bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 305: Glycated Hemoglobin Levels Predict Arterial Stiffness nad Endothelial Dysfunction in Resistant Hypertensive Diabetic Subjects
Authors: Moreno Beatriz M , Modolo Rodrigo , Faria Ana Paula , Barbaro Natalia , Sabbatini Andréa , Pansani Isabella , Lima Gabriel , Fontana Vanessa , Melo Silvia Elaine , Moreno Heitor M
Published: July 2021

Introduction:
Endothelial function, intima-media thickness (IMT) and vascular stiffness are variables closely associated in normotensive subjects as well as in hypertensive and diabetic (DM) patients; however this correlation has not been tested in resistant hypertensive (RHTN) individuals. It is known that DM is a very common finding in RHTN, but it is controversial whether this condition causes some incremental impairment in vascular dysfunction in these patients. Also, it is controversial if glycated haemoglobin plasma levels predict arterial abnormalities in RHTN individuals.

Methods:
Two hundred and six RHTN patients were divided in two groups: RHTN+DM (HBglic=7.3%, age= 58.7y, BMI= 30.8, n= 134) and RHTN-nonDM (5.5%, age= 58.3y, BMI= 30.5, n=72). Blood pressure (ABPM and office) was similar between the 2 groups (RHTN+DM= 150/87/63 and RHTN-nonDM= 151/89/62 mmHg; p> 0.05). Arterial rigidity (PWV, m/s, Sphygmocor system), endothelial function (FMD,%) and carotid IMT (mm) were assessed and parametric tests (t Student, Pearson correlation and linear regression) used analyse the data. Results (mean±SD): RHTN-DM group had higher values of PWV (12.1±1.6 vs. 10.7±1.7 m/s; p< 0.001) and lower measurements of FMD (7.3±1.8 vs. 8.2±1.9%; p<0.001); however, IMT values were found similar in the 2 groups (1.02±0.2 vs. 1.01±0.2 mm; p= 0.77). Hbglyc levels correlated with PWV (R=0.31; p<0.001) and FMD (R=-0,52; p<0,0001) only in the RHTN-DM group (RHTN-nonDM: R=0.01, p= 0.93, and R=-0.03, p=0.79, respectively). Linear regression analysis showed statistical significance between HbGlyc and PWV and e FMD only in RHTN-DM patients (p<0.05).

Conclusion:
DM worsened endothelial dysfunction and vascular stiffness, but not IMT, in RHTN subjects. Glycated haemoglobin is an important predictor of arterial rigidity and endothelial function in diabetic RHTN subjects.
Abstract 315: Correlation Between Endothelial Dysfunction and Left Atrial Diameter in Hypertensive Patients With Persistent Atrial Fibrillation
Authors: Mohammadi Leila , Podzolkov Valery , Tarzimanova Aida , Pisarev Mikhail , Loriya Irakli
Published: July 2021

Objective:
To estimate the relationship between endothelial function and left atrial diameter in hypertensive patients with persistent atrial fibrillation (AF) in sinus rhythm maintenance.

Methods:
The study included 50 hypertensive patients with persistent AF with mean age of 60.9±11.2 years, of them 19 women (38%) and 31 men (62%). Endothelial function in all the patients was evaluated by ultrasound assessment of endothelial-dependent flow-mediated vasodilation (FMD) of the brachial artery in response to reactive hyperemia measured in the early morning hours. Myocardial structure and function was assessed using echocardiography.

Results:
Reduced %FMD change (< 10%) was found in 47 (94%) hypertensive patients with persistent AF, implying impaired endothelial function. The average increase in brachial artery diameter 60 seconds after decompression was 5.8 ± 0.9% in this group. All patients had normal left ventricular ejection fraction, end diastolic and systolic volume. We registered enlarged left atrial diameter (> 44 mm) in 45 (90%) patients. There was a strong negative direct correlation between left atrial diameter and endothelial-dependent vasodilation of brachial artery in the patients with persistent AF (r= -0.89, P<0.05).

Conclusion:
A strong negative correlation between left atrial diameter and endothelial-dependent FMD was found in hypertensive patients with persistent AF.
Abstract 318: The Role of Adventitial Resident Sca-1+ Progenitor Cells in Angiotensin II-induced Aortic Stiffening
Authors: Wu Jing , Hoglund Virginia , Dong Xiurong , Chen Wei , Majesky Mark W , Harrison David G
Published: July 2021

Recent studies have shown that the adventitia contains arterial progenitor cells expressing the stem cell antigen-1 marker (Sca-1). These Sca-1
+
cells function as stem/progenitor cells that have been reported to transform into smooth muscle cells and promote neo-intimal formation. We have previously found a striking deposition of adventitial collagen in the setting of experimental hypertension in mice. This fibrotic layer of collagen contributes to aortic stiffening and potentially loss of the windkessel effect, promoting systolic hypertension. Because collagen deposition occurs at the site of Sca1
+
cells, we therefore hypothesized that Sca-1
+
progenitor cells might serve as a source of adventitial collagen. Using confocal microscopy, we first found a dramatic increase of Sca-1
+
cells in angiotensin II-treated vessels in the advential and peri-adventitial region, with no increase in CD68
+
cells. These Sca-1
+
cells represented approximately one fourth of total adventitial cells. Flow cytometry indicated that Sca-1
+
CD31
-
cells were tripled in the aortas of angiotensin II-treated mice (5.6±1.6 ×10
3
vs. 15.9±2.4 ×10
3
cells/per aorta sham vs. angiotensin II, p<0.05). We then isolated aortic Sca-1
+
cells in sham and angiotensin II-treated mice using magnetic-activated cell sorting (MACS) and found collagen 1a1 gene was upregulated more than 7 fold in these cells (0.94±0.17 vs. 7.27±1.22, sham vs. angiotensin II, p<0.01). In addition, we did not see any obvious microvessel staining for Sca-1 in the adventitia, indicating these cells did not arise from the vasa vasorum. In summary, resident Sca-1
+
progenitor cells likely contribute to adventitial collagen deposition and promote angiotensin II-induced aortic stiffening.
Abstract 351: Mineralocorticoid Receptor Antagonism During the Development of Hypertension Improves Cerebral Artery Endothelium Dependent Dilation Even After Treatment Withdrawal
Authors: McClain Jonathon L , Dorrance Anne M
Published: July 2021

Hypertension causes cerebral artery remodeling and increases the risk of stroke. Renin angiotensin system blockade during the development of hypertension has therapeutic effects even after treatment withdrawal. Mineralocorticoid receptor (MR) activation has been implicated in artery remodeling and impaired endothelial function. The possibility that there is a critical therapeutic window for MR antagonism has not been investigated. We hypothesized that temporary MR antagonism while hypertension develops would improve endothelium dependent dilation even after treatment withdrawal. Six-week-old male stroke prone spontaneously hypertensive rats (SHRSP) were treated with spironolactone (Spir; 25mg/kg/day, n=8) from 6-12 weeks then aged to 18 weeks. Age-matched untreated SHRSP were controls (n=8). The middle cerebral artery (MCA) was removed and mounted on a pressure myograph, endothelium dependent dilation was assessed by intralumenal perfusion of 2-methylthioadenosine 5′-triphosphate (2-MeS-ATP), or uridine 5′-triphosphate (UTP). Spir had no effect on blood pressure. The MCA diameter after the development of tone was not different between the groups (197.7 ± 8.7 vs. 199.1 ± 4.1 μm, Spir vs. control). Spir treatment increased nitric oxide (NO) mediated MCA dilation in response to 2-MeS-ATP (% change from baseline; 50.9 ± 5.0 vs. 28.0 ± 4.3, Spir vs. control, p<0.05 ANOVA). Spir treatment also increased UTP mediated dilation (% change from baseline; 48.4 ± 6.0 vs. 37.4 ± 6.7, Spir vs. control, p<0.05 ANOVA), and increased the MCAs sensitivity to UTP as evidenced by a reduction in the Log EC50 for UTP (-9.2 ±0.1 vs. -8.7±0.2 Spir vs. control, p<0.05 t-test). There was no difference in the response to sodium nitroprusside between the two groups (% change from baseline; 42.5 ± 7.2 vs. 47.0 ± 7.6, Spir vs. control). These results suggest that MR antagonism improves both NO and endothelium derived relaxing factor mediated dilation in MCAs when the antagonist is administered while hypertension develops. Intriguingly, the improved endothelial function persists even after several weeks of treatment withdrawal suggesting there may be a critical time window during which endothelial function can be permanently improved in cerebral arteries from SHRSP.
Abstract 352: A Common Hypofunctional Genetic Variant of GPER: Increased Blood Pressure in Female Carriers and Increased Expression in Female Hypertensive Patients
Authors: Feldman Ross D , Gros Robert , Hegele Robert A , Ding Qingming , Hussain Yasin , Ban Matthew R , McIntyre Adam D
Published: July 2021

Activation of the aldosterone/estrogen GPCR, GPER, has been linked to vasodepressor effects. Further, genetic deletion of GPER in one mouse model has been linked to increased blood pressure in female but not male mice. However, the significance of GPER regulation for chronic blood pressure control in humans is unknown. To examine this question we determined the functional significance of expression of a common missense single nucleotide variant of GPER, P16L, and the impact of its expression on blood pressure and in the development of hypertension.

Expression of the GPER P16L variant in rat aortic vascular smooth muscle cells vs. expression of wild type (WT) GPER, was associated with a significant decrease in G1 (1μM, a GPER agonist)-mediated ERK activation and G1-mediated inhibition of apoptosis.

In normotensive subjects, expression of this hypofunctional GPER variant (allele frequency=22%) paralleled an increase in mean arterial blood pressure in females [P16/P16: 80±1 mmHg (n=236) vs P16L carriers: 82±1 mmHg (n=156), p<0.05] but not in males.

To validate the importance of expression of the GPER P16L variant on the development of hypertension, we compared the allele frequency in normotensive vs. hypertensive subjects, the latter recruited from patients referred to a tertiary care level hypertension clinic (n=151). In this hypertensive patient population, the P16L allele frequency was increased in female patients with hypertension (1.4 fold, p<0.05 vs. allele frequency in normotensives) but was not increased in hypertensive males.

In summary, we have determined that the common genetic variant, P16L GPER, is hypofunctional and that expression of this missense single nucleotide polymorphism is associated with increased blood pressure in normotensive subjects and with an increased frequency in hypertensive female but not male patients.

Cumulatively, these data suggest that in females, impaired GPER function is associated with increased blood pressure and risk of hypertension.
Abstract 37: Endoplasmic Reticulum Stress in the Brain Contributes to the Pathogenesis of Non-alcoholic Fatty Liver Disease
Authors: Young Colin N , Dong Frederick N , Horwath Julie A , Mark Allyn L , Davisson Robin L
Published: July 2021

Non-alcoholic fatty liver disease (NAFLD) is a major risk factor for the development of cardiovascular diseases (CVD), including hypertension. While most studies have focused on peripheral mechanisms mediating hepatic dysfunction, a role for the central nervous system in the pathogenesis of NAFLD is less appreciated. Here we tested the
hypothesis
that endoplasmic reticulum (ER) stress in the brain contributes to the development of NAFLD.
First
, adult male C57Bl/6 mice were instrumented with an intracerebroventricular (ICV) cannula for administration of the ER stress inducer thapsigargin (TG; 1 μg/day; 3 days; n=5), or vehicle control (n=4), and allowed 1 week recovery. Short-term induction of ER stress in the brain, using TG, did not alter body weight (26±1 vs. 27±1 g; vehicle vs. TG; p<0.05), food intake or adiposity, but caused a ~20% increase in liver weight (1.04±0.5 vs. 1.25±0.07 g; vehicle vs. TG; p<0.05). ICV TG also elicited an increase in liver lipid droplet accumulation (0.074±0.002 vs. 0.665±0.060 droplets/cm
2
; vehicle vs. TG; p<0.05) and up-regulated hepatic gluconeogenic and lipogenic markers (e.g.
Pepck
mRNA 1.56±0.13 fold vehicle; p<0.05).
Second
, male C57Bl/6 mice either remained on normal chow (n=6) or were fed a high fat diet (HFD; n=8) for a period of 20 weeks, a condition that we and others have shown results in ER stress in the brain. Mice were then implanted with an ICV cannula for administration of the chemical ER chaperone TUDCA (5 μg/day), or vehicle control, and allowed 1 week of recovery. ICV TUDCA administration over 5 days rescued HFD-induced hepatomegaly (1.77±0.18 vs. 1.19±0.07 g; HFD vehicle vs. HFD TUDCA; p<0.05) and reduced obesity-induced liver triglyceride accumulation (365±44 vs. 127±36 mM; HFD vehicle vs. HFD TUDCA; p<0.05), such that HFD ICV TUDCA treated mice were not different from controls. These data demonstrate that induction of ER stress in the brain causes hepatic lipid accumulation, independent of changes in body weight, food intake and adiposity. Furthermore, inhibition of chronic brain ER stress reduces HFD-induced hepatomegaly and hepatic steatosis. Collectively these findings illustrate a novel role for brain ER stress as a contributor to a major risk factor for CVD, NAFLD.

HL63887, HL84207, AHA13POST14410020
Abstract 379: Circulating T Regulatory Lymphocytes and Microvascular Structural Alterations in Hypertensive Patients and Normotensive Subjects
Authors: De Ciuceis Carolina , Rossini Claudia , Airò Paolo , Scarsi Mirko , Tincani Angela , Solaini Leonardo , Agabiti Rosei Claudia , La Boria Elisa , Sarkar Annamaria , Porteri Enzo , Gavazzi Alice , Petroboni Beatrice , Rizzoni Damiano , Agabiti Rosei Enrico
Published: July 2021

Background and Methods.
Different components of the immune system, including innate immunity and adaptive immunity (T effector lymphocytes and T regulatory lymphocytes: Tregs) may be involved in the development of hypertension. In addition, it was recently demonstrated that Tregs may prevent angiotensin II-induced vascular injury/inflammation, while Th1, Th2 and Th17 may play a role in the progression of vascular remodeling. However, no data are available in human beings about relationships between T-lymphocyte subtypes and microvascular structure.

In the present, preliminary study, we enrolled 7 normotensive subjects and 3 hypertensive patients undergoing an election surgical intervention. No sign of local or systemic inflammation was present in any subjects or patients. All patients underwent a biopsy of subcutaneous fat during surgery. Subcutaneous small resistance arteries were dissected and mounted on a wire myograph, morphological parameter were measured, in particular media to lumen ratio (M/L) was calculated. A peripheral blood sample was obtained before surgery for assessment of T lymphocytes subpopulations by flow cytometry.

Results are summarized in the Table. RTE: recent thymus emigrant; naïve: no contact with antigens, TDEM: highly antigen-experienced cells that assume pro-apoptotic properties. Additional significant positive correlations were observed between M/L and Th17 effector lymphocytes: r=0.67, p<0.05).

Conclusion
Our data suggest that some lymphocytes subpopulations may be related to microvascular remodeling, and open the possibility to regress small artery remodeling in human by specific drug modulation of lymphocyte subtypes.
Abstract 386: Body Mass Index Exacerbates the Hypertension Mediated Increase in Endothelial Cell Sloughing and Suppression of Antioxidant Heme Oxygenase-1
Authors: Stone Ryan , Chaffin David , Jude David , Khitan Zeid , Kim Dong Hyun , Khawaja Imran T , Abraham Nader G , Shapiro Joseph
Published: July 2021

Introduction:
Endothelial Progenitor cells (EPCs) are bone marrow derived cells that migrate and differentiate into mature endothelial cells and play a significant role in the re-endothelialization and neovascularization of injured endothelium and restoration of vascular function. We examined whether obesity and hypertension exacerbates the levels of biomarkers including circulating endothelial cells (CEC), serum inflammatory cytokines, and the levels of heme oxygenase -1 (HO-1) in EPC.

Methods:
Peripheral blood from 10 normal, 15 obese, 12 hypertensive, 20 obese-hypertensive and 15 diabetic patients was analyzed for inflammatory cytokines, CEC number, adiponectin and HO-1 levels.

Results:
The levels of inflammatory cytokines increased with BMI and directly correlated with increasing obesity. Similarly, hypertensive patients have elevated CEC which are further increased in obese hypertensive patients (p<.05). HO-1 was reduced (p<.05) in both hypertensive and obese patients when compared to control. Similarly serum adiponectin levels were lower in hypertensive obese patients when compared to controls (p<.01). Inflammatory cytokines IL-1, IL-6, MCP-1 and TNFα were elevated in obese hypertensive patients compared to non-obese hypertensive patients (p<.05).

Conclusion:
We demonstrated in hypertension patients that obesity exacerbates vascular dysfunction and increases circulating endothelial cells and inflammatory cytokines. A reduction in the levels of HO-1 and adiponectin imply reduced antioxidant levels which are contributing factors towards vascular and adipocyte dysfunction in hypertension patients. Thus upregulation of HO-1 offers a potential therapeutic approach in the treatment of this population.
Abstract 412: Obesity is an Independent Predictor Of Arterial Stiffness
Authors: Thanikachalam Mohan , Bai Shasha , Harivanzan Vijayakumar , Baliga Ragavendra R , Abraham William T , Thanikachalam Sadagopan
Published: July 2021

Background
Arterial stiffness assessed by carotid-femoral pulse wave velocity (PWV) is an independent predictor of cardiovascular morbidity and mortality. We aimed to investigate how various measures of obesity affect arterial stiffness.

Methods
We conducted a population-based cross-sectional survey in 8,042 South Indians above the age of 20 years. Following completion of a detailed medical history questionnaire, all participants underwent haemodynamic screening including brachial and central blood pressure, and PWV measurements using a high-fidelity applanation tonometry. The study included anthropometric measurements and fasting blood for total cholesterol (TC), triglyceride (TG), high density lipoprotein (HDL), low density lipoprotein (LDL) and blood glucose (BG) levels. After the exclusion of people with previous history of diabetes, hypertension and dyslipidemia on drug therapy, 5,841 subjects (mean age 41.6 years; 58% women) constituted the study sample

Results
In an univariate analysis, PWV correlated positively with age, mean blood pressure (MAP), heart rate (HR), body mass index (BMI), waist circumference (WC), waist to hip ratio (WHR), body fat percent (BF%), TC, TG, LDL and BG levels (P <0.001) and negatively with HDL levels (P=0.005). In a multivariate regression analysis, majority of the PWV variability in the model was accounted for by MAP and age, (cumulative adjusted R2 change of 32.79% as compared to the total adjusted R2 change of 35.25%). However, BMI (β= 0.042; adjusted R2 change=2.83%; p<0.001) independently correlated with PWV and its contribution to the PWV variability was far more significant compared to LDL, BG and TG (cumulative adjusted R2 change=1.08%). Multivariate regression analysis using the WC, WHR, or BF% instead of the BMI continued to demonstrate a significant independent effect of obesity parameters on PWV.

Conclusion:
In a large a population-based cross-sectional survey the study demonstrates a positive, independent association between obesity parameters and increased arterial stiffness.
Abstract 420: Knockout Mice for Elastase-2, a Novel Angiotensin II Generating Enzyme, Displayed Reduced Sympathetic Modulation of Arterial Pressure and Heart Rate
Authors: Becari Christiane , Durand Marina T , Dias Daniel P , Lataro Renata M , Oliveira Mauro , Fazan Rubens , Guimarães Alessander O , Pesquero João B , Bader Michael , Salgado Maria Cristina O , Salgado Helio C
Published: July 2021

A functional alternative pathway for angiotensin converting enzyme (ACE) in the generation of angiotensin II was described involving the tissue enzyme elastase-2 (ELA2). This notion was provided by studies from arteries (mesenteric and carotid) and heart of normotensive Wistar rats. The increased mRNA expression of ELA2 associated with chronic ACE inhibition in the carotid artery and heart from spontaneously hypertensive rats (SHR) is remarkable. Quite recently, our group developed the ELA2 knockout (KO) mice. Therefore, the objective of the current study was to examine the cardiovascular profile of ELA2 KO mice. Male ELA2 KO and C57BL/6j wild-type (WT) mice (10-14 weeks; n=6-10) were investigated. Five days after the cannulation of the femoral artery under isoflurane anesthesia, the arterial pressure (AP) and heart rate (HR) were recorded in conscious state. The variability of AP and pulse interval (PI) was examined in the frequency domain using Fast Fourier Transform (FFT) algorithm. AP and PI spectra were integrated in low (LF: 0.25 to 1.0 Hz) and high frequency (HF: 1.0 to 5.0 Hz) bands. The mean AP of WT and KO mice was similar (110 ± 3 vs. 117 ± 5 mmHg in KO). However, decreased HR (512 ± 13 vs. 425 ± 17 bpm) and increased PI (117 ± 5 vs. 142 ± 5 ms) were observed in KO mice. KO mice showed lower LF power (7.2 ± 1.6 vs. 1.3 ± 0.47 mmHg2) in the systolic AP spectrum indicating an attenuation of sympathetic modulation in the AP control. The LF power in the PI spectrum was lower (39 ± 4 vs. 25 ± 3.8 nu) in KO mice. The LF/HF ratio was also reduced in KO mice (0.88 ± 0.16 vs. 0.39 ± 0.07) indicating a shift towards parasympathetic modulation of the HR. In conclusion, KO mice for ELA2 displayed a reduced sympathetic modulation of AP and HR indicating that this enzyme plays a role in the cardiocirculatory control in mice.
Abstract 423: Angiotensin II Type 1 Receptor (AT1R) Activating Autoantibodies Contribute to the Pathophysiology of Primary Hyperaldosteronism
Authors: Kem David C , Li Hongliang , Yu Xichun , Velarde-Miranda Carolina , Gomez-Sanchez Celso
Published: July 2021

Objectives:
Activating autoantibodies (AA) to the AT1R second extracellular loop (ECL2) are present in patients with primary aldosteronism (PA). We investigated whether AA from PA and from AT1R-ECL2 immunized rabbits activate AT1R and thereby contribute to hypertension by a direct contractile effect on the vasculature and stimulate adrenal aldosterone production.

Methods:
We studied 5 normal controls (NC) and 15 subjects with biochemically confirmed PA [4 APA, 4 IAH non- and 7 indeterminate (IPA)]. AT1R-AA activity in serum or IgG was analyzed in AT1R transfected CHO cells. Contractile effects were assayed in isolated perfused rat cremaster arteries. We determined the effects of an ARB and the L-aa AT1R-ECL2 target epitope on
in vitro
AT1R cremaster artery responsiveness to patient sera and to MAP-L-aa (AFHYESQ) peptide immunized rabbit serum. We examined the effect of IgG from 7 PA subjects on aldosterone production in HAC15 cells
in vitro
w/wo 1.0 and 10 nM Ang II; and w/wo ARB.

Results:
Serum from PA significantly (p<0.05) increased Ang II-equivalent activity in AT1R-CHO cells in IAH 199± x pM, n=4; APA 177±y pM, n=3; IPA 187±z pM, n=7; vs NC 83±a pM, n=5 and was blocked by 10 μM losartan. IgG from PA decreased perfused rat arteriole diameter in IAH by 22±8(SD)% of a 100% (normalized) baseline, n=4; APA 14±0.8%, n=3; IPA 21±6%, n=7; and NC 7±3.5%, n=5 and was blocked by 10 μM losartan. IgG from 7 PA subjects increased HAC15 aldosterone (aldo) 1.8 fold over baseline (p<0.01) and markedly increased 1nM and 10 nM Ang II-induced aldo by 3.5 fold (p<0.01); and was blocked by ARB. BP in hi Na rabbits rose from 80/60 to 140/90 6 weeks after immunization with AT1R MAP-L-aa AFHYESQ peptide. Arteriole contraction rose from 5% (preimmune) to 30% (post-immunization). Preincubation with the L-aa 2
nd
ECL target reduced contractility to 8%; not different from baseline.

Conclusions:
AA from PA and AT1R-immunized rabbits activates AT1R transfected CHO cells, increases
in vitro
arterial contractility and stimulates basal and Ang II induced HAC15 aldosterone secretion. ARBs and decoy peptides were effective in blocking AA effects
in vitro
. These AA have important etiological and therapeutic implications.
Abstract 426: Blood Pressure Lowering Effect of Triamterene
Authors: Tu Wanzhu , Erdel Blake , He Zangdong , Eckert George , Pratt J Howard
Published: July 2021

Triamterene is a potassium-sparing diuretic, often used in combination with thiazide diuretics for treatment of hypertension. By inhibiting the epithelial sodium channel (ENaC) in collecting duct, it reduces potassium secretion, thus reducing the risk of hypokalemia. But it is unclear whether triamterene also has a blood pressure (BP)-lowering effect. We conducted an observational study to examine the BP effect of triamterene. We extracted medical records of 1723 patients diagnosed with hypertension from an urban hospital. There were 1375 patients on hydrochlorothiazide (HCTZ) alone and 348 patients on a combination of HCTZ and triamterene. We compared the recorded BP using regression analysis and the propensity score method. Patient characteristics of the two treatment groups were largely comparable, except for patients on the combination therapy were more likely to be female (83% vs 66%; p<0.001), slightly older (44.7 vs 42.4 years; p=0.0021), and had more recorded chronic kidney disease diagnosis (1.7% vs 0.5%). Direct comparison showed that mean systolic-BP in the patients on triamterene was lower (132.3 vs 136.8 mmHg; p<0.001). Regression analysis showed that systolic BP was 3.06 mmHg (p=0.0005) lower in patients on combination therapy, after adjusting for patient’s demographic and clinical characteristics. Finally, we estimated the propensity of each patient receiving the combination therapy using a logistic regression model and then classified patients into five homogeneous subgroups based on their estimated propensity values. The combined subgroup analysis showed that mean systolic BP in the triamterene group was 4.66 mmHg lower (p=0.0006). All analyses consistently point to a lower BP in patients who received triamterene, as compared to patients who received HCTZ alone. In conclusion, ENaC inhibition with triamterene at doses that are potassium-sparing also lower BP. The use of triamterene in combination with HCTZ may have antihypertensive properties that heretofore were underappreciated.
Abstract 442: Endoplasmic Reticulum (ER) Stress in the Subfornical Organ (SFO) Induces Peripheral Inflammation in Angiotensin II (Ang-II)-dependent Hypertension
Authors: Lob Heinrich E , Song Jiunn , Butler Scott D , Mark Allyn L , Davisson Robin L
Published: July 2021

The SFO is implicated in peripheral T cell activation and the genesis of Ang-II-dependent hypertension. Our recent studies show that ER stress in the SFO is also a key mechanism underlying the development of Ang-II hypertension. Because the ER is closely integrated with initiation of the adaptive immune response, we hypothesized that ER stress in the SFO contributes to peripheral inflammation in Ang-II hypertension. First, 5 days of intracerebroventricular (ICV) infusion of thapsigargin (Tg, 1 ug/day), a chemical ER stress inducer, caused a significant increase in CD3
+
T cells in aortas (Tg: 11.9 ± 3.5 x 10
3
cells/aorta vs. Vehicle: 2.2 ± 0.7 x 10
3
cells/aorta , n = 6, p<0.05) and blood (Tg: 9.9 ± 1.8 x 10
4
cells/ mL vs. Vehicle: 2.9 ± 0.6 x 10
4
cells/ mL, n = 6, p<0.05). Furthermore, quantitative real-time PCR of SFO micropunches showed a 15-fold increase of TNF-α, a pro-inflammatory cytokine, a 3-fold increase of CCL5, a T cell attracting chemokine and a 3-fold increase in CD3, a T cell marker, (n = 4, p<0.05). To test the functional role of ER stress in the SFO in peripheral T cell activation, we targeted an adenovirus encoding GRP78 (AdGRP78), a molecular ER stress inhibitor, to this brain region during chronic systemic Ang-II infusion (600 ng/kg/min, 14 days). Our results demonstrate a significant reduction in T cell accumulation in aortas compared to control virus (AdLacZ) treatment (AdGRP78: 0.5 ± 0.07 x 10
4
cells/aorta vs. AdLacZ: 8.7 ± 2.1 x 10
4
cells/aorta, n = 6, p<0.05). These data show that 1) brain ER stress induces inflammation in the SFO and peripheral vascular T cell activation, and 2) ER stress in the SFO is linked to peripheral vascular T cell activation in Ang-II-dependent hypertension. These results suggest that ER stress and inflammation in the SFO induce peripheral vascular T cell activation and inflammation in Ang-II hypertension.
Abstract 450: Cardiac Electrophysiological Changes Linked to Vitamin D Receptors Deficiency in Obstructive Nephropathy
Authors: Ferder León , Diez Emiliano , Altamirano Liliana , García Isabel , Ponce Zumino Amira , Mazzei Luciana , Manucha Walter
Published: July 2021

Background:
Chronic kidney disease is highly prevalent and is associated with cardiovascular disease. Paricalcitol protects individuals from some of the renal and cardiovascular complications associated with kidney disease. However, its electrophysiological effect during myocardial ischemia-reperfusion is currently unknown.

Aims:
Using an obstructive nephropathy (ON) model, we plan to investigate the potential, structural, and functional changes of the heart that are linked to vitamin D deficiency.

Methods:
The ureters of adult rats (n = 10) were unilaterally obstructed. An inductor of the vitamin D receptor (VDR) was administered for 15 days (30ng/Kg/day, ip). We evaluated histological, molecular, and biochemical parameters, as well, cardiac electrophysiological activity with ischemia-reperfusion protocol.

Results:
we found changes in the action potential duration (APD) at 90% (* P<0.05 vs. C, +P<0.05 vs. O). The analysis revealed arrhythmias, ventricular tachycardia (VT), and ventricular fibrillation (VF). Arrhythmias were quantified in the following ways: 0 − sinus rhythm, 1 – premature ventricular complex, 2 - salvos, 3 - no sustained VT, and 4 – sustained VT or VF (>30 seconds). * P<0.05 vs. C, +P<0.05 vs. O. Of interest was the finding that appears to prolong Pari ischemia DPA in both the controls and the obstructed animals. Also, a significant bradycardia was established in the ischemic phase of the animals obstructed with Pari, which reversed completely during reperfusion. In hearts from ON model animals, we found high AT
1
expression and marked low VDR expression; these changes were reversed by paricalcitol treatment.

Conclusions:
The reduction of VDR expression in ON hearts could be related to increased arrhythmogenesis. The recovery induced by paricalcitol could protect against ventricular fibrillation by the lengthening of the action potential. Further studies will be necessary to elucidate these interesting kidney-heart interactions.
Abstract 466: Protein Phosphatase 2A and c-Myc as Intracellular Messengers in the Natriuretic Renal Dopaminergic System
Authors: Tran Hanh T , Gildea John J , Felder Robin A
Published: July 2021

G protein-coupled receptor kinase 4 (GRK4) is known to negatively regulate the dopamine-1 receptor (D
1
R) in human renal proximal tubule cells (RPTC) leading to reduced sodium excretion. c-Myc is a transcription factor involved in positive regulation of G protein-coupled receptor kinase 4 (GRK4). Protein phosphatase 2A (PP2A) inhibits c-Myc by dephosphorylating a residue that normally stabilizes c-Myc. We have previously shown that stimulation of the natriuretic D
1
R in RPTC led to an increased ratio of PP2A/c-Myc binding. Treatment with PMA (protein kinase C inhibitor) led to a decreased PP2A/c-Myc ratio and a lack of cAMP accumulation after stimulation with fenoldopam (FEN, D
1
R agonist). We hypothesized that PP2A plays a key role in regulating natriuresis and that perturbation of PP2A would directly have effects on protein levels of c-Myc, the ratio of PP2A/c-Myc, and the accumulation of cAMP. We used normal RPTCs (nRPTC) and RPTCs that have an uncoupled D
1
R that no longer stimulates adenylyl cyclase (uRPTC). Inhibition of PP2A in uRPTCs with okadaic acid (OA, 100nM, 3 hr) caused an increase in c-Myc protein levels (97.8% ± 18.9 SEM; n=6; p<0.05 (1.44 / 0.73 RFU)), a decrease in the PP2A/c-Myc ratio (-81.8% ± 1.5 SEM; n=6; p<0.05 (1.42 /7.82 RFU)), and a lack of cAMP accumulation upon treatment with
SKF38393
(a D
1
R agonist similar to FEN). Activation of PP2A with FTY720 (PP2A activator, 10μM, 3hr) caused a decrease in c-Myc protein levels (- 85.4% ± 2.3 SEM; n=6; p<0.005 (0.11/ 0.73 RFU)), an increase in the PP2A/c-Myc binding ratio by 345.3% ± 90.3 SEM; n=6; p<0.01 (34.82/ 7.82 RFU), and an increase in cAMP accumulation upon stimulation with
SKF38393
(94.0% ± 12.4 SEM; n=3; p<0.05 (9.04/4.66 pmole cAMP/mg protein) compared to VEH. In summary, the D
1
R coupling defect found in uRPTCs was restored through activation of PP2A and inhibition of c-Myc. We conclude that PP2A interacts with c-Myc to regulate the natriuretic effect of the D
1
R providing additional insight into the intracellular regulatory events surrounding sodium excretion.
Abstract 467: Hypertension and Cancer: Are They Related?
Authors: Tran Hanh T , Gildea John J , Felder Robin A
Published: July 2021

There are literature references supporting a link between hypertension and cancer. However, a mechanism for this association has not been defined. Key players in blood pressure regulation include the dopamine-1 receptor (D
1
R), G protein-coupled kinase type 4 (GRK4) and c-Myc, all found in renal proximal tubule cells (RPTC). c-Myc also regulates GRK4 in the breast cancer cell line MCF7. We hypothesized that the D
1
R would act as a tumor suppressor and both GRK4 and c-Myc as oncogenes in MCF7 cells. GRK4 is positively regulated transcriptionally by c-Myc, and GRK4 is negatively regulated by Caveolin-1 (CAV1) in RPTCs, so we tested if the same relationship occurs in this breast cancer model.
SKF38393
(D
1
R agonist, 10μM, 18hr) reduced wild type MCF7 (WT-MCF7) cell motility (an index of aggressive growth) by 16.0% ± 3.2 SEM (n=9; p<0.005; 115393/137330 RFU), while the D
1
R antagonist LE300 (10μM, 18hr) increased cell motility 23.0% ± 7.0 SEM (n=9; p<0.05; 168955/137330 RFU). CAV1, a tumor suppressor and GRK4 kinase inhibitor, is missing in MCF7, so we transfected CAV1 into MCF7 cells (CAV-MCF7) and inhibited cell motility even further following
SKF38393
stimulation (29.8% ± 2.8 SEM; n=11; p<0.005 vs.WT-MCF7; 105801/150766 RFU). CAV1 binding to GRK4 was verified by co-immunoprecipitation. CAV-MCF7 also showed higher levels of basal cell surface D
1
R (103.3% ± 35.9 SEM; n=10; p<0.01 vs WT-MCF7; 808/397 RFU) and D
1
R membrane recruitment post-fenoldopam stimulation (FEN, D
1
R agonist, 10μM, 30min) (increase of 65.5% ± 6.18 SEM; n=4; p<0.05 vs. WT-MCF7; 1.65/1.00 RFU). We verified that CAV-MCF7 showed decreased soft agar colony growth and decreased rates of cell proliferation. Because c-Myc increases GRK4 expression, cell proliferation after c-Myc knock down (KD-MCF7) was tested. KD-MCF7 showed decreased cell proliferation at 48 hr by 37.7% ± 7.6 SEM (n=3; p<0.05 vs WT-MCF7; 2752/4416 cells), while both knockdown of c-Myc and re-expression of GRK4 restored proliferation by 23.1% ± 13.4 SEM (n=10; p<0.05 vs KDMCF; 1346/1093 cells) at 96 hr. We therefore conclude that c-Myc activation of GRK4 inactivates the dopaminergic pathway in both the kidney and breast cancer progression which may be a common link between hypertension and breast cancer.
Abstract 470: Development of Control Cells in a Cell-Based Assay for Salt Sensitivity
Authors: Gildea John , Lahiff Dylan , Opper Phuong , Felder Robin
Published: July 2021

Salt sensitivity of blood pressure (BP) affects 25% of the world’s population and has a cardiovascular risk that is similar to hypertension, but can be present in normotensive individuals. Salt sensitivity can be detected with a two week controlled diet, which is difficult to administer in the clinical setting. Our previous method of determining an individual’s salt sensitivity status through the use of confocal microscopy is challenging as a clinical assay due to its complexity. We therefore developed a rapid method of diagnosis based on exfoliated renal proximal tubule cells (RPTC) in urine. Our streamlined approach made use of an Accuri™ C6 (BD Biosciences) flow cytometer to measure monensin (MON)-stimulated dopamine-1 receptor (D1R) and angiotensin-2 receptor (AT2R) recruitment to the plasma membrane. In order to control for method-induced variability and biological variation, we developed external controls. Two different immortalized cell lines, i22 (D1R coupled) and i19 (D1R uncoupled) were chosen for their consistent level of response to stimulation by MON, a sodium ionophore. These cell lines were each labeled with D1R or AT2R antibodies directly conjugated to R-Phycoerythrin (RPE) (Ex: 535nm, Em: 575nm) to obtain a basal level of surface receptor. Afterwards, the cells were stimulated with MON (1μM) to elicit a Na+ -induced receptor recruitment response. Finally, the cells were stained with directly labeled D1R or AT2R antibodies conjugated to Allophycocyanin (APC) (Ex: 650 nm, Em: 660 nm), after which they were read on the Accuri. Normally coupled i22 cells showed a significantly higher (p<0.005) recruitment ratio (Stimulated RFU (APC) / Basal RFU (RPE)) for D1R of 0.42 (SEM ± 0.012, n=7) than did uncoupled i19 cells, which showed a recruitment ratio of 0.36 (SEM = ± 0.006, n=7). Normally coupled i22 cells showed a significantly higher (p<0.05) recruitment ratio for AT2R of 0.45 (SEM ± 0.018, n=6) than did uncoupled i19 cells, which showed a recruitment ratio of 0.39 (SEM = ± 0.013, n=6). This controlled cell-based assay will facilitate testing in large cohorts to validate its use as a means to determine each individual’s salt sensitivity index.
Abstract 493: Renal Injury Induced by Nitric Oxide Depletion is Prevented by Concomitant Inhibition of Hydrogen Sulfide and/or Carbon Monoxide Production
Authors: Wesseling Sebastiaan , Fledderus Joost O , Verhaar Marianne C , Joles Jaap A
Published: July 2021

Chronic nitric oxide (NO) depletion induces hypertension and renal damage. Hydrogen sulfide (H
2
S) producing cystathionine-γ-lyase (CSE) and carbon monoxide (CO) producing heme oxygenase-1 (HO-1) appear to be protective in mechanically-induced renal injury (e.g. ischemia reperfusion). However, inhibition of CSE can reduce drug-induced renal injury (e.g. cisplatin). The role of renal H
2
S and HO-1 during chronic NO depletion is unknown. We hypothesized that renal injury secondary to NO depletion via inhibition of NO synthase is diminished by additional H
2
S depletion via inhibition of CSE.

Rats (n=6/group) were treated with inhibitors of NO synthase (L-nitroarginine; LNNA), CSE (DL-propargylglycine; PAG), or HO-1 (Sn(IV) protoporphyrin IX dichloride; SnPP) for 1 or 4 weeks or with combinations (LNNA+PAG; LNNA+SnPP; PAG+SnPP or LNNA+PAG+SnPP) for 4 weeks.

One week LNNA reduced urinary NOx excretion (35±2% vs baseline) and induced hypertension (173±12 vs. 137±3 mmHg; P<0.01) but renal function remained normal. Four weeks of LNNA further reduced NOx (7±1%), worsened hypertension (223±10 mmHg) and caused renal injury; plasma urea (17±4 vs 7±1 mmol/L; P<0.05), proteinuria (144±35 vs 17±2 mg/d; P<0.01). PAG or SnPP had no effect. NOx was reduced by PAG and increased by SnPP. Renal H
2
S production was completely blocked by PAG and enhanced by SnPP at 1 and 4 weeks. Renal HO-1 expression was induced by LNNA at 4 weeks and by PAG and SnPP at 1 and 4 weeks (all P<0.001).

Adding PAG, SnPP, or both, to LNNA did not affect hypertension but preserved renal function. Combining PAG and SnPP had no effect on blood pressure or renal function. Reduction of urine NOx by LNNA was not affected by additional PAG (8±2%) but was ameliorated by adding SnPP (37±4%) or PAG+SnPP (42±9%). Renal H
2
S production was completely inhibited with all PAG-combinations (P<0.01), but was twofold enhanced by LNNA+SnPP (P<0.01). Renal HO-1 expression was increased by all combinations.

NO depletion resulted in hypertension and progressive renal injury that was prevented by concomitant inhibition of CSE and/or HO-1. Depletion of H
2
S and CO in the absence of NO depletion had no effect on blood pressure and renal function. These data suggest that pathways from NO depletion to renal injury run via H
2
S or CO.
Abstract 515: Central Angiotensin (ang) (1-7) Inhibits the Sensitizing Effects of a Low Dose Ang Ii in Hypertension Produced by a Subsequent Slow Pressor Dose of Ang Ii in Male and Female Rats
Authors: XUE BAOJIAN , Guo Fang , Hay Meredith , Johnson Alan K
Published: July 2021

Previous studies using an
Induction-Delay-Expression (I-D-E)
experimental design demonstrated that pre-treatment with ANG II for 1 week produces a sensitized hypertensive response to subsequent ANG II administration in males but not in females. In this sensitization process, several brain renin-angiotensin-aldosterone system components including angiotensin converting enzyme 2 (ACE2) expressions were enhanced. It has been shown that ANG (1-7), formed from ANG II by ACE2, plays an anti-hypertensive role in the central nervous system. The present study tested whether central ANG (1-7) protects against the sensitizing effects of a low dose of ANG II.

Male and female rats were implanted for telemetered blood pressure (BP) recording. During
I
low doses of ANG II alone or with concurrent icv administration of ANG (1-7) or its antagonist A-779 were given for 1 week. After a 1 week rest (
D
), a slow pressor dose of ANG II was given for 2 weeks (
E
).

In males, the low dose of ANG II during
I
resulted in an enhanced pressor response to the subsequent slow pressor dose of ANG II given during E in comparison to those rats receiving vehicle during
I
(Δ42.8±7.2 vs Δ21.2±5.3 mmHg). Central administration of ANG (1-7) during
I
blocked the low dose ANG II-induced sensitization (Δ16.4±4.0 mmHg). In contrast, the low dose of ANG II did not sensitize the hypertensive response in females to the subsequent slow pressor dose of ANG II (Δ13.0±5.4 vs Δ9.9±3.4 mmHg). Central blockade of ANG (1-7) by icv infusion of A-779 during
I
resulted in sensitization by the low dose of ANG II (Δ26.7±2.0 mmHg) in females. The results indicate that ANG (1-7) plays a protective role during the sensitization process, especially in females, and its administration can attenuate the development of ANG II-induced hypertension in both male and female.
Abstract 529: Muscle Sympathetic Nerve Activity is Higher in Winter than Other Seasons
Authors: Cui Jian , Muller Matthew D , Kunselman Allen R , Blaha Cheryl , Sinoway Lawrence I
Published: July 2021

Epidemiological data suggest that blood pressure tends to be higher in winter and lower in summer, particularly in the elderly. Moreover, hospitalization and mortality rates due to cardiovascular disease have higher rates in winter than summer. Whether autonomic adjustment including muscle sympathetic nerve activity (MSNA) varies with season is unclear. To test the hypothesis that resting MSNA varies along the seasons, we retrospectively analyzed the supine baseline (6 min) MSNA and heart rate (from ECG) of 57 healthy subjects (33M, 24F, 29 ± 1 yrs, range 22-64 yrs) from studies in our laboratory (room temperature ~23 °C). Each of these subjects from central Pennsylvania was studied during 2 or more seasons (total 231 visits). A linear-mixed effects model, which is an extension of the analysis of variance model accounting for repeated measurements (i.e. season) per subject, was used to assess the association of season with the cardiovascular outcomes. The Tukey-Kramer procedure was used to account for multiple comparisons testing between the seasons. MSNA burst rate in winter (21.3 ± 1.0 burst/min) was significantly greater than in summer (13.7 ± 1.0 burst/min,
P
< 0.001), spring (17.5 ± 1.6 burst/min,
P
= 0.04) and fall (17.0 ± 1.2 burst/min,
P
< 0.002). There was no significant difference in MSNA in other comparisons (spring vs. summer,
P
= 0.12; spring vs. fall,
P
= 0.99; summer vs. fall,
P
= 0.054). Heart rate (63.6 ± 1.1 vs. 60.8 ± 1.2 beats/min,
P
= 0.048) was significantly greater in winter compared to summer. Blood pressure (automated sphygmomanometry of the brachial artery) was not significantly different between seasons. The results suggest that baseline sympathetic nerve activity varies along the seasons, with peak levels evident in winter. We speculate that the seasonal MSNA variation may contribute to seasonal variations in cardiovascular morbidity and mortality.
Abstract 53: Measurement of Peripheral Blood 18-Oxocortisol as the Diagnostic Method of Primary Aldosteronism and Its Subtypes
Authors: Satoh Fumitoshi , Morimoto Ryo , Kudo Masataka , Iwakura Yoshitsugu , Ono Yoshikiyo , Matsuda Ken , Takase Kei , Gomez-Sanchez Celso E , Rainey William E , Sasano Hironobu , Nakamura Yoshihiro , Ito Sadayoshi
Published: July 2021

Backgrounds:
Primary aldosteronism (PA) is diagnosed and treated by the long steps, such as screening, confirmation testing and subtype diagnosis (computed tomography (CT) scan and adrenal venous sampling (AVS)). AVS has been the only reliable subtype classification method between surgically curable unilateral aldosterone producing adenoma (APA) and bilateral idiopathic hyperaldosteronism (BHA). In spite of increased numbers of specialized centers with superior ability of AVS in the world, unfortunately, this test is costly and requires a dedicated and expert radiologist; therefore it is not generally utilizable in most hospitals. It is understandable that easier diagnostic tools to be substitutes for AVS might be hoped by clinicians.

Objective:
The aim of the study was to determine the role of peripheral plasma levels of 18-oxo-cortisol (p18oxoF) and 18-hydroxycortisol (p18OHF) in differentiate APA from BHA.

Patients:
The study included 265 PA patients (113 patients with CT-positive macro APA, 31 patients with CT-negative micro APA and 121 patients with BHA) and 79 patients with essential hypertension (EH).

Methods:
All of 265 PA patients underwent AVS successfully, and any case with APA was surgically proven and pathologically confirmed including immunohistochemical analysis of steroidogenic enzymes. We measured p18oxoF and p18OHF of all PA patients by high sensitive LC ms/ms.

Results:
APA patients showed significantly higher p18oxoF and p18OHF than those of BHA patients and EH patients. The ROC analysis of p18oxoF in macro APA versus BHA demonstrated clinically useful discrimination with higher sensitivity of 0.83 and higher specificity of 0.99 by cutoff value of 4.7 (ng/dl), compared to the classification by p18OHF. Practically, 86 (76%) of macro APA patients with p18oxoF above 6.1 (ng/dl), which was the maximum level in BHA patients, might have been able to undergo surgery without AVS. Because the maximum p18oxoF in EH patients was 5.6 (ng/dl), the patients with p18oxoF above 6.1 (ng/dl) after screening of PA could also undergo surgery if unilateral adenoma(s) can be found on CT; thus it means omitting confirmation tests.

Conclusions:
Peripheral blood 18oxoF measurement can be a clinically useful method for the diagnosis of PA and its subtypes.