bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract P244: Characterization of Exosomes From Vascular Endothelial and Smooth Muscle Cells
Authors: Boyer Michael , Eguchi Satoru , Rizzo Victor , Baggette Ariel , Scalia Rosario
Published: March 2022

Exosomes are small nanovesicles derived from endosomal compartments termed multivesicular bodies. These multivesicular bodies fuse with the plasma membrane, release exosomes into extracellular space, allowing them to transport their cargo of functional nucleic acids and proteins. Despite their well-documented existence, not much is known about exosomes in vascular biology. The luminal surface of the intima consists of a confluent monolayer of endothelial cells (ECs), while the medial layer is characterized by presence of vascular smooth muscle cells (VSMCs). We characterized the exosomes released by these cell types in culture to better understand the packaging of these vesicles and their capacity to participate in cell-to-cell communication. Rat aortic ECs exosomes were generated in serum-free media for 48 hours while rat aortic VSMC exosomes were generated in serum-free media for 72 hours. Media harvested from both was ultracentrifuged at 10,000xg to remove microparticles followed by centrifugation of the supernatant at 100,000xg to pellet exosomes. Exosome pellet was re-suspended in PBS, 0.22 μm filtered and spun at 100,000xg to remove contaminating particles. Transmission electron microscopic analysis of VSMC exosomes confirmed particle morphology with diameters ranging from 60-150 nm. Particle size and concentration was determined using NTA NanoSight. The modal size of EC exosomes and VSMC exosomes were 107.2±5.4 nm and 116.6±7.5 nm, respectively. Western blotting analysis was performed to characterize common and specific markers for vascular exosomes. We confirmed common exosome markers such as CD81, CD63, caveolin-1, and flotillin-1 in both populations. ECs specifically expressed VE-cadherin and TSG-101 whereas VSMCs expressed syntenin-1 and smooth muscle actin. Cell-to-cell signaling
in vitro
assays revealed that EC-derived exosomes can stimulate hypoxia-inducible factor 1-alpha expression in VSMCs in a dose-dependent and time-dependent manner. Maximal induction was seen at 6 hours of stimulation and using 5x10
8
particles/mL. From these data, we conclude that exosomes are released from these cell types and play a potential role in cell-to-cell communication to maintain homeostasis and/or promote pathology.
Abstract P262: Vasopressin Receptors Regulate Immune Responses in Preeclampsia
Authors: Scroggins Sabrina M , Santillan Donna A , Gomendoza Daffney T , Gravatt Lindsay K , Huber-Keener Kathryn J , Perschbacher Katherine J , Sandgren Jeremy A , Devor Eric J , Grobe Justin L , Santillan Mark K
Published: March 2022

The pathogenesis of preeclampsia (PE) involves imbalanced T helper (T
H
) cell populations and resultant changes in pro- and anti-inflammatory cytokine release. Elevated secretion of arginine vasopressin (AVP) precedes the development of symptoms in PE in humans, and chronic infusion of AVP (24 ng/hr s.c.) throughout gestation is sufficient to initiate cardiovascular, renal, and immune phenotypes of PE in wild-type C57BL/6J mice.
We hypothesize that increased AVP signaling may mediate the immune changes observed in PE.
AVP infusion throughout gestation in mice resulted in increased pro-inflammatory IFNγ (T
H
1) in the maternal plasma (N=7, p<0.05) and IL-17 (T
H
17) in the placenta (N≥10, p<0.001). The T
H
2-associated anti-inflammatory cytokines IL-4 and IL-10 were decreased in maternal kidney (IL-4: N=8, p<0.05; IL-10: N=5, p<0.01) and fetal kidney (IL-4: N=5, p<0.05; IL-10: N=5, p<0.05) of AVP-infused dams.
To elucidate the receptor dependency of these effects,
AVP-infused dams were simultaneously treated with chronic infusion of AVP V
1A
and/or V
2
receptor antagonists (22 ng/hr s.c). Combined blockade of V
1a
+V
2
receptors by conivaptan, as well as specifically blocking V
2
by tolvaptan, corrected AVP induced reductions in IL-4 in maternal (conivaptan: N=5, p<0.05; tolvaptan: N=5, p<0.0.0001) and fetal kidneys (conivaptan: N=5, p<0.0001; tolvaptan: N=5, p<0.05). These data implicate V
2
as the receptor involved in kidney IL-4 deficiency in PE, whereby blockade of V
2
restores IL-4, preventing inflammation. Combined blockade of V
1A
+V
2
receptors by conivaptan corrected the placental loss of IL-4 (N=5, p<0.05), whereas blockade of either receptor alone was insufficient, suggesting loss of placental IL-4 via AVP is mediated by both V
1a
and V
2
receptors. In contrast, increased placental IL-17 was only corrected by selective blockade of V
1A
by relcovaptan (N=5, p<0.05), suggesting a novel role for V1a receptor in pro-inflammatory placental IL-17 production in PE. Collectively these results demonstrate the sufficiency of AVP to induce the immune changes typical of PE, and support a dominant role for V
1A
in the induction of pro-inflammatory IL-17 (T
H
17) release versus a dominant role for V
2
receptors in the suppression of anti-inflammatory IL-4 (T
H
2) release.
Abstract P263: Interleukin-17 Infusion Promotes Cerebral Edema and Increased Blood Brain Barrier Permeability in Pregnant Rats
Authors: Warrington Junie P , Duncan Jeremy , Drummond Heather A , Granger Joey P , Ryan Michael J
Published: March 2022

While cerebrovascular abnormalities such as cerebral edema and increased blood-brain barrier (BBB) permeability are a common complication of (pre)eclampsia, the exact mechanisms underlying these abnormalities remain unclear. One potential mechanism could be increased Interleukin-17 (IL-17), a pro-inflammatory cytokine that is increased in both preeclampsia patients and the rat model of placental ischemia created by reducing uterine perfusion pressure. While IL-17 has been linked to the pathogenesis of preeclampsia, its effect on cerebrovascular function during pregnancy is unknown. Thus, we tested the hypothesis that increasing circulating IL-17 during pregnancy promotes regional increases in brain water content and BBB permeability. Recombinant mouse IL-17 (150 pg/day) was infused via mini-osmotic pump (i.p) from gestational day 14 to 19 in pregnant rats (n = 5-7 per group). Brain water content was assessed using the dry weight to wet weight ratio and BBB permeability was assessed by quantifying Evans blue extravasation into the anterior cerebrum, hippocampus, cortex, striatum, posterior cerebrum, and cerebrum. As reported previously, IL-17 infusion resulted in a significant increase in mean arterial pressure (119 ± 3 vs. 104 ± 4 mmHg in normal pregnant group; p = 0.010). Water content tended to be increased in the cortex (80.5 ± 0.2 vs. 79.5 ± 0.4%, p = 0.054) and striatum (77.6 ± 0.8 vs. 75.1 ± 1.4%, p = 0.062) and was significantly increased in the posterior cerebrum (79.7 ± 0.4 vs. 77.8 ± 0.5%, p = 0.007) and cerebrum (79.8 ± 0.3 vs. 78.8 ± 0.1%, p = 0.005) of the IL-17 treated group. BBB permeability was increased only in the cortex (0.017 ± 0.002 vs 0.012 ± 0.002, p = 0.046) of rats receiving IL-17 infusion. These data suggest that increased IL-17 during pregnancy contributes to edema formation and increased BBB permeability in the cerebral cortex and may be a therapeutic target in preeclampsia. Future studies will determine whether reducing IL-17 levels in placental ischemic rats will prevent these cerebrovascular changes.
Abstract P273: Association Between 24-hr Urinary Cortisol and Severity of Obstructive Sleep Apnea in Patients With Resistant Hypertension
Authors: Valaiyapathi Badhma , Siddiqui Mohammed , Judd Eric , El Hachem Maria , Oparil Suzanne , Calhoun David A , Dudenbostel Tanja
Published: March 2022

Background:
Plasma cortisol levels have been found to be negatively associated with severity of obstructive sleep apnea (OSA) based on morning salivary cortisol levels. Studies on pediatric patients have suggested that salivary cortisol can be used as a biomarker for assessment of OSA severity and to analyze prognosis following treatment with continuous positive airway pressure (CPAP). We hypothesized that 24-hr urinary cortisol levels are associated with severity of OSA in patients with resistant hypertension (HTN).

Methods:
In this prospective study, 197 patients were recruited from University of Alabama at Birmingham resistant HTN clinic. Office blood pressure (BP), diagnostic polysomnogram (PSG), 24-hr urine analysis for cortisol were done in these patients as part of study protocol. Patients with a diagnosis of OSA who were already treated with CPAP were excluded.

Results:
Out of 116 patients who were analyzed based on inclusion criteria, 53.5% were female, 62.1% were African American and the mean baseline values were age 57.4 ± 10.6 in years, body mass index 34.9 ± 7.4 kg/m
2
, 24-hr urinary cortisol 12.1 ± 7.7 mcg, apnea-hypopnea index (AHI) 9.4 ± 13.0 events/hr. Regression analysis was done between 24-hr urinary cortisol and AHI, and the Pearson correlation coefficient was 0.0498 (p = 0.602). There was no significant correlation between 24-hr urinary cortisol level and increasing AHI.

Conclusion:
In this cross-sectional study, 24-hr urinary cortisol level was not significantly associated with increasing AHI, indicating that 24-hr urinary cortisol may not play a role in the severity of OSA in patients with resistant HTN.
Abstract P277: Mineralocorticoid Receptor Signaling Regulates TRPV4-mediated Vasodilation of Parenchymal Arterioles
Authors: Diaz-Otero Janice M , Yen Ting-Chieh , Jackson William F , Dorrance Anne M
Published: March 2022

Hypertension impairs endothelium-dependent dilation of the parenchymal arterioles (PA) that regulate white matter perfusion. In the periphery, mineralocorticoid receptor (MR) activation facilitates hypertension-associated artery dysfunction; the role of MR signaling in PA dysfunction has not been defined. We hypothesized that Angiotensin II (AngII)-hypertension impairs TRPV4-mediated dilation in an MR-dependent manner. 16 week old male C57bl/6 mice were treated with AngII (800ng/kg/min) ± the MR antagonist, eplerenone (EPL; 100mg/kg/day) for 4 weeks; Sham mice served as control. PAs were isolated and studied by pressure myography. Data are presented as mean ± SEM; n=4-6 per group. AngII increased systolic blood pressure, an effect not blunted by EPL (Sham:147 ± 3; AngII: 177* ± 3; AngII+EPL: 182* ± 6mmHg; *=p<0.05 vs. Sham). However, EPL prevented the increased myogenic tone (31±1 vs 48*±4 vs 35±3 % tone; *=p<0.05 vs. Sham) and the impaired carbachol (CbCh)-induced dilation (51±3 vs 24*±2 vs 49±3 %dilation; Sham vs. AngII vs. AngII+EPL; *=p<0.05 vs. Sham) caused by AngII infusion. CbCh-induced dilation was unaltered by L-NAME (10
-5
M) and indomethacin (10
-4
M) in all groups (Sham: 51±3 vs. 53±2; AngII:24±2 vs. 28±2; AngII+EPL 49±3 vs. 47±3% dilation; CbCh vs. CbCh+L-NAME+Indomethacin) implicating endothelium-derived hyperpolarization (EDH). In contrast, the TRPV4 antagonist, GSK2193874 (GSK2, 10
-7
M) blunted the CbCh-induced dilation in all groups (Sham: 51±3 vs 13*±8; AngII: 24±2 vs 7*±2; AngII+EPL: 49±3 vs 16*±4 % dilation; CbCh vs CbCh+GSK2 ;*=p<0.05). In the AngII and AngII+EPL mice, TRPV4 inhibition reduced myogenic tone (AngII: 16±3; AngII+EPL: 17±6 %tone loss; p<0.05), an effect that was not observed in the Sham mice (2±3 %tone loss). AngII infusion decreased cerebral perfusion; EPL prevented this decrease (Sham: 938±32; AngII:596*±53; AngII+EPL:793±36 perfusion units; *=p<0.05 vs. Sham). MR activation regulates TRPV4 signaling in PAs during AngII-infusion, independent of hypertension. Impaired TRPV4 function plays a critical role in AngII-hypertension-associated changes in PA reactivity and may increase the risk of small vessel disease.
Abstract P286: Circulating Lipoxin A4 Causes Resolution of Inflammation via Estrogen Receptor Activation, While Mitochondria N-Formyl Peptides Induce Inflammation via Formyl Peptide Receptor in Hypertension
Authors: Wenceslau Camilla F , McCarthy Cameron G , Szasz Theodora , Webb R. Clinton
Published: March 2022

Recently, we observed that mitochondrial components have inflammatogenic proprieties and that their fragments are elevated in the circulation of spontaneously hypertensive rats (SHR). Also, infusion of mitochondrial N-formyl peptides (F-MITs) into rats induces inflammation and vascular dysfunction via formyl peptide receptor (FPR) activation. In contrast, Lipoxin A4 (LXA4), a mediator of resolution of inflammation, also binds FPR. However, LXA4-FPR-dependent effects seem to be opposite from F-MITs. We first hypothesized that LXA4 is decreased in SHR. We collected plasma from male SHR and Wistar Kyoto rats (WKY) (12 weeks old) and LXA4 was extracted via hydrophobic, reverse-phase, silica-based column. Our initial hypothesis was refuted, since LXA4 was increased in SHR (WKY: 0.33±0.05 vs. SHR: 0.79±0.08 ng/ml, p<0.05). As a result, we inhibited LXA4 synthesis in SHR with a 5-lipoxygenase (5-LOX) inhibitor Zileuton (10mg/kg/day i.p.) for 10 days. 5-LOX blockade did not change blood pressure (BP), but did cause a deterioration of vascular function in intrarenal and mesenteric resistance arteries in SHR. On the other hand, the blockade of FPR in SHR for 10 days with Cyclosporin H (CsH) and WRW4 (0.1 mg/kg/day) reduced BP (telemetry: SHR+control: 151±7.2 vs. SHR+CsH+WRW4: 138±0.4 mmHg, p<0.05) and left ventricle mass. FPR blockade also ameliorated acetylcholine-induced relaxation of intrarenal (Emax: SHR+control: 10±5 vs. SHR+CsH+WRW4: 28±6 %, p<0.05) and mesenteric resistance arteries (Emax: SHR+vehicle: 74±10 vs. SHR+CsH+WRW4: 99±0.6 %, p<0.05). From these data, we suggest that LXA4 does not act on FPR to promote resolution of inflammation. We believe that another factor binds FPR (e.g., F-MITs) and leads to vascular damage in SHR. In support of this, we observed that LXA4 phosphorylates estrogen receptor (ER) alpha
Ser118
in aortic vascular smooth muscle cells (VSMC) and ER antagonist ICI-182 (100nM), but not FPR antagonist, abolishes these responses. On the other hand, FMITs increased phosphoERK 1/2 in VSMC and FPR antagonists blocked this increase. In conclusion, FMITs and LXA4 have opposite effects in SHR. LXA4 induces resolution of inflammation, possibly via ER activation, and F-MITs lead to damage via FPR activation.
Abstract P287: Hypertension and Danger-associated Molecular Patterns
Authors: Bammert Tyler D , Fleshner Monika R , Dow Caitlin A , Lincenberg Grace M , Greiner Jared J , Stauffer Brian L , DeSouza Christopher A
Published: March 2022

Recent advances in immunobiology have established the importance of endogenous self-molecules or danger-associated molecular patterns (DAMPs) in the initiation of various inflammatory processes as well as the development and progression of atherosclerotic cardiovascular disease (CVD). High-mobility group box 1 (HMGB1) and heat shock protein 72 (Hsp72) are prototypical DAMPs that initiate sterile inflammation, drive inflammatory processes and promote atherogenesis. Hypertension is associated with increased inflammatory burden. The mechanisms underlying blood pressure-related inflammatory stress are not fully understood. It is currently unknown whether DAMPs are dysregulated with elevated blood pressure. Accordingly, the aim of this ongoing study is to determine the influence of hypertension, independent of other risk factors, on circulating expression of HMGB1 and Hsp72. To date, 20 sedentary, middle-aged adults have been studied: 10 normotensive (6M/4F; age: 58±2 yr; BMI: 28.0±1.5 kg/m
2
; BP: 112/68±2/1 mmHg) and 10 hypertensive (5M/5F; age: 59±1 yr; BMI: 28.1±1.3 kg/m
2
; BP: 151/92±2/1 mmHg). All subjects were non-smokers, normolipidemic, normoglycemic, non-medicated and free of overt CVD. Plasma concentrations of HMGB1 and Hsp72 were determined by enzyme immunoassay. Circulating concentrations of both HMGB1 (92.2±4.4 vs 69.5±4.3 ng/mL) and Hsp72 (1.6±0.4 vs 0.8±0.1 ng/mL) were significantly higher (35% and 100%, respectively) in the hypertensive compared with normotensive group. HMGB1 concentration was strongly and positively associated with both systolic (r=0.60; p<0.01) and diastolic (r=0.57; p<0.01) blood pressure; whereas Hsp72 was positively correlated with systolic (r=050; p<0.01) blood pressure only. Elevated circulating concentrations of HMGB1 and Hsp72 are consistent with activation of sterile inflammation pathways that, in turn, promote a hyper-inflammatory state. These initial results suggest that dysregulation of DAMPs may contribute mechanistically to the heightened inflammatory burden associated with hypertension and deserve further study.
Abstract P293: The Correlations Between NT-proBNP and Cardiac Reserve by Phonocardiogram Exercise Test
Authors: Chaoping Yu , Fengcheng Xu , Tianhu Liu
Published: March 2022

Objective:
To investigate the correlations between NT-proBNP and Cardiac contractility reserve index(CCRI) and Cardiac reserve index(CRI) and find more theoretical and clinical evidence that CRI, CCRI can reflect the degree of heart failure,promote the use of them in the Primary hospitals and community health service centers.

Methods:
According to the inclusion and exclusion criteria,155 cases were included in the study, 60 volunteers without cardiovascular disease were selected as the control group, all of them were classed by NYHA functional classification, phonocardiogra were recorded by phonocardiogram exercise test (PCGET) before and after 6 minutes walk test, measured S1 amplitude and heart rate, calculated CCRI, CRI, detected NT-proBNP, and analysed the CCRI, CRI, and NT proBNP correlations.

Results:
Compared with the healthy group, the NT-proBNP, CCRI, CRI, 6 minutes walking distance were significantly different in different NYHA FC, Moreover, with the increase of NYHA FC level, CRI, CCRI gradually decreased, 6 minutes walk distance gradually shortened, NT-proBNP gradually increased, the differences were statistically significant.

Conclusion:
The CCRI, CRI and NT- proBNP have good correlations, so they can reflect the classification of cardiac function, they are facilitate, economic, no invasive, rapid, they are worth using widely in primary hospitals and community health service centers.
Abstract P298: Excretion of Urinary Marinobufagenin And Angiogenic Factors in Pregnancies With Increased Risk for Preeclampsia: A Pilot Study
Authors: Drever Nathan , Wang Hong , Wages John , Yu Bo , Afroze Syeda H , Kalagiri Ram , Larrick James W , Kuehl Thomas J , Uddin Mohammad N
Published: March 2022

Background:
Previous work has shown an increase in urinary excretion of marinobufagenin (MBG) in patients with preeclampsia (preE) compared to normal pregnancy at delivery. MBG is a novel urinary marker for preE; however, it is unknown how MBG levels fluctuate during gestation.

Hypothesis:
Shifts in MBG and angiogenic factors during early pregnancy identify cytotrophoblast’s dysfunction, contributing to reduced vascular development with impaired perfusion and preE.

Methods:
In this study, we prospectively enrolled two groups of patients; 50 patients in each group total of 100 patients for serial collection of urine and serum during each trimester and at delivery. These groups are: (1) Pregnant women at risk for development of preE; and (2) Pregnant women at low risk for development of preE. Risks were calculated for each pregnancy using the sum of relative risk values. Urine samples from 100 subjects (100 in first trimester, 67 in second trimester, 67 third trimester, and 67 at delivery) were assayed using ELISA for MBG (Panorama Research, Inc.), sENG, VEGF, PIGF, sFlt-1 expressed as pg/mg creatinine and the calculated uFP (log of 10x sFLT-1/PIGF ratio). The angiogenic factors were analyzed by commercially available kits.

Results:
Of 100 subjects, 50 had no risk for preE and 50 had relative risks on the average of 6.6 with a range of 1.4 to 16.6. There were no associations between relative risk and any of the 6 angiogenic measures during the first trimester (p > 0.36) and second trimester (p > 0.22) using linear regression. However, during the second trimester, the high risk cohort had lower PIGF levels than the no risk cohort (p < 0.05 using Mann-Whitney U test). Comparing the serial values of 6 angiogenic measures in 67 subjects during the first, second, third trimesters and at deliveries, only MBG and PIGF varied significantly (p < 0.05) with MBG.

Conclusions:
MBG increases with progression of pregnancy and the levels of MBG are the highest during delivery. We conclude that MBG levels increase during normal pregnancy, however, the differential levels of MBG in normal and preE pregnancies are now underway. Relationships to development of preE symptoms and MBG levels are pending with the addition of patients and additional sample.
Abstract P301: Preeclampsia and Gestational Hypertension: Does sEng Levels Make the Important Difference Preeclampsia and Gestational Hypertension: Does sEng Levels Make the Important Difference
Authors: Siddiqui Athar H , Negi Rahul , Haritha Vemanamanda , Aziz Nuzhat
Published: March 2022

The origin of Preeclampsia (PE), a multi-systemic disorder of pregnancy, lies to a great extent on the balance of the anti-angiogenic and angiogenic proteins during pregnancy. In the present study, we have determined the levels of sFlt-1 and sEng levels (anti-angiogenic protein) and Placental Growth Factor, PlGF (angiogenic Protein) in the serum of the patients with hypertensive disorder of pregnancy (including Gestational Hypertension, GH and PE) and Normotensive (NT) pregnancy. The levels of sFlt-1 were found to be significantly higher in the 3
rd
trimester and at term in the hypertensive pregnancy (GH and PE), compared to the NT pregnancy, (8.67±1.93 ng/ml, n=13 vs. 3.95±.37 ng/ml, n=111 at the 3rd trimester and 14.90±2.68 ng/ml, n=15 vs. 6.58±.42 ng/ml, n=111 at term). The levels of sFlt-1 were considerably higher in the PE samples compared to the GH samples, but not significant. Similarly the levels of sEng were found to be significantly higher in the 3
rd
trimester and at term in the hypertensive pregnancy (GH and PE), compared to the NT pregnancy (11.18±1.51 ng/ml, n=15 vs. 7.86±.25 ng/ml, n=106 at the 3
rd
trimester and 12.68±1.70 ng/ml, n=14 vs. 10.01±.42 ng/ml, n=106 at the term). The levels of sEng were, however, found to be significantly higher in all the trimester and at term in the PE samples compared to the NT Samples ( 6.49±1.14 ng/ml, n=7 vs 4.21±.28 ng/ml, n=106, 6.89±2.30 ng/ml, n=7 vs. 3.76±.25 ng/ml, n=106, 13.10±2.12 ng/ml, n=7 vs. 7.86±.37 ng/ml, n=106, 14.93±2.27 ng/ml, n=7, vs. 10.01±.42 ng/ml, n=106 at the 1
st
, 2
nd
, 3
rd
trimesters and term respectively), but not in the GH samples. The angiogenic protein, PlGF was found to be significantly lower in the hypertensive conditions of pregnancy (PE and GH) samples compared to the NT samples, only in the 3
rd
trimester (440±48.58 pg/ml, n=15 vs 1278±104 pg/ml, n=119), although its levels were considerably decreased in the 2
nd
trimester and at term, but not significant. Within the hypertensive conditions of pregnancy, the blood pressure increase at term was more in the PE patients compared to the GH patients (42±5.1/25±3.3 mm Hg vs. 18±3.7/13±3.3 mm Hg,
p<0.05
) compared to the BP recorded at the 1
st
trimester. The results of the present study indicate a more potent role of sEng in the development of PE.
Abstract P309: Alterations In Cardiac Structure And Function Caused By Preeclampsia
Authors: Kraeker Kristin , Herse Florian , Mueller Dominik N , Dechend Ralf , Haase Nadine
Published: March 2022

Preeclampsia is a major cause of maternal and fetal mortality and morbidity and since 2011 the American Heart Association mentioned the history of preeclampsia as a risk factor for later cardiovascular disease. To investigate the cardiovascular impact of preeclampsia, we use a transgenic rat model with females harbouring the gene for human angiotensinogen and males for human renin. After mating the female rat shows typical symptoms of preeclampsia at the end of the second trimester, like high blood pressure, proteinuria or growth restriction of the fetus. With echocardiography analysis a mild, but significant reduced systolic ejection fraction (EF 67.78 ±3.4 vs. 57.11 ±1.8) indicates functional changes. Speckle trackle analysis allows to trace the myocardium over the whole cardiac cycle and gives more sensitive results. A significant decrease in longitudinal (GLS -20.4 ±0.9 vs. -15.5 ±0.6), radial (GRS 26.5 ±4.1 vs. 15.6 ±2.4) and circumferential strain (GCS -22.5 ±0.7 vs. -15.7 ±0.9) and all global strain rates (GLSR -4.9 ±0.3 vs. -3.1 ±0.2; GRSR 4.8 ±0.6 vs. 3.0 ±0.4; GCSR -5.1 ±0.3 vs. -3.8 ±0.3) was measured and describes a reduced myocardial deformation in relation to its original shape and within the speed at which this occurs. This is consistent with a higher relative wall thickness (RWT 0.1875 ±0.007 vs. 0.2205 ±0.009) and an increased perivascular fibrosis (PF 2.58 ±1.4 vs. 3.72 ±1.7) in preeclamptic hearts at the end of pregnancy. This demonstrates extensive alterations in structure and function of maternal hearts caused by preeclamptic pregnancy.
(Values mean ±SEM)
Abstract P313: Age and Response of Plasma Aldosterone to Saline Infusion in Primary Hypertension
Authors: Catena Cristiana , Colussi Gianluca , Novello Marileda , Bertin Nicole , Brosolo Gabriele , Palomba Andrea , Spagnol Francesca , Sechi Leonardo A
Published: March 2022

Objective:
In patients with primary hypertension, plasma aldosterone levels are significantly decreased by an intravenous saline load (IVSL), but this response is variable among patients and related to the ability of salt to modulate aldosterone production. Previous studies have reported that activity of the renin-angiotensin-aldosterone system is related with age. The aim of this study was to investigate whether age might affect the aldosterone response to an IVSL.

Design and Method:
In 124 hypertensive patients (48±13 y, 71 males) who were washed-out of antihypertensive drugs for 2 weeks, we measured renin and PA levels before and after an IVSL (2 lt. saline in 4 h). In all patients secondary causes of hypertension were excluded. For statistical purposes patients were subdivided into two groups based on age (< or > 60 y).

Results:
Twenty-three of 124 patients (18%) were had 60 y of age or more (range 61-77) and the remaining were younger than 60 y (19-60 y). No differences were found between the two groups for gender, body mass index, serum potassium and creatinine clearance. Urinary sodium excretion was comparable in patients older (159±83) or younger (159±66) than 60 y. Baseline PA (76 [49-121] pg/ml) and renin (5.0 [1.9-9.8] mcIU/ml) levels were significantly lower in patients older than 60 y than in those younger than 60 y (115 [77-162] pg/ml, P=0.019; 10.7 [5.1-20.8] mcIU/ml, P=0.026). As expected IVSL decreased significantly (P<0.001) both plasma renin and aldosterone levels. Post IVSL renin was 3.0 [1.1-4.9] mcIU/ml in patients older than 60 y and 6.2 [3.0-12.5] mcIU/ml younger than 60 y. Following IVSL, PA decreased by 87% (10 [10-13] pg/ml) in patients older than 60 y and by 76% (28 [10-49] pg/ml; P=0.003) in patients younger than 60 y. The change in PA induced by IVSL was significantly and inversely related to age (r=-0.185, P=0.039).

Conclusions:
PA levels are lower in hypertensive patients older than 60 y. This difference becomes more relevant after IVSL suggesting greater response of the renin-angiotensin system to volume expansion. This should be taken into account in the diagnostic work-out of hypertensive patients.
Abstract P319: 5-HT7 Receptors Mediate 5-HT-induced Hypotension
Authors: Watts Stephanie W , Seitz Bridget M , Fink Gregory D
Published: March 2022

Serotonin (5-HT, 5-hydroxytrypamine) lowers blood pressure in the conscious rat when given chronically (25 μg/kg/min;
>
24 hours). This same dose of 5-HT nearly normalizes the mean arterial blood pressure of hypertensive rats, including the deoxycorticosterone acetate (DOCA) salt hypertensive rat (baseline =166
+
9 vs 112
+
3 mm Hg). We have found that 5-HT causes venodilation through activation of the 5-HT
7
receptor and presently test the hypothesis that the hypotension stimulated by 5-HT
in vivo
is 5-HT
7
receptor-dependent. Two approaches were made. First, male Sprague Dawley rats were instrumented with radiotelemeters for measurement of blood pressures, HR and activity. Through a venous line, the 5-HT
7
receptor antagonist SB269970 (3 mg/kg, i.v.) was given hours prior to implantation of all rats with an Alzet pump delivering 5-HT (as above). SB269970 abolished the fall in blood pressure during 24 hours of 5-HT-infusion when compared to vehicle (vehicle = -18.73
+
2.0 vs SB269970 = -.7
+
1.51 mm Hg; N=6). Second, we created a global 5-HT
7
receptor knockout (KO) rat through CRISPR-Cas9 technology using a Sprague Dawley background. Genotyping validated creation of deletion of exon 1-2 and/or indel formation on exon 1 and exon 2 of the 5-HT
7
receptor gene. In female KO (N=4) vs WT (N=4), baseline mean arterial blood pressure in radiotelemeter-implanted rats was significantly elevated (KO=111
+
1 mm Hg; WT=103
+
2 mm Hg; p<0.05). Infusion of the same dose of 5-HT (25 μg/kg/min) which lowered mean pressure in the WT rats (baseline: 103.5
+
1.85 to 89.9
+
3.06 mm Hg 24 hours) did not lower blood pressure in the KO at 24 hours (111.7
+
1.1 to 117.5
+
1.0 mm Hg) nor through 6 more days of infusion. Blood pressure reduction in the WT was accompanied with an elevation in heart rate (410
+
8 to 474
+
5 bpm; p<0.05) that was not observed in the 5-HT
7
receptor KO (387
+
10 to 395
+
4.3 bpm; p>0.05). Thus, pharmacological and molecular work powerfully support the necessity of the 5-HT
7
receptor for 5-HT-induced hypotension. The significance of this study capitalizes on the unique pharmacology of the 5HT
7
receptor and provides potential insight into the development of new treatment for CV diseases.
Abstract P341: Renal Denervation Prevents Cholinergic Mediated Hypertension and Renal Macrophage Infiltration
Authors: Raikwar Nandita , Ratcliff Jason , Allamargot Chantal , Chapleau Mark W , Abboud Francois M , Harwani Sailesh C
Published: March 2022

In vivo cholinergic activation with nicotine induces renal infiltration of M1 inflammatory CD161a+/CD68+ macrophages and the development of hypertension. Renal denervation has been proposed as a treatment for essential hypertension. Based on this we hypothesized that the renal sympathetic nerves play a role in these processes. Bilateral renal denervation was performed surgically in 3-4 week old Spontaneously Hypertensive Rats (SHR), a genetic model of essential hypertension. Following one week recovery, animals received subcutaneous infusion of nicotine (15mg/kg/day) via osmotic pumps for 2 weeks. Blood pressure was measured by tail-cuff and kidneys harvested on completion of infusion. Prior to nicotine infusion, at baseline, there was no difference between the systolic blood pressures of the sham treated (n=7) and renal denervation (n=10) groups, 132 ± 4 vs 128 ± 3 mmHg, respectively (p>0.05). In contrast, nicotine infusion significantly raised the systolic blood pressure in the sham treated group (159 ± 3mmHg), but not in the renal denervation group (135 ± 5 mmHg) (p<0.001). Moreover, nicotine infusion induced a significantly greater infiltration of inflammatory CD161a+ immune cells and CD161a+/CD68+ inflammatory macrophages into the renal medulla of the sham treated group (n=4) (13 ± 2 cells/hpf and 5 ±1 cells/hpf, respectively), compared to renal denervation(n=4) (2 ± 1 cells/hpf and 2 ± 1 cells/hpf) (p<0.001). We conclude that renal sympathetic innervation is required for the nicotine-induced migration of inflammatory CD161a+ immune cells and CD161a+/CD68+ inflammatory macrophages into the renal medulla and that renal denervation prevents the cholinergic-induced renal inflammation and hypertension in this model.
Abstract P346: Diurnal Variation of Serum Uric Acid Levels and Corresponding Variations of Oxidative Stress Makers in Patients With Hypertension and Stable Coronary Artery Disease
Authors: Shimizu Megumi , Kasai Takatoshi , Yatsu Shoichiro , Murata Azusa , Matsumoto Hiroki , Shitara Jun , Kato Takao , Suda Shoko , Hiki Masaru , Naito Ryo , Shimada Kazunori , Daida Hiroyuki
Published: March 2022

Background:
Hyperuricemia has been known as a risk factor of hypertension, stroke and coronary artery disease (CAD). Uric acid (UA) itself has antioxidative activity, but it is also reported that UA can also stimulate oxidative stress. In healthy subjects, it has been shown that UA has diurnal variation; elevate in the early morning. However, it is unclear whether such diurnal variation is observed and whether corresponding diurnal variation of oxidative stress can also be observed even in patients with CAD. Therefore, we investigated presence of diurnal variation of serum levels of UA, oxidative stress makers in patients with hypertension and CAD.

Method:
We measured serum levels of UA, NOx, and urinary levels of 8-OHdG, serum at 6 p.m., 6 a.m., 12 p.m. in 26 men with CAD. We excluded patients who was taking drugs which can affect UA levels.

Result:
Overall 20 patients were enrolled. Serum UA levels were 5.67±0.99 mg/dl at 6 p.m., 5.86±0.99 mg/dl at 6 a.m., and 5.73±0.99 mg/dl at 12 p.m., indicating obvious diurnal variation (P=0.0004). Serum UA levels increased significantly from 6 p.m. to 6 a.m. (P=0.002) and decreased significantly from 6 a.m. to 12 p.m. (P=0.002). Urinary level of 8-OHdG were 13.96±4.95 ng/mlCr at 6 p.m., 19.47±9.20 ng/mlCr at 6 a.m., and 16.19±5.52 ng/mlCr at 12 p.m., indicting corresponding diurnal variation to the serum UA level (P=0.013). Similarly, urinary levels of 8-OHdG increased significantly from 6 p.m. to 6 a.m. (P=0.008) and tend to decrease from 6 a.m. to 12 p.m. (P=0.57). Serum NOx levels were 13.19±6.60μM at 6 p.m., 12.11±6.02μM at 6 a.m. and 15.08±6.61μM at 12 p.m. and showed reciprocal diurnal variation to the serum UA and urinary 8-OHdG levels (p=0.0028).

Discussion:
Serum UA levels showed diurnal variation even in patients with hypertension and CAD. Considering the fact that oxidative stress makers showed corresponding diurnal variations, diurnal variation of serum UA level may play a role in the pathogenesis of CAD.
Abstract P356: Mmp-2/timp-2 Imbalance and Increased Collagen Production are Crucial to the Transition From Compensated Cardiac Hypertrophy to Heart Failure in Rats Subjected to Abdominal Aorta Constriction
Authors: Prado Cibele M , Pizzo Thayane R , Fernandes Aline , Amorin Vanessa A , Rizzi Elen , Meirelles Flavio V , Salgado Helio C
Published: March 2022

Background:
Hypertension causes cardiac hypertrophy, cardiac dysfunction, and heart failure (HF). The role of matrix metalloproteinases (MMPs) in the cardiac remodeling induced by hypertension has been demonstrated. Our objective was to evaluate whether temporal changes during the transition from compensated cardiac hypertrophy to HF may be dependent of MMP-2 activity in a model of pressure overload cardiac hypertrophy.

Methods:
Male Wistar rats were subjected to abdominal aorta constriction and observed after 30, 60, 90 days post surgery (dps). Systolic and diastolic cardiac functions were analyzed. Picrosirius red staining was used to quantify interstitial collagen in the left ventricle. Western blotting was performed for MMP-2 and tissue inhibitor of matrix metalloproteinase (TIMP)-2. Data were considered significant when p<0.05.

Results:
At 90 dps, 70% (28 of 40) presented hypertrophic hearts (HH) and 30% (12 of 40) hypertrophic+dilated hearts (HD). The ejection fraction (EF) and fractional shortening (FS) at 30, 60 and 90 dps in the HH group were not different from sham. In the HD group, a decrease of 45% in the EF (35.46±3.29%) and 41.5% in the FS (21.60±5.34%) was observed compared to sham (62.62±5.82%; 35.28±2.47%, respectively). In relation to diastolic parameters, the mitral E-wave velocity increased 47% (1279±127) and E/E’ ratio increased 60% (68.14±16.78) only in the HD group in relation to sham (866±134; 26.99±5.47, respectively). Increased interstitial collagen was observed at 30 (2.08±0.14%), 60 (2.48±0.29%) and 90 dps in the HH (2.83±0.18%) and HD groups (2.82±0.16%) when compared to sham (1.62±0.15%). There is no alteration in the MMP-2 expression at 30 and 60 dps. An increase of 54.4% in the HH group (1.22±0.23) and 51% in the HD (1.19±0.34) was observed in relation to sham (0.79±0.32). TIMP-2 expression increased 82% at 60 dps (1.30±0.17), 62% in the HH group (1.15±0.31) and 51% in the HD group (1.07±0.31) when compared to sham (0.71±1.12).

Conclusion:
The imbalance between MMP-2 and TIMP-2 expression associated with increased collagen content suggests that the deregulation of MMP-2 expression by TIMP-2 could contribute to the transition from compensated cardiac hypertrophy to heart failure.
Abstract P364: Altered Circadian Rhythm in Blood Pressure in Obstructive Sleep Apnea
Authors: Thosar Saurabh S , Butler Matthew P , Hu Kun , Scheer Frank A , Smales Carolina , DeYoung Pamela N , Hussain Mohammad , Morimoto Miki , Shea Steven A
Published: March 2022

Background:
In people with obstructive sleep apnea (OSA), adverse cardiovascular (CV) events occur most commonly during the night, about 6 hours earlier than the morning peak of events observed in the general population. In healthy individuals, circadian rhythms in many CV risk markers peak in the morning, around the common time of occurrence of adverse CV events. We therefore tested whether circadian rhythms are advanced in those with OSA, which might explain the earlier time of adverse CV events.

Methods:
Eleven volunteers (4 healthy controls and 7 OSA; 55 ± 5 years of age) completed a 5-day laboratory protocol with sleep and all other behaviors evenly spaced across the 24 h circadian period. To achieve this, after a baseline night, participants completed 10 consecutive short-day cycles of 2 h 40 min each of wakefulness and sleep opportunity. Blood pressure and heart rate were recorded 10 min after each wake time. Salivary melatonin and cortisol concentration were measured at 1-1.5h intervals during wakefulness. Cosinor analyses were performed to determine the rhythmicity of the all variables. We also compared OSA data with larger groups of historical healthy controls from our laboratory.

Results:
The circadian times of peak systolic and diastolic blood pressure were significantly advanced (up to 7 hours) in OSA as compared to healthy controls, p<0.05. Circadian peaks in all other measured variables were not different between OSA and controls.

Conclusions:
These results suggest that OSA is associated with a change in the timing of endogenous circadian blood pressure rhythms. This may be specific to the cardiovascular system as there was no evidence for altered phase of melatonin or cortisol secretion patterns. The relatively advanced blood pressure rhythms in OSA is similar to the advancement of the time of adverse CV events in OSA and should be further investigated.
Abstract P374: Smartphone Application for Blood Pressure Monitoring: Whitings vs MobileRapid (Pic S)
Authors: prati lucia , Pecchioli Valerio
Published: March 2022

HBPM has a limits: the poor compliance with the correct method and the compilation of the paper diary. Telemonitoring of arterial pressure - wants to overcome these predetermined limits. The goal of telemonitoring of the pressure is to improve the management of the hypertensive condition. Aim of our study: to evaluate the perception of qualitative parameters for the extensive use of blood pressure telemonitoring such as: Eases, clarity of the display, speed, noise, practicality and reliability, comparing two different oscillometric devices for blood pressure measurement with Bluetooth connectivity to a smartphone app with the ability to send the data press directly to its reference center : MobileRapid (A), Whitings (B).

Materials and Methods:
We have enrolled 60 hypertensive patients, 30 M and 30 F with an average age of 40.5± 9.74 y. All patients were asked to carry out the automated blood pressure with the two devices. Each patient was given a questionnaire that investigated the perception of subjective parameters by the patient of a device in comparison to the other (A vs C) and the patient’s orientation about the possibility of connecting the pressure measuring device to a specific app to send the data.

Results:
50 out of 60 pts (83.33%)of the sample perceived overall easier to use the device A against 9 out of 60 (15%) C (p <0.0001) 43 out 60 (71.67%) found it clearer (p <0.0001), 31 out of 60 (51.67%) faster (p = 0.0078), while for the silent parameter 25 out of 60 (41.67%) of patients preferred C and for 28 out of 60 (46.67%) there was no No difference (p = 0.0016). Device A appeared to be more practical in 45 out of 60 (75%) patients compared to 20% for Device C (12 pts out of 60) (p <0.0001), and in 46 out of 60 (76.67%) of cases worldwide, MobileRapid appeared more reliable than Whitings (p <0.0001).

98% of the sample (58 pts) is interested in having a dedicated app.

Conclusions:
The MobileRapid device is perceived reliable, faster than Whitings. The good thing is that our sample, albeit not numerically elevated, has shown almost total interest in being ’connected’ with your doctor as well as constantly monitoring your pressure values.
Abstract P388: Acute but Not Long-term Blood Pressure Lowering by Renal Denervation in Reduced Renal Mass, Salt Sensitive Hypertension
Authors: Tudorancea Ionut , Lohmeier Thomas E , Alexander Barbara T , Pieptu Dragos , Serban Dragomir , Iliescu Radu
Published: March 2022

Chronic kidney disease is prevalent among patients with resistant hypertension and activation of the sympathetic nervous system is common in both conditions. While renal nerve ablation lowers blood pressure (BP) in some resistant hypertensive patients, the influence of kidney disease on the antihypertensive response is largely unknown. Systemic hemodynamics and sympathetically-mediated low frequency oscillations of systolic BP were determined continuously by telemetry in rats before and after unilateral nephrectomy and surgical excision of the poles of the remaining kidney to reduce renal mass (RRM) ~ 80%. Before RRM, BP was not salt sensitive. However, placing rats with RRM on a high salt diet induced sustained increases in mean arterial pressure (Figure) and cardiac output while suppressing sympathetic activity. After denervation of the remnant kidney, sympathetic activity and heart rate increased, concomitant with reductions in BP and cardiac output. However, these acute responses waned over the 2 weeks of follow up. Subsequent central sympathetic inhibition with clonidine reduced sympathetic activity, heart rate and cardiac output, but not BP as peripheral resistance increased. Finally, when the low salt diet was restored, BP decreased back to normotensive levels. These results show that renal denervation does not chronically lower BP in this model of salt-sensitive hypertension associated with substantial nephron loss, but without active parenchymal disease, thus providing insight into conditions likely to impact the antihypertensive response to renal-specific sympathoinhibition in subjects with advanced kidney disease.
Abstract P390: Combining Olmesartan and Renal Denervation Elicits Strong Blood Pressure Reduction in Association With Sympatho-inhibitory and Aldosterone-reducing Effects in Hypertensive Mice With Chronic Kidney Disease
Authors: Nishihara Masaaki , Hirooka Yoshitaka
Published: March 2022

Background:
Augmented sympathetic nerve activity (SNA) and renin-angiotensin-aldosterone system (RAAS) are involved in the pathogenesis of hypertension (HT) accompanied with chronic kidney disease (CKD). The oxidative stress in the hypothalamus in the brain increases SNA in HT. The renal denervation (RDN) or angiotensin receptor blocker (olmesartan; OLM) exerts an antihypertensive effect in HT with CKD; however, the precise mechanisms of the combination therapy are not fully elucidated. In the present study, we examined whether combining RDN and OLM reduces SNA through oxidative stress in the hypothalamus and RAAS in hypertensive mice with CKD.

Methods and Results:
In 5/6-nephrectomized ICR-mice (Nx, n=19) at 4-weeks after nephrectomy, systolic blood pressure (SBP) was significantly increased (147±3 vs. 107±3mmHg, p<0.001), accompanied by increased SNA (urinary norepinephrine (uNE): 504±21 vs. 243±25μg/24hrs, p<0.001) and albuminuria (547±80 vs. 108±15mg/g creatinine, p<0.01) compared with those in control-mice (n=9). Nx-mice were orally-administered OLM (10mg/kg/day), vehicle, or performed RDN under OLM-administration, and divided into Nx-OLM (n=5), Nx-VEH (n=9), and Nx-OLM/RDN (n=5), respectively. In Nx-OLM and -OLM/RDN at 8-weeks after therapy, SBP were significantly decreased (124±3 and 116±3 vs. 144±2mmHg, n=5-9, p<0.05) accompanied with inhibition of both uNE (379±69 and 347±61 vs. 568±24μg/day, n=5-9, p<0.05) and oxidative stress in the hypothalamus (thiobarbituric acid-reactive substances: 0.952±0.06 and 1.012±0.041 vs. 1.222±0.047nmol/mg protein, n=5-9, p<0.05) compared with those in Nx-VEH, without worsening creatinine clearance. In Nx-OLM and -OLM/RDN, the albuminuria was also suppressed compared with that in Nx-VEH (476±56 and 499±82 vs. 1059±165mg/g creatinine, n=5-9, p<0.05). In Nx-OLM/RDN, but not in Nx-OLM, the plasma aldosterone concentration level was significantly decreased compared with that in Nx-VEH (441±35 vs. 675±33pg/ml, n=5-9, p<0.05).

Conclusion:
These findings suggest that the OLM/RDN combination therapy have a strong antihypertensive effect associated with inhibiting SNA through reducing oxidative stress in the brain and the plasma aldosterone in hypertensive mice with CKD.
Abstract P394: Reduced Serum Butyrate Is Associated With Dampened Central Effects Of Butyrate On Blood Pressure In The Shr
Authors: YANG Tao , Magee Kacy , Arocha Rebeca , Vickroy Thomas , Zubcevic Jasenka
Published: March 2022

Introduction:
The link between gut dysbiosis and hypertension is characterized by a significant reduction in butyrate-producing bacteria in the spontaneously hypertensive rat (SHR) compared with its Wistar Kyoto (WKY) control. Butyrate, a major end-product of gut microbiota fermentation, has beneficial effects in multiple dysbiosis-related diseases. Here, we investigated the link between serum butyrate levels and central effects of butyrate in regulation of blood pressure (BP) in WKY and SHR.

Methods:
Serum samples were collected from 12 weeks old male WKY and SHR, and butyrate quantification was performed using LC-MS. Quantitative real time PCR was employed to measure relative expression levels of butyrate sensing receptors (Gpr41, Gpr43) in the hypothalamus of SHR and WKY. Central effects of butyrate on BP were evaluated by acute ICV injection in anaesthetized WKY and SHR.

Results:
Significantly lower levels of serum butyrate were observed in the SHR (WKY 1.23±0.14μmol/L vs SHR 0.23±0.033μmol/L, N=4, P=0.0005). Moreover, lower expression of Gpr43 were observed in the hypothalamus of SHR (WKY 0.0002 ± 2.7e-005 vs SHR 6.9e-005 ± 1.9e-005, N=4/3, P=0.0152). ICV administration of butyrate reduced BP in both strains; however, the reduction in arterial BP was greater in the WKY at two time points (400s post-injection: WKY -5.83±0.49mmHg vs SHR -2.62±0.63mmHg, N=4, P=0.0235; 1000s post-injection: WKY -19.7±1.85mmHg vs SHR -13.26±1.1mmHg, N=3, P=0.05).

Conclusion:
Reduced serum butyrate is associated with reduced sensitivity to central butyrate. This may contribute to elevation in BP in the SHR.