bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 197: Effect of Selective Afferent Renal Denervation by Periaxonal Application of Capsaicin on Salt Sensitivity of Arterial Pressure
Authors: Foss Jason , Engeland William C , Osborn John W
Published: July 2021

Renal nerves contribute to some forms of hypertension, but the differential role of afferent and efferent renal nerves remains unclear. It has been proposed that afferent renal nerves modulate arterial pressure (AP) since rats subjected to dorsal rhizotomy (DRX) at spinal levels T9-L1 exhibit salt-sensitive hypertension. Since DRX is not selective for renal afferents, we developed a novel method for selective ablation of calcitonin gene-related peptide (CGRP) positive sensory fibers in the kidney and tested the hypothesis that, as with DRX, our method of afferent renal denervation (ARDN) causes salt-dependent hypertension in rats. Male Sprague Dawley rats were implanted with radiotelemeters to measure AP and heart rate (HR) and underwent either ARDN (renal-CAP) or sham surgery (SHAM). In renal-CAP rats, the renal nerves were exposed to a 33 mM capsaicin solution for 15 minutes. The rats were housed in metabolic cages, fed a 0.1% NaCl diet and allowed to recover for 10 days. After a 4 day baseline period, the diet was increased to 4% NaCl for 3 weeks then 8% NaCl for 2 weeks. At the end of the protocol the rats were euthanized and immunohistochemistry (IHC) was performed on the kidneys labeling for CGRP, as a marker of afferent renal fibers, and tyrosine hydroxylase, as a marker of efferent renal fibers. Baseline mean AP (mmHg) was slightly higher in renal-CAP (103 ± 2) than SHAM rats (97 ± 3) whereas HR (BPM) was similar (399 ± 11 vs. 395 ± 10). Increasing salt intake caused a similar increase in MAP in both groups, but HR decreased more in SHAM than renal-CAP rats (358 ± 6 vs. 385 ± 3 BPM). Sodium and water intake, excretion and balance were not different between the two groups. IHC confirmed the selective destruction of renal afferent fibers. These data suggest that: 1) renal-CAP treatment is an effective method for ARDN, 2) afferent renal nerves play a minimal role in the regulation of AP or sodium and water balance in normotensive rats, regardless of salt intake and 3) afferent renal nerves appear to mediate sodium dependent decreases in HR. The discrepancy between these results and those of previous studies may be due to the non-selective nature of DRX.
Abstract 207: C-Reactive Protein Signaling via Neurokinin B Receptor Contributes to the Pathophysiology of Preeclampsia
Authors: Parchim Nicholas , Wang Wei , Liu Chen , Siddiqui Athar , Kellems Rodney , Xia Yang
Published: July 2021

Introduction:
C-Reactive Protein (CRP) is an important immunomodulatory molecule. Early studies have indicated that CRP is elevated in preeclamptic patient sera, but its function remains unclear. CRP is known to bind with phosphocholine (PC) of bacteria membrane to kill bacteria by triggering innate immune response. Phosphocholination is a post-translational modification mediated by PC transferase, an enzyme reported expressed only in two tissues, including placenta and testis. Recent studies identified that Neurokinin B (NKB), a known, placenta-enriched pathogenic molecule for preeclampsia (PE), is phosphocholinated. This modification increases its stability, preferentially activates NK3 receptor (NK3R) and promotes PE features. Given CRP can bind to PC on bacterial membranes, the role that phosphocholination plays is a mystery. In light of NKB, being phosphocholinated in the endoplasmic reticulum and signals via the NK3R in the pathogenesis of PE, we feel that elevated CRP may be associated with NKB and contributes to the pathophysiology of PE via NK3R activation.

Results:
ELISA results show that CRP is significantly elevated in PE vs. control sera_65 ug/mL vs. 10 ug/ml; p<0.0001. Western blot analysis reveals that CRP, NKB, and NK3R are significantly increased in PE vs. control placental tissue. Immunohistochemistry studies indicate that all of these three molecules are abundant in syncytiotrophoblast cells. Co-immunoprecipitation demonstrates an interaction between CRP and NKB.
In vitro
, we provide the first evidence that CRP decreased the invasion of trophoblast cells from 0.7 ± 0.06 to 0.06 ± 0.001 invasion index; p<0.005, while treatment with
SB222200
ameliorates shallow invasion from 0.28 ± 0.09 to 0.55 ± 0.07 invasion index; p<0.05. Significantly, infusion of CRP into pregnant mice
induces
hypertension (169.152 ± 14.7 mmHg vs. 141.916 ± 6.93 mmHg; p<0.05) and proteinuria (28.78 ± 13.56 mg albumin/μg Cr vs. 13.87 ± 3.277 mg albumin/μg Cr; p<0.05).

Conclusion:
Our findings demonstrate elevated CRP contributes to PE and NKB/NK3R is a new mechanism underlying CRP-mediated shallow invasion and disease development. These studies suggest novel pathogenic biomarkers and innovative therapies for PE.
Abstract 211: Inhibition of Heme Oxygenase-1 (HO-1) Induces Mild Hypertension in Pregnant Rats
Authors: George Eric M , Spradley Frank , Granger Joey P
Published: July 2021

In the preeclamptic patient, inadequate remodeling of the maternal vasculature exacerbates this effect, causing dramatically increased oxidative stress in the placenta, which has been shown to be an important component of the maternal hypertension. There is also increasing awareness that HO-1 may act as an important regulator of placental function during normal pregnancy and decreases in HO-1 activity have been implicated in the pathogenesis of preeclampsia. While previous work in pregnant mice demonstrated that pharmacological inhibition of HO-1 leads to elevations in blood pressure, the mechanisms involved in the hypertension are unclear. The purpose of this study was to test the hypothesis that HO inhibition in late gestation leads to increases in maternal blood pressure by altering angiogenic balance and increasing placental oxidative stress in pregnant rats. HO activity was inhibited with tin mesoporphyrin (SnMP) was administered on gestational day 14, and blood pressure was measured on gestational day 19 by indwelling carotid catheter before sacrifice. In response to SnMP treatment, maternal MAP was significantly increased (99±1 vs 113±2 mmHg, p<0.05, n=15 per group). Placental sFlt-1 (631±47 vs 648±26 pg/mg, p=0.76) levels in the placenta were not affected by HO inhibition. Additionally, there was no significant difference in free VEGF in the maternal circulation (287±22 vs 329±14 pg/ml, p=0.11). There was, however, a significant increase in placental NADPH oxidase activity in SnMP treated rats (2021±238 vs 3005±301 RLU/min/mg, p<0.05) as determined by NADPH dependent lucigenin luminescence. This is likely due to decreased production of bilirubin, which is known to inhibit NADPH oxidase activity, and suggests an important role for HO-1 as an antioxidant in the developing placenta.
Abstract 227: The Protective Effect of Kidney-Specific ACE Inhibition Against Chronic Angiotensin II Infusions is Associated with Blunted Intrarenal Renin-Angiotensin System Activation
Authors: Giani Jorge F , Djandjoulia Tea , Fetcher Nicholas , Fuchs Sebastien , Seth Dale M , Peti-Peterdi Janos , Navar L. G , McDonough Alicia , Bernstein Kenneth E , Gonzalez-Villalobos Romer A
Published: July 2021

Introduction:
The responses to chronic angiotensin (Ang) II infusions of gene-targeted mice lacking kidney angiotensin-converting enzyme (ACE), in terms of intrarenal Ang II accumulation, hypertension, sodium and water retention are all blunted or absent. The objective of this study was to determine if these reduced responses were associated with changes in the intrarenal renin-angiotensin system (RAS).

METHODS:
Mice lacking intrarenal ACE (ACE10/10) were generated by targeted homologous recombination placing the expression of ACE only in macrophages. As a result, these mice have normal circulating ACE levels, but no kidney ACE. Wild-type (WT) mice of the same background (C57Bl/J) served as controls. Mice were subjected to sham-operation or subcutaneous infusion of Ang II for two weeks (n=6-10, 400 ng/kg/min via osmotic minipump). Mean arterial pressure (MAP) was followed by telemetry. At the end of the experiment, the kidneys were collected for analysis. Ang II content was measured by RIA. Renal abundance of ACE, angiotensinogen (AGT) and Ang II receptor type 1 (AT1R) were determined by Western Blot in total kidney homogenates.

Results:
At baseline, the MAP of WT and ACE 10/10 mice was similar 110 ± 4 mmHg vs. 109 ± 3 mmHg respectively (p>0.05). However, when subjected to chronic Ang II infusions, the hypertensive response was blunted in ACE 10/10 mice (129 ± 6 mmHg) vs. WT (146 ± 5 mmHg; P<0.05). Also, intrarenal Ang II accumulation was lower in ACE10/10 mice (724 ± 81 fmol/g) vs. WT (1130 ± 105 fmol/g, p<0.05). In non-treated mice, intrarenal RAS components analysis revealed that the absence of ACE in ACE10/10 mice was accompanied by a significant reduction in AGT (0.41 ± 0.06) and increased AT1R expression (1.32 ± 0.05) when compared to WT (normalized to 1.00, p<0.05 in both instances). Importantly, after chronic Ang II infusions, AGT, ACE and AT1R expression increased in WT (1.36, 1.26 and 1.17 fold increase respectively compared to non-treated WT, p<0.05) but not in the ACE10/10 mice (1.19, 1.06, 0.89 fold increase respectively compared to non-treated ACE10/10, p>0.05).

Conclusion:
The blunted hypertension and Ang II accumulation of mice devoid of kidney ACE in response to Ang II infusions is associated with a failed induction of renal AGT and the AT1R.
Abstract 235: Role of Angiotensin Converting Enzyme on the Production of Angiotensins From Angiotensin-(1-12) In Normotensive Wistar-kyoto Rats and Spontaneously Hypertensive Rats
Authors: Moniwa Norihito , Ahmad Sarfaraz , VonCannon Jessica L , Simington Stephen W , Varagic Jasmina , Ferrario Carlos M
Published: July 2021

We investigated the metabolic pathways contributing to angiotensin II (Ang II) formation from Ang-(1-12) in WKY and SHR. Intravenous infusion of Ang-(1-12) (2 nmol/kg/min) induced a significant pressor response (+ 48 ± 5 mm Hg). Pretreatment with lisinopril [angiotensin converting enzyme (ACE) inhibitor, 10mg/kg] abolished the pressor response by Ang-(1-12) while chymostatin (chymase inhibitor, 10mg/kg) had no effect on the blood pressure rise by Ang-(1-12). ACE inhibition increased plasma Ang-(1-12) from an average of 6,750 ± 2,871 to 23,345 ± 4,509 fmol/mL in vehicle and lisinopril-treated WKY (P < 0.01), respectively (Figure), whereas in SHR plasma Ang-(1-12) rose to 14,334 ± 5,971 in lisinopril-treated compared to 432 ± 142 fmol/mL in vehicle-treated SHR (P < 0.01). The degradation of Ang-(1-12) into Ang I following lisinopril treatment resulted in plasma Ang I averaging 4,762 ± 746 in WKY versus 2,724 ± 657 fmol/mL in SHR compared to plasma Ang I of 744 ± 149 and 580 ± 81 fmol/mL in vehicle-treated WKY and SHR (all P < 0.01). ACE inhibition suppressed Ang II formation from Ang-(1-12) to almost the detectable level of the assay. In contrast, chymostatin increased plasma Ang-(1-7) (138% of control, P<0.05) while having no effect on Ang-(1-12), Ang I or Ang II following Ang-(1-12) infusion compared to control in WKY but not SHR. The data shows that Ang-(1-12) metabolism or plasma clearance is significantly augmented in SHR compared to WKY and that in both strains ACE acts as the primary source for the direct circulatory conversion of Ang-(1-12) into Ang II. Furthermore, we now show for the first time a role of chymase in acting as an Ang-(1-7) degrading enzyme in WKY.
Abstract 241: Influence of Dietary Salt and Renin-angiotensin System activity on plasma Retinol-binding Protein 4 in Healthy Human Subjects
Authors: Shafiq Qaiser , Williams Jonathan S
Published: July 2021

Introduction:
Retinol-binding protein 4 (RBP-4) is a circulating adipokine associated with insulin resistance, obesity and cardiovascular risk. Previous evidence suggests a negative impact on insulin sensitivity via an interaction with the insulin-stimulated glucose transporter (GLUT-4), specifically in adipocytes. Since angiotensin-2 (ANG-2) impairs GLUT-4 presentation and insulin sensitivity, we hypothesized that renin-angiotensin system (RAS) activity might affect RBP-4 expression as well. Furthermore, both RAS activity and insulin sensitivity are affected by dietary salt, but the relationship between these factors and RBP-4 expression is unknown. We hypothesized that liberal salt diet, via suppression of RAS activity, would be associated with reduced RBP-4 levels compared to salt restriction.

METHODS:
Healthy subjects (7 men, 7 women, mean age 24 yr, BMI 22.6) were studied on low salt (LS 10 mmol Na/day) diet and then liberal salt (HS 200 mmol Na/day) diet for 1 week each. Samples were drawn after overnight rest in the supine position for plasma renin activity (PRA), serum Aldosterone (Aldo) and plasma RBP-4 and again after ANG-2 infusion (3ng/kg/min x 45 mins).

Results:
Salt manipulation predictably modified RAS activity (HS v. LS Aldo, 4.5 ± 3.8 v. 19.5 ± 8.5 ng/dl [p<0.01]; HS v. LS PRA, 0.5 ± 0.4 v. 2.7 ± 1.4 ng/ml/hr [p<0.01]). RBP-4 was significantly lower on a HS compared to LS diet (35.4 ± 6.6 v. 38.6 ± 7.9 mg/L, p= 0.017). No significant change was observed in RBP-4 level after ANG-2 infusion on either diet. Fasting insulin levels trended lower on HS compared to LS (3.9 ± 6.8 v. 4.4 ± 1.2 μIU/ml, p=0.09), but there was no difference in fasting glucose (81.9 ± 6.8 v. 82.1 ± 4.7 mg/dl, p=0.92).

Conclusion:
RBP-4 levels are modified by dietary salt intake. RBP-4 levels were lower under HS conditions (suppressed RAS) as compared to LS conditions. Acute administration of ANG-2 does not increase RBP-4 levels in this healthy population. Insulin response was similar to prior reports suggesting that the connection between RAS activity, dietary salt and insulin sensitivity may include RBP-4. Future work exploring the relationship between RBP-4, GLUT-4 and insulin sensitivity should take into consideration the effect of dietary salt intake.
Abstract 249: High Salt and Aldosterone Increase (pro)renin Receptor Expression Through Enac α Activation in Neuronal Cells
Authors: Peng Hua , Li Wencheng , Feng Yumei
Published: July 2021

Activation of the brain renin-angiotensin-aldosterone system plays an essential role in hyperactivity of the sympathetic nervous system during salt sensitive hypertension. We previously reported an up-regulation of (pro)renin receptor (PRR) expression levels in DOCA-salt hypertensive mice brain. However, the mechanism by which PRR is regulated in DOCA-salt hypertension remains unknown. We hypothesize that aldosterone increases PRR expression by activation of epithelial sodium channel (ENaC). To test this hypothesis, we used neuro-2A cell line from brain hypothalamus which expresses all ENaC α, β, and γ subunits, as well as mineralocorticoid receptor (MR). Cells were incubated in normal salt (NS, 142 mM) or high salt (HS, 160 mM) culture medium for 1, 3, or 5 days, with or without the addition of aldosterone (1μM) for 2 hours. Interestingly, the combination of HS (5 days) with aldosterone significantly increased PRR mRNA levels (fold change) (3.28 ± 0.11) compared to NS (1.00 ± 0.01), HS (1.23 ± 0.01), or aldosterone (1.40 ± 0.01) alone in Neuro-2A cells. The PRR expression levels (1.253 ± 0.006; 1.89 ± 0.002) were significantly attenuated by ENaC inhibition (amiloride, 10μM) or MR inhibition (eplernone, 10μM) respectively (P<0.05), suggesting that ENaC and MR activation mediates the up-regulation of PRR expression in neuronal cells. Furthermore, HS increased ENaC α (2.42 ± 0.01), while decreased ENaC β (0.05 ± 0.01), and ENaC γ (0.03 ± 0.01) mRNA expression levels compared to NS treatment (1.00 ±0.01) in Neuro-2A cells suggesting an increase in synthesis rate of α subunit following HS treatment. In summary, HS and aldosterone increase PRR expression levels via activation of ENaC. ENaC α may be the regulating subunit in the assembly of functional ENaC in neuronal cells. We conclude that regulation of PRR expression by high salt and aldosterone may be the critical step to activate angiotensinergic sympatho-excitatory pathways leading to salt sensitive hypertension.
Abstract 266: Renovascular Remodeling in Hypertensive Dahl-SS Rats: Role of MMP Inhibitor as a Hypertension Ameliorating Agent
Authors: Kundu Sourav , Pushpakumar Sathnur , Metriveli Naira , Tyagi Suresh C , Sen Utpal
Published: July 2021

High salt diet has long been associated with chronic hypertension. The development of renal injury in Dahl salt-sensitive (SS) hypertensive rats is characterized by structural and functional changes involving vascular remodeling. Increased activity of matrix metalloproteinases (MMPs) leading to alteration in the extracellular matrix (ECM) is the main mechanism contributing to increased peripheral vascular resistance. In this study, we hypothesized that inhibition of MMPs will modulate ECM remodeling by decreasing MMP activity and thus reduce mean arterial blood pressure.

METHODS:
We used Dahl-salt sensitive (Dahl-SS) and

Lewis rats fed on high salt diet. The groups were 1) Dahl-SS, 2) Dahl-SS+GM6001 (non-specific MMP inhibitor), 3) Lewis, and 4) Lewis+GM6001. GM6001 was given at 0.5mg/mL by intra-peritoneal injection on alternate days for 3 weeks. Blood pressure, laser doppler flowmetry for renal cortical blood flow and barium angiography for renal vascular density were measured.

Results:
Mean arterial blood pressure was 172.10 ± 0.57 mm Hg in hypertensive Dahl-SS rats compared to 136.12 ± 1.22 mm Hg in Dahl-SS+GM6001 rats. The mean arterial pressures in lewis and lewis+GM6001 groups were 97.08 ± 0.56 and 87.63 ± 2.93 mm Hg respectively. Laser doppler flowmetry showed reduced renal cortical blood flow (1333.33 flux units) in Dahl-SS rats compared to Dahl-SS rats treated with GM6001 (1605 flux units). Lewis rats showed similar renal cortical flow with (1488.33 flux units) or without GM6001 (1425 flux units). Barium angiography demonstrated increased renal vascular density with patent branches in the renal cortex of animals treated with MMP inhibitor, GM6001.

Conclusion:
Our results suggest that in hypertensive Dahl-SS rats, inhibition of MMP attenuates high blood pressure, maintains patency of renal cortical vessels thus improving cortical blood flow.
Abstract 284: A Pilot Study Comparing Two Ambulatory Blood Pressure Monitors Worn at the Same Time
Authors: Kallem Radhakrishna R , Meyers Kevin , Sawinski Deirdre , Townsend Raymond R
Published: July 2021

Introduction Ambulatory blood pressure monitoring (ABPM) has been proposed as the most effective way to characterize a person’s BP profile. However, there are very limited data in the literature comparing two simultaneously worn ABPM devices. Therefore, we compared an eight hour daytime simultaneous ABPM using two monitors (Mobil-O-Graph [I.E.M., Stolberg, Germany] and Spacelabs 90207 [Spacelabs Medical, Issequah, WA]).

Methods
Simultaneous BP and heart rate data were measured on 13 adult volunteers at the University of Pennsylvania using the two monitors over an 8 hour period. Other demographic data were also collected. Standard seated BPs were obtained in triplicate at the beginning and end of the 8 hour monitoring period using an Accutor (Datascope, Mahwah, NJ) device. Three blood pressures were obtained at 1 minute intervals, recorded and averaged for each arm using the Accutor device.

Results
The data show high concordance of measured mean arterial pressures (Mobil-O-Graph 101.4 [SEM-2.0] mmHg, Spacelabs 100.6 [SEM-2.4] mmHg) and heart rates (Mobil-O-Graph measuring 82.4 [ SEM- 4.1] beats/minute, Spacelabs 81.7 [4.0] beats/minute) between the monitors. Spacelabs measured a 10 mmHg higher systolic pressure (p=0.0016) and a non-statistically significant, but numerically higher (2.8 mmHg) diastolic pressure (Figure 1).

Conclusion
The systolic BP difference between the two devices has public health importance. These differences if confirmed in larger cohorts, ABPM manufacturers should consider developing a normative database to help practitioners interpret ABPM data obtained with their device.
Abstract 301: Pleiotropic Effects of Ginkgo Biloba: Implication in Blood Pressure Regulation
Authors: Siegel Günter , Jumar Agnes , de Mey Christian , Ermilov Eugeny
Published: July 2021

Introduction:
In policlinic patients with disorders of lipid metabolism, systolic blood pressure (BP) is correlated to the oxLDL/LDL ratio (r = 0.3879; p < 0.0376). Therefore, we sought to determine whether BP could be lowered in metabolic syndrome (MS) patients by a phytochemical approach. In a 2-month clinical pilot study with
Ginkgo biloba
(EGb 761, 2 × 120 mg/d) known as excellent ROS scavenger on 11 MS patients, a novel biomarker spectrum made point-of-care theranostics feasible.

Methods:
ELISAs, EIAs and biosensor ellipsometry were applied.

Results:
The ratio oxLDL/LDL was reduced by 21.0% (p < 0.002), 8-
iso
-PGF
2α
39.8% (p < 0.0027), MPO 29.6% (p < 0.0137), IL-6 12.9% (p < 0.0407), hs-CRP 39.3% (p < 0.0049), Lp(a) 26.3% (p < 0.001), MMP-9 32.9% (p < 0.042), insulin 9.4% (p < 0.042), HOMA-IR 14.0% (p < 0.0244), nanoplaque formation 14.3% (p < 0.0077), nanoplaque size 23.4% (p < 0.0004), whereas SOD was augmented 17.7% (p < 0.0095), GPx 11.6% (p < 0.001), cAMP 43.5% (p < 0.001), and cGMP 32.9% (p < 0.001). Correlating ΔBP
sys
to ΔoxLDL/LDL resulted in a significant positive linearity allowing for 20 mmHg regulation breadth (Figure). Moreover, BP
dias
was reduced by 5.2 ± 2.3 mmHg (p < 0.0479) from 88.1 ± 2.1 mmHg to 82.9 ± 2.6 mmHg (p < 0.0479). The beneficial effects of ginkgo on oxidative stress parameters and on the changes in cytokine pattern could supply a mechanistic explanation.

Conclusion:
Ginkgo had beneficial effects on a multitude of oxidative stress, inflammatory, diabetic and arteriosclerotic biomarkers. BP
dias
was diminished by 5.8 ± 2.6% and reached reference values on average. Thus, ginkgo may be used as complementary drug in the treatment of borderline hypertension in MS patients.
Abstract 302: Negative Effects of Fludrocortisone Treatment in Adolescents with POTS and Syncope
Authors: Shaltout Hossam A , Fortunato John E , Diz Debra I
Published: July 2021

Fludrocortisone (Florinef) is commonly used to treat symptoms associated with postural orthostatic tachycardia syndrome (POTS). We have previously shown that Florinef treatment in children with POTS improved the changes in baroreflex sensitivity (BRS) and heart rate variability (HRV) measured as the root of mean square of successive differences (rMSSD) during upright tilt compared to untreated children with POTS. We noticed that a subgroup of our patients experienced POTS symptoms followed by syncope at later time points during the 45 min tilt test in both Florinef treated and untreated groups. We stratified based on syncope and compared the effect of Florinef treatment on both groups. Of the 32 POTS patients studied (15.0 ± 0.6 yrs old), 14 were treated with Florinef of whom 5 had syncope, and 18 were untreated of whom 5 had syncope. In the non-syncopal group, subjects treated with Florinef for a minimum of 4 wks compared with untreated POTS without syncope had similar baseline supine measures of MAP, HR, BRS and HRV before tilt, and less reduction in BRS during tilt measured as Seq UP (-7.1 ± 2.5 vs -15.1 ± 3.5 ms/mmHg; p<0.03), a trend for less attenuation in HRV (-22.4 ± 6.4 vs -35.3 ± 6.3 ms; p<0.07) and reduced tachycardia with tilt (25 ± 6 vs 38 ± 4 beats/min; p<0.02) compared with the untreated group. Meanwhile, in the syncopal group, Florinef-treated patients at baseline in the supine position before tilt had worse BRS function measured as Seq UP compared to untreated (11.9 ± 2.2 vs 26.0 ± 6.7 ms/mm Hg; p<0.04), a tendency for lower HRV (40.8 ± 7 vs 61.2 ± 12 ms; p<0.08) and higher HR (82 ± 3 vs 65 ± 7 beats/min; p<0.02) than untreated POTS patients with syncope. In contrast to non-syncopal POTS, the HR increase during tilt in syncopal POTS subjects was not reduced by the Florinef. The impairments in baseline supine autonomic function in POTS with syncope patients treated with Florinef relative to untreated patients and lack of improvement in the performance upon upright tilt suggests that POTS patients should be stratified by syncope status during the tilt test prior to assigning this treatment regimen. Additional studies are needed to better define these patients and to determine if other pharmacologic agents would provide a more optimal treatment. Support: AHA12CRP9420029
Abstract 306: China Observational Study on Efficacy and Safety of Valsartan/Amlodipine Single-Pill Combination in Treating Patients with Blood Pressure Uncontrolled by Monotherapy (China STATUS II): Interim Analysis
Authors: Hu Dayi , Liu Lisheng , Li Weimin
Published: July 2021

BACKGROUND
Single-pill combination (SPC) in hypertension treatment has been recommended in guidelines for its benefits on improving blood pressure (BP) control and reducing adverse events (AEs) by simplifying treatment.

OBJECTIVE
To evaluate efficacy and safety of valsartan/amlodipine SPC on BP control in Chinese hypertensive patients in a real-life practice setting.

METHODS
This is a multicenter, open-label, observational study in Chinese hypertensive patients. Adults (18 and older) who were not at BP goal (<140/90 mmHg for uncomplicated patients, and <130/80 mmHg for patients with diabetes and chronic kidney disease) on monotherapy were eligible to the study. Patients were treated with valsartan/amlodipine 80/5 mg SPC and were followed over 8 weeks with approximately monthly intervals between clinic visits. For patients not achieving BP goal at week 4, other antihypertensives might be added.

RESULTS
A total of 11,879 patients were recruited into the study. In this interim analysis (from October 12, 2010 to October 11, 2011), a total of 4,609 patients were included. Among them, 39 were excluded due to violation of inclusion criteria, 20 discontinued (9 due to AEs). In total, 4,562 were included in the analysis. Mean age was 57.6 years, 7.1% (324 of 4562) of patients aged ≥80. Overall, mean BP was reduced from 159.7/95.6 mmHg at baseline to 132.0/80.3 mmHg at week 8 (-27.7/-15.3 mmHg, P<0.0001). The magnitude of BP reduction increased by severity of baseline BP. Blood pressure goal was achieved in 67.4% (3076 of 4562) of patients. In patients aged 80 or over, 65.1% (211 of 324) achieved BP goal. Add-on antihypertensives were prescribed in 6.2% (283 of 4562) of patients with diuretics the most often used. Adverse events were reported in 2.2% (99 of 4604) of patients. Edema was reported in 12 patients (0.3%). Three patients experienced serious AEs, of which none were trial drug related. In patients aged ≥80, AEs were reported in 1.2% (4 of 327) of patients, with 2 trial drug related AEs (0.61%), 1 of hypotension and 1 of flush.

CONCLUSION
In this 1
st
largest observational study in Chinese hypertensive patients, the interim analysis results showed that valsartan/amlodipine SPC was effective and safe on BP control in Chinese patients, as well as in patients aged 80 and over.
Abstract 308: Losartan Increases Muscle Insulin Delivery via Microvascular Recruitment and Rescues Insulin’s Metabolic Action during Lipid Infusion
Authors: Wang Nasui , Chai Weidong , Zhao Lina , Liu Zhenqi
Published: July 2021

Rationale:
Insulin delivery and transendothelial insulin transport are two discrete steps that limit muscle insulin action. Angiotensin II type 1 receptor (AT
1
R) blockade recruits microvasculature and increases glucose use in muscle. Increased muscle microvascular perfusion is associated with increased muscle delivery and action of insulin.

Objective:
To examine the effect of acute AT
1
R blockade on muscle insulin uptake and action in rats.

Methods and Results:
Rats were studied after an overnight fast to examine the effects of losartan on muscle insulin uptake (protocol 1), microvascular perfusion (protocol 2), and insulin’s microvascular and metabolic actions in the state of insulin resistance (protocol 3). Endothelial cell insulin uptake was assessed using
125
I-insulin as tracer. Systemic lipid infusion was used to induce insulin resistance. Losartan significantly increased muscle insulin uptake (∼60%, p<0.03), which was associated with 2-3-fold increase in muscle microvascular blood volume (MBV, p=0.002) and flow (MBF, p=0.002). Losartan ± angiotensin II had no effect on insulin internalization in cultured endothelial cells. Lipid infusion abolished insulin-mediated increases in muscle MBV and MBF, and lowered insulin-stimulated whole body glucose disposal (p=0.0001) which were reversed by losartan administration. Inhibition of nitric oxide synthase abolished losartan-induced muscle insulin uptake and reversal of lipid-induced metabolic insulin resistance.

Conclusion:
AT
1
R blockade increases muscle insulin uptake mainly via microvascular recruitment and rescues insulin’s metabolic action in the insulin resistant state. This may contribute to the clinical findings of decreased cardiovascular events and new onset of diabetes in patients receiving AT
1
R blockers.
Abstract 320: Urinary Albumin Excretion at Follow Up Predicts Cardiovascular Outcomes in Subjects With Resistant Hypertension
Authors: Oliveras Anna , Armario Pedro , Sierra Cristina , Arroyo José , Hernández del Rey Raquel , Vázquez Susana , Larrousse María , Sans Atxer Laia , Roca-Cusachs Alexandre , de la Sierra Alejandro
Published: July 2021

Renal function and albuminuria predict CV disease in general population, but their predictive value in resistant hypertension (RH) is rather unknown.

Aim:
to determine the ability of renal parameters to predict adverse CV outcomes in RH patients.

Methods:
One hundred thirty-three (59% males, aged 61yr) RH pts. (BP ≥140/90 mmHg despite treated with ≥3 antihypertensive drugs) were evaluated. Mean follow-up: 88±5 months. Primary composite end-point: first occurrence of a CV event (nonfatal myocardial infarction, nonfatal stroke, new-onset heart failure, coronary or peripheral by-pass) or CV death. Renal function was assessed by serum creatinine, creatinine clearance (CrCL) and urine albumin/creatinine ratio (UACR). Microalbuminuria (MAB) was defined as UACR >30mg/g.

Results:
Twenty-two subjects (16.5%) reached the primary end-point. After adjustments for previous CV disease, systolic BP both at baseline and during follow-up and CrCl, high UACR during follow-up was significantly associated with a worse CV outcome (Table). More patients who had a CV event developed MAB at follow-up (28% vs. 6%), whereas the proportion with MAB regression in this group was lower (11% vs. 19%); p=0.005. Although renal function was also associated with outcome in unadjusted analyses, the significance was lost after baseline risk and BP adjustment.

Conclusion:
in patients with resistant hypertension, microalbuminuria at follow-up but not at baseline independently predicts CV outcomes.

* adjusted for SBP both at baseline and during follow-up and previous CV disease

** adjusted for the aforementioned confounders plus CrCl both at baseline and at follow-up; UACR tested after log transformation.
Abstract 341: Synergistic Effects of Renal Dopamine and Gastrin Receptors in Hypertension
Authors: Chen Yue , Zhen Shuo , Asico Laureano , Jose Pedro , Zeng Chunyu
Published: July 2021

Oral NaCl produces stronger natriuresis and diuresis as compared with venous infusion of same amount of NaCl, indicating the existence of renal-gastric axis. Although numerous hormones are secreted in gastrointestinal tract, gastrin is evident one due to its natriuretic effects and taken-up by the renal proximal tubule (RPT) cells. We hypothesize that there is an interaction between gastrin and dopamine receptor in kidney, which synergistically increases sodium excretion, the impaired interaction would be involved in the pathogenesis of hypertension. In WKY rats, infusion of gastrin, via renal artery, induced natriuresis and diuresis, which was blocked in the presence of CI988, a gastrin receptor blocker. Similarly, the natriuretic and diuretic effect of fenoldopam, a D1-like receptor agonist, was blocked by the D1-like receptor antagonist,
SCH23390
, indicating that gastrin and fenoldopam, via individual receptor, play natriuretic and diuretic effects. Our further study found that lower dosages of gastrin or fenoldopam could not induce natriuresis and diuresis alone, while putting together induced natriuretic and diuretic effects. The above-mentioned effects were lost in SHRs. We also found, in the presence of
SCH23390
, gastrin-mediated natriuresis and diuresis was partially blocked. Similarly, in the presence of CI988, the natriuretic and diuretic effects of fenoldopam were partially blocked, indicating the interaction between gastrin and D1-like receptor. The gastrin/D1-like receptor interaction was also confirmed in the RPT cells. Stimulation of one receptor increased the expression of the other. Stimulation of either D1-like receptor or gastrin receptor inhibited the Na
+
-K
+
-ATPase activity in RPT cells, while in the presence of
SCH23390
, the inhibitory effect of gastrin on Na
+
-K
+
-ATPase activity was partially blocked. In the presence of CI988, D1-like receptor-mediated inhibitory effect of Na
+
-K
+
-ATPase activity in RPT cells was partially inhibited. It indicated the synergistic effect between gastrin and D1-like receptor would increase the sodium excretion in WKY rats; the impaired interaction might be involved in the pathogenesis of hypertension.
Abstract 35: Transplantation of Mesenchymal Stem Cells into the Renal Medulla Attenuated Salt-sensitive Hypertension in Dahl S Rat
Authors: Hu Junping , Zhu Qing , Han Wei-Qing , Li Pin-Lan , Li Ningjun
Published: July 2021

Transplantation of mesenchymal stem cells (MSCs) has been employed as a therapeutic strategy for many different diseases. We have recently shown that there is a stem cell dysfunction in the renal medulla that may contribute to the development of salt-sensitive hypertension in Dahl S rats. The present study tested the hypothesis that transplantation of MSCs into the renal medulla improves salt-sensitive hypertension in Dahl S rats. Rat adult MSCs were obtained from Texas A&M Health Science Center, ex-vivo expanded and infused (5 million cells) into the renal medulla in uninephrectomized Dahl S rats, which were then treated with low salt (LS, 0.4% NaCl) or high salt (HS, 8% NaCl) diet for 10 days. Results showed that the mRNA levels of stem cell markers CD133 and CD90 were increased by 60% and 70%, respectively, in the renal medulla in MSC-treated rats compared with control cell-treated rats. HS challenge increased mean arterial blood pressure in control cell-treated animals (from 113.9 ± 3.4 to 153.5 ± 4.8 mmHg), which was significantly attenuated in MSC-treated animals (from 114.1 ± 3.5 to 131.3 ± 2.5 mmHg). Meanwhile, ELISA analysis showed that the levels of pro-inflammatory cytokine interleukin-1β in the renal medulla were remarkably increased in HS-treated rats compared with LS-treated rats, which was blocked in MSC-treated rats (1.81 ± 0.18 ng/mg protein in LS group, 2.84 ± 0.57 in HS +control cell and 1.83 ± 0.35 in HS+MSC). Furthermore, immunostaining showed that the significant increase in immune cell (CD43+) infiltration into the renal medulla in HS control rats was reduced in HS+MSC rats. These results suggest that correction of stem cell dysfunction in the renal medulla attenuated inflammation in this kidney region after HS challenge and improved high salt-induced hypertension in Dahls S rats, which may serve as a therapeutic approach for salt-sensitive hypertension (supported by NIH grant HL89563 and HL106042)
Abstract 362: G Protein-Linked Receptor Kinase 4 is Palmitoylated and Acetylated and Regulates Subcellular Localization in Human Renal Proximal Tubule Cells
Authors: Gildea John J , Hou Christine L , Zhenyue Huang , Felder Robin A
Published: July 2021

G protein-linked receptor kinase 4 (GRK4) is a kinase expressed in human renal proximal tubule cells (RPTC). Three single nucleotide polymorphisms in this gene are associated with hyper-phosphorylation and inactivation of the dopamine-1 receptor (D1R), and are associated with both hypertension and salt sensitivity. GRK4 is a prime therapeutic target for hypertension so we sought to discover potential post-translational modifications that could affect both localization and function. We identified two unique posttranslational modifications of GRK4 that we hypothesize are associated with protein localization. GRK4 is found at the plasma membrane (PM), in the cytoplasm and in the nucleus. We determined that GRK4 is both acetylated and palmitoylated. Using cell fractionation and immunoprecipitation, we determined that GRK4 was found in the nucleus, but acetylated GRK4 was only found in the cytoplasmic fraction using six different human RPTC cell lines (>10 fold n=6, p<0.01). We previously reported that PM GRK4 internalized following fenoldopam (FEN, dopamine agonist) stimulation, but the internalization only occurred in normally coupled human renal proximal tubule cells (nRPTC), not uncoupled cells (uRPTC). GRK4 is palmitoylated at the C-Terminal end of the protein (cystein 563, GGCPalmLTMVP). Using the palmitic acid tracer, 17-octadecynoic acid (17-ODYA) and Huisgen’s cycloaddition reaction (Click Reaction Chemistry) and biotin-azide for detection, we determined that GRK4 is depalmitoylated in a FEN (1μM, 30 min) and cAMP (forskolin, 10 μM, 30 min.) dependent manner. The amount of palmitoylated GRK4 was decreased following treatment with FEN (28.4%±3.6, n=3, p<0.01 vs VEH) or forskolin (35.3%±6.7, n=3, p<0.05 vs VEH) in nRPTC. No significant change in GRK4 palmitoylation was observed in uRPTC. The depalmitoylation of GRK4 correlates with its change in plasma membrane localization in both nRPTC and uRPTC. In conclusion we have determined for the first time that GRK4 is acetylated and the acetylated GRK4 is found only in the cytoplasmic fraction. In addition we have determined for the first time that GRK4 is depalmitoylated in nRPTC (not in uRPTC) when stimulated with FEN and this effect was mimicked by increasing intracellular cAMP using forskolin.
Abstract 379: Insulin Attenuated Albuminuria by Upregulating Angiotensin Converting Enzyme 2 (ACE2) in Type 1 Diabetic Akita Mice
Authors: Salem Esam , Somineni Hari K , Chodavarapu Harshita , Morris Mariana , Elased Khalid M
Published: July 2021

Diabetic nephropathy (DN) is a microvascular complication of diabetes that is clinically diagnosed by a progressive increase in albuminuria. Alterations within renin angiotensin system balance contribute to the pathogenesis of diabetic kidney disease. Angiotensin converting enzyme 2 (ACE2), a metallocarboxypetidase, has a renoprotective role due to its ability to form Angiotensin (1-7) [Ang-(1-7)] by degrading Angiotensin II (Ang II). Accumulating evidence shows that strict glycemic control attenuates diabetic kidney damage. Therefore, the aim of this study is to test the hypothesis that normalizing hyperglycemia with insulin will reduce albuminuria by increasing ACE2 in Akita diabetic mice. Type 1 diabetic Akita mice (C57BL/6-Ins2Akita/J) and their wild type (WT) littermates were used. Metabolic parameters were monitored weekly. Urine was collected over 24 hours to measure the urinary albumin, total protein and ACE2 activity. Akita mice developed significant hyperglycemia (Akita: 452±6; WT: 118±2 mg/dL), hypoinsulinemia (Akita: 0.5; WT: 1.5 ng/mL) and hypoadiponectinemia (Akita: 3.0; WT: 6.0 μg/mL) compared to WT mice. There was a significant increase in urinary albumin excretion (Akita: 2.1±0.2; WT: 0.2±0.06 mg/day) in Akita mice compared to WT mice. In addition, Akita mice demonstrated a significant decrease in renal (Akita: 3±0.3; WT: 4.1±0.1 pmol/hr/μg protein) and urinary (Akita: 0.2±0.03; WT: 0.7±0.1 pmol/hr/μg protein) ACE2 activity compared to WT mice (P<0.05). Western blot & immunohistochemistry revealed downregulation of renal ACE2 & nephrin protein expression in Akita mice compared to WT mice. Treatment with insulin implants (LinβitR) for 10 weeks significantly decreased hyperglycemia in Akita mice (treated: 135±21; untreated: 452±6 mg/dL). Insulin treatment significantly decreased urinary albumin excretion (treated: 0.18±0.2; untreated: 2.1±0.2 mg/day) and increased urinary ACE2 activity (treated: 1.3±0.3; untreated: 0.2±0.03 pmol/hr/μg protein) in Akita mice. In conclusion, normalizing hyperglycemia in Akita mice with insulin increased ACE2 activity and attenuated albuminuria.
Abstract 4: Genetic Deletion of CD247 in Dahl Salt-Sensitive (SS) Rats Attenuates Hypertension and Renal Damage
Authors: Mattson David L , Lund Hayley , Guo Chuanling , Geurts Aron , Jacob Howard
Published: July 2021

The CD3 zeta chain (CD247), a gene involved in T cell signaling, has been demonstrated to associate with hypertension in human genetic studies. Hypertension and renal damage in the Dahl SS rat are associated with an increase in infiltrating T cells in the kidney. There are numerous descriptions of the role of CD247 as a modulator of T cell receptor signaling, but little is known about the role of this gene product in hypertension. To test the functional role of CD247 in hypertension and renal disease, zinc finger nucleases targeting exon 1 were injected into Dahl SS/JrHsdMcwi embryos. The resulting mutation is a 13-bp frameshift deletion of bases 155-167 in exon 1 of CD247 leading to a predicted stop codon within 19 bases of the mutation. Western blotting confirmed the absence of CD247 protein in the thymus, demonstrating a null mutation, and flow cytometry of circulating T and B-cells in wild type (WT) and CD247 null mutant rats (n=5-10/group) demonstrated that the mutants have a significant decrease in CD3+ T-cells (0.04±0.01 vs 4.6±0.5 x 10
7
cells/ml) and increased CD45R+ B-cells (4.1±0.4 vs 1.2±0.2 x 10
7
cells/ml). Studies were then performed on age-matched, male, WT and CD247 null mutant rats fed a 4.0% NaCl diet for three weeks. The infiltration of CD3+ T-cells into the kidney following high salt was significantly blunted in the CD247 mutant rats (1.4±0.4 x 10
5
cells/kidney) compared to the WT (8.7±2.0 x 10
5
cells/kidney). Accompanying the reduced infiltration of T-cells, mean arterial blood pressure was significantly lower in the CD247 null mutant rats than the WT (134±1 vs 151±2 mmHg). As an index of kidney disease, urinary albumin and protein excretion rate were significantly reduced in CD247 null mutants (17±1 and 62±2 mg/day, respectively) compared to WT (49±3 and 121±5 mg/day, respectively). Finally, a histological analysis revealed that the glomerular and tubular damage in the kidneys of the WT rats fed high salt was also attenuated in the CD247 null mutants. This new experimental model provides evidence that T cells are required for the full development of Dahl SS hypertension and indicate that the association between CD247 and hypertension in humans may be related to altered immune cell function. Supported by HL-29587, DK-62803, and RC2-HL101681.
Abstract 401: Prostaglandin E2 Stimulates Renin Synthesis in Mouse Collecting Duct M-1 Cells via Ep1 Receptor Through Pkc/camp/creb Pathway
Authors: Gonzalez Alexis A , Leach Dan , Navar L G , Prieto Minolfa C
Published: July 2021

Prostaglandin E2 (PGE2) plays a major role in regulating renin expression and release by the renal juxtaglomerular (JG) cells. Recently it has been demonstrated that PGE2-dependent upregulation of renin in JG cells is mediated by activation of E prostaoind receptor type 4 (EP4) via cAMP accumulation. Renin is also produced by the principal cells of the collecting ducts (CD) and is upregulated during angiotensin II-dependent hypertension. However, the effects of PGE2 on CD renin remain unknown. Four types of receptors have been described in rat and mouse CD, EP1, EP3 and EP4. Here, we tested the hypothesis that renin is upregulated by PGE2 via activation of EP receptors in mouse CD M-1 cells. By immunostaining we confirmed the presence of EP1, EP3 and EP4 receptors, while EP2 was not detected. A dose response treatment with PGE2 showed increased levels of renin mRNA and protein with a maximum response at 1 μmol/L (mRNA: 19.3 ± 3.0; P<0.05; protein: 3.01 ± 0.08 fold change; P<0.05). To assess which EP receptor is involved in the renin upregulation we used specific EP receptor antagonists: ONO-8711 (EP1; 10 nmol/L), L-798106 (EP3; 10 μmol/L) and AH 23848 (EP4; 10 μmol/L). EP1 antagonist suppressed the PGE2-mediated upregulation of collecting duct renin mRNA and protein (mRNA: 1.0 ± 0.2; protein: 0.98 ± 0.13 fold change; P=NS), while EP4 antagonist only partially decreased it (mRNA: 11.2 ± 2.8; P<0.05; protein: 2.81 ± 0.07 fold change; P<0.05). EP3 antagonist exacerbated the PGE2 mediated-upregulation of renin (mRNA: 50.3 ± 6.0; P<0.05; protein: 3.56 ± 0.08; fold change; P<0.05). Because EP1 is a Gq linked receptor that activates PKC, we further assessed the effects of PKC inhibition using calphostin C and a PKCα dominant negative (DN) on renin expression. Calphostin C and PKCα-DN blunted the PGE2-induced renin upregulation. Importantly, the increases in cAMP levels and phosphorylation of the cAMP response element-binding transcription factor (CREB) mediated by PGE2 were also prevented by both treatments. The results indicate that in mouse CD cells, EP1 receptor activation upregulates renin synthesis via PKC/cAMP/CREB, suggesting that the presence of PGE2 in renal medullary tissues may contribute to the stimulation of collecting duct renin.
Abstract 413: Electroacupuncture Improves Arterial Baroreflex and Chemoreflex Sensitivity in Angiotensin II-induced Hypertension in Rats
Authors: Zhang Qi , Tan Yingying
Published: July 2021

Despite the use of electroacupuncture (EA) to treat a number of cardiovascular diseases, little is known about the mechanisms that underlie its actions. It is well known that renin-angiotensin system plays a major role in pathogenesis of hypertension. The purpose of this study was to examine the influence of EA stimulation of ST 36 on arterial baro- and chemoreflex sensitivity in angiotensin (Ang) II-induced hypertension in rats. Four groups of SD rats (n=8/group) were implanted with subcutaneous osmotic minipumps for infusion of Ang II (300 ng/kg/min) or saline control, with or without EA stimulation. EA groups underwent a 2 Hz EA treatment at the acupoints ST36 or a non-acupoint with the intensity increasing stepwise from 0.5-1-1.5 mA once a day for 30 min. Baroreflex sensitivity index was calculated on the basis of reflex changes in heart rate (HR) related to the arterial pressure (AP) changes induced by phenylephrine or sodium nitroprusside injection, and chemoreflex sensitivity was evaluated by intravenous injections of increasing doses of potassium cyanide (KCN). After 4 weeks of treatment, Ang II significantly increased mean arterial pressure (107±2 and 139±2 mmHg in control vs. Ang II group). Baroreflex sensitivity to AP rises and falls were also impaired in Ang II infusion group (1.3±0.08 and 2.1 ±0.18 bpm/mmHg) compared with those in control group (1.7±0.08 and 2.7±0.06 bpm/mmHg). EA stimulation of ST 36 on Ang II infusion rats significantly improved the impaired baroreflex sensitivity (1.7±0.06 and 2.6±0.1 bpm/mmHg, P < 0.05). In addition, the bradycardic and pressor responses evoked by KCN injections were attenuated in Ang II infusion rats (23±9 bpm and 7±1 mmHg in Ang II group vs. 78±7 bpm and 22±3mmHg in control group, P < 0.05), while EA stimulation improved both chemoreflex responses in AngII rats (84±15 bpm and 32±5 mmHg, P<0.05). In contrast, EA stimulation had no significant effect on control group. These results indicate that EA stimulation improves arterial baroreflex function and chemoreflex sensitivity in conditions of high Ang II.