotensin (1-7)/angiotensin II Type 2 Receptor Axis in Vascular Remodeling
Authors: Ohshima Kousei , Mogi Masaki , Nakaoka Hirotomo , Iwanami Jun , Min Li-Juan , Tsukuda Kana , Kanno Harumi , Chisaka Toshiyuki , Wang Xiao-Li , Ogimoto Akiyoshi , Higaki Jitsuo , Horiuchi Masatsugu
Published: March 2022

Objectives:
Crosstalk between the angiotensin (Ang)-converting enzyme (ACE)/Ang II/ Ang II type 1 (AT
1
) receptor axis and ACE2/Ang (1-7)/Mas axis plays a role in the pathogenesis of cardiovascular remodeling. Moreover, possible stimulation of Ang II type 2 (AT
2
) receptor by Ang-(1-7) has been highlighted as new axis; however, pathophysiological significance of this possibility has to be elucidated in more detail. Therefore, we examined the possibility whether ACE2/Ang (1-7)/Mas axis and Ang (1-7)/AT
2
receptor axis is involved the inhibitory effects of AT
1
receptor blocker (ARB) on vascular remodeling.

Methods:
Ten-week-old male C57BL/6J (wild type: WT), Mas knockout (MasKO), and AT
2
receptor knockout (AT
2
KO) mice were used in this study. Vascular injury was induced by polyethylene-cuff placement around the mouse femoral artery. After cuff placement, some mice were treated with azilsartan (0.3 mg/kg/day), an ARB, or Ang (1-7) (0.5 mg/kg per day). Two weeks after operation, femoral arteries were removed, fixed and stained by Elastica van Gieson staining for evaluating neointimal formation.

Results:
Neointima formation induced by cuff placement was further increased in MasKO mice compared with WT mice. Treatment with azilsartan or Ang-(1-7) decreased neointima area and vascular smooth muscle cell proliferation, and attenuated the increases in the mRNA level of MCP-1, TNF-α and IL-1β in the injured artery in WT mice without influencing blood pressure. These inhibitory effects of azilsartan or Ang-(1-7) were less in Mas KO mice. One week after cuff placement, the mRNAs of ACE2 and Mas in the injured artery were markedly decreased in WT mice. Administration of azilsartan or Ang-(1-7) attenuated the decrease in ACE2 mRNA, but not affect the decrease in Mas mRNA. Neointima formation in AT
2
KO mice was more exaggerated compared with that in WT mice. Interestingly, we observed that inhibitory effect of Ang-(1-7) on neointima formation was less in AT
2
KO mice compared with WT mice.

Conclusion:
These results suggest that blockade of AT
1
receptor by azilsartan could enhance the activities of the ACE2/Ang (1-7)/Mas axis and ACE2/Ang-(1-7)/AT
2
receptor axis, thereby inhibiting the neointima formation.
Abstract 165: Defining the Cox-2/pge2/ep4,1 Pathway in Mediating Ang Ii-induced (pro)renin Receptor Expression in Primary Rat Inner Medullary Collecting Duct Cells
Authors: Wang Fei , Lu Xiaohan , Zhou Li , Li Chunling , Yang Tianxin
Published: March 2022

(Pro)rennin receptor (PRR) is a newly identified component of the renin-agiotensin system, being capable of binding to renin and its inactive precursor prorenin to activate renin and also triggering intracellular signaling involving ERK (extracellular-signal-regulated kinase) ½. Abundant expression of PRR was demonstrated in the collecting duct where it was stimulated by angiotensin II, which may serve as a positive feedback loop to amplify the local action of the RAS in the renal medulla. However, the mechanism of Ang II induced PRR expression in the collecting duct (CD) remains unknown. The goal here was to test whether cycloxygenase-2 (COX-2), an important regulator of renal medullary function, was involved in this phenomenon. Exposure of primary rat inner medullary collecting duct (IMCD) cells for 12 hours induced a parallel induction of PRR protein (mRNA: 1.10 ± 0.37; P=NS; protein: 1.43±0.08 fold change; P<0.05) and COX-2 mRNA and protein (mRNA: 1.34±0.15; P<0.05; protein: 1.34 ± 0.17 fold change; P<0.05), as assessed by immunoblotting and qRT-PCR. When the cells were pretreated with a specific COX-2 inhibitor NS-398, Ang II-induced upregulation of PRR protein expression was almost completely abolished. Treatment with exogenous PGE2 at 1 μM for 12 hours induced an 2.6-fold increase in PRR protein expression and also completely reversed inhibitory effect of NS-398 on Ang II-induced stimulation of PRR expression. To assess which EP receptor was involved in the PRR upregulation, we used specific EP receptor antagonists: SC-51382 (for EP1; 10 nmol/L), L-798106 (for EP3; 10 μmol/L) and L-161982 (for EP4; 10 μmol/L). The upregulation of PRR expression by Ang II was nearly abolished by L-161982, and partially suppressed by SC-51382, but was unaffected by L-798106. On the contrary, the COX-2 stimulation by Ang II was enhanced by L-161982, but was unaffected by SC-51382 or L-798106. We conclude that: 1) Ang II stimulates CD PRR expression via COX-2-derived PGE2 acting through EP4 and EP1 receptors, and 2) a negative feedback loop involving EP4-mediated inhibition of COX-2 expression exists to mitigate the exaggerated PRR response to Ang II in the distal nephron.
Abstract 17: Angiotensin-II-mediated Hypertension is Associated With ACE2 Internalization and Degradation in the Central Nervous System
Authors: Xia Huijing , Deshotels Matthew R , Filipeanu Catalin , Lazartigues Eric D
Published: March 2022

We previously observed that decreased brain ACE2 expression/activity contributes to the development of Angiotensin-II (Ang-II)-mediated hypertension in mice. To identify the mechanism involved in the impaired ACE2 expression/activity during hypertension, we first investigated ACE2 subcellular localization in the presence of Ang-II in vitro. Neuro2A cells (neuroblastoma) were transfected with a GFP-tagged human ACE2 plasmid construct (48 hours) and treated with Ang-II (100 nM, 4 hours). ACE2 localization was visualized with a flurorescence microscope (n=6), and protein levels on plasma membrane were determined by biotinylation followed by western blot (n=3). ACE2 expression was reduced at the plasma membrane and co-localized with the lysosomal marker Rab7 after Ang-II treatment, suggesting a translocation of ACE2 from plasma membrane to lysosomes. Biotinylation experiments confirmed a 50% reduction of plasma membrane ACE2 expression in Ang-II treated cells compared to vehicle group. To determine whether ACE2 internalization is responsible for the development of hypertension, C57Bl6 mice were implanted with telemetry probes for conscious blood pressure recording, and osmotic pumps for the following treatment groups: (n=6/group), 1) saline sc + aCSF icv; 2) Ang-II (600 ng/kg·min, sc, 14 days) + aCSF icv; 3) Ang-II + leupeptin (lysosomal inhibitor; 640 ng/kg·min, icv, 14 days); 4) saline sc + Leupeptin icv. After 2 weeks of treatment, leupeptin alone did not alter mean arterial blood pressure (MAP) compared to vehicle treatment (97±1
vs.
97±2 mmHg), however, it prevented Ang-II-mediated-increase in MAP (117±8 mmHg
vs.
135±10 mmHg,
P
<0.01). To test whether the leupeptin-mediated prevention of hypertension involved ACE2, we infused ACE2 knockout mice with Ang-II sc in the presence or absence of leupeptin icv. Interestingly, Ang-II-mediated increase in MAP in ACE2 knockout mice (131±8 mmHg) was not significantly changed by icv leupeptin infusion (125±8 mmHg), suggesting that leupeptin prevented hypertension by inhibiting brain ACE2 degradation. Our data suggest that Ang-II promotes ACE2 internalization and degradation in lysosomes, while prevention of ACE2 degradation by leupeptin reverses the development of hypertension.
Abstract 178: Cytosolic Phospholipase A
2
a in Brain Subfornical Organ is Critical for Angiotensin II-induced ER and Oxidative Stress and Hypertension
Authors: Song Chi Young , Khan Nayaab S , Fang Xiao R , Liao Francesca-Fang , Wang Bin , Bonventre Joseph V , Malik Kafait U
Published: March 2022

Angiotensin (Ang) II activates group IV cytosolic phospholipase A
2
α (cPLA
2
α) and releases arachidonic acid (AA) that is metabolized into pro-and antihypertensive eicosanoids. Ang II is also known to increase blood pressure via enhanced ER and oxidative stress in brain subfornical organ (SFO). These observations and our recent finding that Ang II-induced hypertension and associated cardiovascular dysfunction is ameliorated in cPLA
2
α knockout mice (cPLA
2
α
-/-
) led us to investigate the contribution of SFO cPLA
2
α in Ang II-induced ER and oxidative stress and hypertension. Ang II infusion (700ng/kg/min, s.c.) for 14 days increased systolic blood pressure (SBP) measured by tail cuff, in wild type (cPLA
2
α
+/+
) but not cPLA
2
α
-/-
mice (122 ± 2 to 177 ± 2 mmHg vs. 119 ± 4 to 125 ±1 mmHg, respectively, P<0.05). Ang II increased cPLA
2
activity, determined by immunohistochemistry using phospho-Ser505 antibody, in SFO of cPLA
2
α
+/+
but not cPLA
2
α
-/-
mice. Ang II also increased in SFO of cPLA
2
α
+/+
mice reactive oxygen species (ROS) production measured by dihydroethidium staining (5.09 ± 0.31 AU to 8.99 ± 0.33 AU, P<0.05), and expression of ER stress markers measured by RT-PCR (AU) GRP78 and CHOP (1.00 vehicle vs. 1.31 ± 0.09 and 1.79 ± 0.17 Ang II, respectively, P<0.05), but not in cPLA
2
α
-/-
mice. Transduction in cPLA
2
α
-/-
mice of SFO with adenovirus (Ad) (1x 10
12
pfu/0.5 μL) expressing Ad-enhanced fluorescence protein (ECFP) cPLA
2
α DNA but not control Ad-green fluorescence protein (GFP) DNA, restored the effect of Ang II to increase SBP and ROS production (121 ± 3.45 to 173 ± 2.54 mmHg and 4.40 ± 0.31 to 7.66 ± 0.47 AU with Ad-ECFP cPLA
2
α DNA vs. 121 ± 1 to 125 ± 4.07 mmHg and 4.04 ± 0.35 to 4.56 ± 0.19 AU with Ad-GFP, respectively, P<0.05). In contrast, in cPLA
2
α
+/+
mice transduction of SFO with Ad-cPLA
2
α shRNA but not its control Ad-shRNA inhibited cPLA
2
expression and its activity, and prevented Ang II to increase SBP (124 ± 4.03 mmHg Ad-cPLA
2
α shRNA vs. 170 ± 5.32 mmHg Ad-control shRNA, P<0.05). These observations and our finding that the inhibitor of AA metabolism, 5, 8, 11, 14-eicosatetraynoic acid, prevents Ang II-induced hypertension suggest that AA released by cPLA
2
α via one or more of its metabolites increases ER and oxidative stress in SFO that promotes development of hypertension.
Abstract 181: Brain Angiotensin II Elevates Bone Marrow Sympathetic Drive
Authors: Zubcevic Jasenka , Santisteban Monica M , Raizada Mohan K , Baekey David M
Published: March 2022

Introduction:
Bone marrow (BM)-derived endothelial progenitor cells (EPCs) contribute to the repair of vasculature, whereas the inflammatory cells (ICs) contribute to the vascular damage. Recently, dysfunctional brain-BM communication has been associated with an impaired BM activity, reflecting a decrease in EPCs and increase in ICs. We hypothesized that an overactive brain RAS leads to elevated sympathetic drive to the BM, which precedes the increase in blood pressure (BP), initiates the EPC/IC imbalance, and contributes to the development of vascular pathophysiology.

Methods:
Sprague-Dawley (SD) rats were infused with 15ng/kg/min Ang II ICV for 7 days. Following this, indirect BP measurements were taken, and the
in situ
decerebrated artificially-perfused preparation (DAPR) was used to compare thoracic (tSNA) and femoral BM sympathetic nerve activity (fSNA) between control and Ang II rats. In order to characterize tSNA and fSNA, we monitored the effects of elevated CO
2
(9%) on the phrenic nerve activity (PNA), tSNA and fSNA. PNA-triggered averaging of integrated tSNA and fSNA signals was performed across 100 phrenic cycles, allowing for quantification of averaged tSNA and fSNA during discrete phases of the respiratory cycle: inspiration (I), post-inspiration (P-I), mid-expiration (M-E) and late expiration (L-E). Thus, the peak levels of tSNA and fSNA during each respiratory phase could be compared across preparations.

Results:
We observed no differences in the BPs of control (95±5 mm Hg) and Ang II rats (96±2 mm Hg). Electrophysiology revealed a characteristic PNA pattern, and peak activity of tSNA and fSNA during the P-I phase, typical of the respiratory-sympathetic coupling. Exposure to 9% CO
2
elevated both the tSNA and fSNA in the control and Ang II rats. However, a 75% increase in the tSNA peak firing, and a 20% increase in the fSNA peak firing were observed in the Ang II rats when compared to the control.

Conclusion:
These observations demonstrate, for the first time, that elevated brain Ang II, at sub-pressor conditions, results in an increased sympathetic drive to the BM. This may initiate early impaired BM activity, reflecting in an imbalance in BM EPCs and ICs, which may contribute to the development of hypertension-related pathophysiology.
Abstract 187: The Absence of Renal ACE Blunts the Renal Response and the Hypertension Induced by Nitric Oxide Synthesis Inhibition
Authors: Giani Jorge F , Janjoulia Tea , Kamat Nikhil , Peti-Peterdi Janos , Toblli Jorge E , Bernstein Kenneth E , McDonough Alicia A , Gonzalez-Villalobos Romer A
Published: March 2022

We previously showed that the responses to angiotensin (Ang) II infusion observed in wild type (WT) mice were effectively prevented in mice lacking renal ACE (ACE 3/3 and ACE 10/10 mice) including: hypertension, renal Ang II accumulation, sodium and water retention, and activation of ion transporters in the loop of Henle (NKCC2) and distal nephron (NCC, ENaC, and pendrin). The aim of this study was to test if the absence of renal ACE also protects against hypertension induced by nitric oxide (NO) synthesis inhibition with L-NAME, a low-plasma Ang II hypertension model associated with renal renin-angiotensin system (RAS) activation. In response to L-NAME (0.5 mg/mL in drinking water, 4 wk; n=12-17), systolic blood pressure (SBP) of WT rose from 110±2 to 135±3 mmHg (p<0.01) while SBP in mice lacking renal ACE did not significantly increase: in ACE 10/10, SBP went from 109±3 to 113±2 mmHg (NS), in ACE 3/3 mice from 103±5 to 110±5 mmHg (NS). ACE 10/10 mice exhibited an enhanced natriuretic/diuretic response vs. WT mice: UNaV during the first 24 h of L-NAME was 188±14 μmol in WT and 314±17 μmol in ACE 10/10 (p<0.01). Ang II content [by immunohistochemistry (IHC)] increased from 8±2 to 28±4 % of positive staining/area (p<0.001) in L-NAME-treated WT mice but remained unchanged in ACE 10/10 mice (from 3±1 to 5±1 % of positive staining/area, NS). Consistent with the dissimilar Ang II content, L-NAME increased renal AGT levels by 2.3±0.3 (p<0.01) in WT but not in the ACE 10/10 mice, 0.8±0.1 fold (NS) vs. non-treated animals. The enhanced natriuresis of the L-NAME-treated ACE 10/10 mice was associated with lower NHE3 expression (0.5±0.1 AU) and lower phosphorylation (-P) of NKCC-P (0.48±0.05 AU) and NCC-P (0.5±0.1 AU) vs. equally treated WT (WT defined as 1, p<0.01). In addition, L-NAME-treated WT mice had higher renal macrophage infiltration (82±8 F4/80+ cells/field, by IHC), higher TNF-α content (24±3 pg/mg, by ELISA) and IL-6 (36±2 pg/mg, by ELISA) vs. L-NAME-treated ACE 10/10 (51±3 F4/80+ cells/field, 14±1 pg/mg and 21±1 pg/mg respectively, p<0.01). In conclusion, our results demonstrate that renal ACE plays a fundamental role driving renal responses, hypertension and inflammation induced by NO synthesis inhibition.
Abstract 190: Angiotensin II Type 1A Receptor Expression by Catecholaminergic C1-neurons in the RVLM is Required for Full Development of Angiotensin Dependent Hypertension
Authors: Jancovski Nikola , Bassi Jaspreet K , Carter David , Allen Andrew M
Published: March 2022

Objectives:
Angiotensin II (Ang II) has a well established role in the development of hypertension via activation of the Ang II type 1A receptor (AT1AR). Whilst renal expression of this receptor is important for the hypertension, other sites appear to be involved. We tested the hypothesis that AT1ARs on catecholaminergic RVLM (C1) neurons are involved in Ang II-induced hypertension.

Methods:
Conditional deletion of AT1AR from C1 neurons was achieved by bilateral microinjections of a lentivirus expressing Cre-recombinase (Lv-PRSx8-Cre) under the control of a phox2 binding site promoter in the RVLM of AT1AR floxed mice. Control mice were injected with the same virus with a GFP transgene (Lv-PRSx8-GFP). Ang II (500ng/kg/minute) was infused subcutaneously via an osmotic minipump for 3 weeks. A noninvasive tail cuff system was used to record BP and heart rate (HR). Immunohistochemical localization of TH, GFP or the macrophage marker CD68 was performed using standard methods in sections from lentiviral microinjected mice.

Results:
Baseline systolic BP was not different between the groups (115±2 mmHg vs. 117±3 mmHg). However, infusion of Ang II induced a gradual pressor response that was greater in the Lv-PRSx8-GFP compared to the Lv-PRSx8-Cre injected mice (146±2 mmHg vs. 137±3 mmHg at day 11). The initial BP increase in the C1-selective AT1AR knockout mice was similar to the GFP mice, but a diversion in the BP response was observed after day 7. Post mortem analysis demonstrated that the lentiviral injections were within the region of the C1 neurons of the RVLM.

Conclusions:
These data demonstrate that AT1AR expression by catecholaminergic C1 neurons in the RVLM plays a role in the development of angiotensin-dependent hypertension.