bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 212: Effect of a High-fat Diet on Endothelial Function in Pregnant Rats
Authors: Spradley Frank T , Palei Ana T , Ryan Michael J , Granger Joey P
Published: March 2022

During preeclampsia (PE), placental ischemia increases plasma levels of soluble placental factors that promote endothelial dysfunction. Reports indicate that metabolic factors may also play a role in the pathogenesis of PE. While previous studies have shown that high-fat diet (HFD) results in endothelial dysfunction in normal animals, the effect of HFD on endothelial function during pregnancy is unclear. The purpose of this study was to determine the effects of HFD on endothelial function in pregnant rats. Twelve week old sprague-dawley rats were fed a normal diet (ND; 13% fat kcal; N=5-8) or HFD (40% fat kcal; N=9-11). After 9 weeks, body weight was greater in HFD: 294 ± 5 g v. ND: 272 ± 6 g (p<0.05) whereas caloric intake was similar (kcal/wk: ND: 347 ± 18 v. HFD: 393 ± 9). At 10 weeks, timed-pregnant rats were generated. At gestational day 19, body weight was not statistically different in ND: 377 ± 7 g and HFD: 394 ± 9 g . Visceral fat mass (combined dorsal, uterine, bladder fat) was similar in ND: 10.6 ± 0.8 g and HFD: 13.1 ± 0.9 g and brown fat (interscapular) fat mass was similar in ND: 0.9 ± 0.1 g and HFD: 0.8 ± 0.1 g. Plasma triglyceride levels were similar (mg/dL: ND: 23 ± 7 v. HFD: 38 ± 6). Mean arterial blood pressure assessed via left carotid arterial catheters was similar (mmHg: ND: 112 ± 7 vs. HFD: 108 ± 3). Wire myography showed that endothelial-dependent relaxation to acetylcholine in right carotid arteries was similar (maximum % relaxation: ND: 93 ± 3 vs. HFD: 88 ± 4; logEC50 sensitivity: ND: -6.8 ± 0.2 vs. HFD: -6.4 vs. 0.2). Endothelial-independent vasorelaxation to Na nitroprusside was similar (maximum % relaxation: ND: 103 ± 3 vs. HFD: 101 ± 1; logEC50 sensitivity: ND: -8.4 ± 1 vs. HFD: -8.6 ± 0.1). Endothelial denudation augmented constriction to phenylephrine similarly in ND (maximum % of 100mM KCl: + endothelium: 46 ± 4 v. - endothelium: 91 ± 16; p<0.05) and HFD (maximum % of 100mM KCl: + endothelium: 57 ± 6 v. - endothelium: 98 ± 10; p<0.05) and the + endothelium responses were similar in both groups. Plasma nitrite to assess bioavailable NO was similar (μM: ND: 38 ± 6 and HFD: 52 ± 10). These data suggest that normal pregnancy protects against HFD-induced endothelial dysfunction. Loss of this protective effect in response to placental soluble factors could lead to hypertension in PE.
Abstract 218: TRPM7 Kinase - A Novel Signaling Pathway for Ang II-induced MAPK Activation in Vascular Smooth Muscle Cells.
Authors: Antunes Tayze T , Yogi Alvaro , He Ying , Callera Glaucia E , Montezano Augusto C , Ryazanov Alexey G , Ryazanova Lillia V , Touyz Rhian M
Published: March 2022

Transient receptor potential melastatin 7 (TRPM7) cation channel is a unique protein, which regulates transmembrane magnesium (Mg2+) transport through its channel domain, and intracellular signaling through its kinase domain. We previously demonstrated that TRPM7, is expressed on vascular smooth muscle cells (VSMC), controls Mg2+ influx, and is regulated by angiotensin II (Ang II). Low Mg2+ levels are among the many factors leading to hypertension, where intracellular Mg2+ deficiency and TRPM7 downregulation is observed. Despite the advancement in the understanding of Mg2+ and TRPM7 biology, the role of TRPM7, and its kinase, in hypertension remains elusive. In this study, we investigated whether deletion of TRPM7 kinase domain alters Ang II-induced Mg2+ influx and signaling in VSMCs. Cultured VSMCs from mesenteric arteries obtained from heterozygous mice for the TRPM7 kinase deletion (+/-) and WT mice were used. Mg2+ influx was assessed by fluorescence microscopy. Activation of MAP kinases was evaluated by immunoblotting. Ang II (10-7M) increase in Mg2+ influx was similar in VSMC from both, WT and TRPM7+/- mice (2.5-fold; p<0.001). Ang II increased phosphorylation of JNK (10-fold), p38MAPK (4-fold) and ERK1/2 (6.4-fold) in VSMC from WT mice (p<0.001). Ang II-induced MAPK activation was blunted in TRPM7+/- VSMC. Moreover, Ang II treatment induced PDGF-R (2-fold) and Akt phosphorylation (3-fold) in VSMC from WT mice (p<0.05), an effect that was also blunted in TRPM+/- VSMC. Ang II induced SMAD2/3 activation in VSMC from WT (1.5-fold; p<0.05) and, with a greater extent, TRPM7+/- mice (3.5-fold; p<0.05). To understand whether the blunted effects of Ang II on intracellular signaling in VSMC from TRPM7+/- mice could be attributed to downregulation of Ang II receptors, AT1R and AT2R expression was assessed. No differences in receptor expression were observed between VSMC from WT and TRPM+/-. In conclusion, our findings identify that TRPM7 kinase domain is not necessary for Mg2+ influx, but it seems to be a novel and important player in Ang II-induced signaling in VSMCs.
Abstract 230: AT2 Receptor Agonist, Compound 21, Attenuates Pulmonary Hypertension and Associated Cardiac Pathophysiology via the Vasoprotective ACE2/Ang-(1-7)/Mas axis
Authors: Bruce Erin , Shenoy Vinayak , Francis Joseph , Steckelings U. Muscha , Unger Thomas , Sumners Colin , Raizada Mohan K , Katovich Michael J
Published: March 2022

Pulmonary hypertension (PH) is a devastating disease affecting the lung vasculature. Recently, we determined that increased activation of the ACE2/Ang-(1-7)/Mas axis attenuates much of the associated pathophysiology. In other models of cardiovascular disease, the beneficial effects seen with ACE2/Ang-(1-7)/Mas activation are similar to those seen by AT2 receptor (AT2R) activation. We hypothesize that activation of the AT2R, via selective agonist Compound 21 (C21), will be an effective treatment against PH. SD rats were injected with 50mg/kg of monocrotaline (MCT) at 8 weeks of age, to induce PH. Control animals were given saline. Two weeks post MCT injection, when right ventricular systolic pressures (RVSP) were significantly elevated (MCT 48.3±8.8; Control 32.0 ±2.4 mmHg), animals received 0.03mg/kg/day C21 ip (MCT+C21) or vehicle for 2 weeks. Two weeks later, RV hemodynamic parameters were measured and tissues collected. Treatment with C21 significantly reduced PH and associated cardiac pathophysiologies. The mechanism by which C21 attenuates PH may be the restored balance between the RAS vasodeleterious and vasoprotective arms. Relative quantitation of lung mRNA expression showed C21 treatment normalized the ACE/ACE2 and AT1R/AT2R ratios, and increased Mas receptors. C21 also attenuated the increase in pro-inflammatory cytokines TGF-β, TNF-α, and Il-1b. The increased expression of the vasoprotective axis and resulting decrease in inflammatory cytokines may account for reduced PH and associated cardiopathophysiology. The increases in ACE2/Mas receptor expression may indicate an underlying connection between the AT2R and the vasoprotective axis of the RAS.
Abstract 245: Synergistic Effects of Nicotine and Angiotensin II: Implications for Progression of Chronic Kidney Disease in Smokers
Authors: Ryder Charity Y , Hua Ping , Feng Stanley , Chunley Phillip , Renozwez Gabriel , Jaimes Edgar A
Published: March 2022

Increased generation of Angiotensin II (ANG II) plays a key role in the progression of chronic kidney disease (CKD). Cigarette smoking accelerates the progression of CKD of different etiologies including hypertension and diabetes. We have shown that nicotine (NIC), a biologically active compound present in large amounts in tobacco, worsens the severity of injury in experimental models of CKD. The aim of this study is to determine whether NIC and ANG II have synergistic effects on fibronectin production and proliferation in mesangial cells (MC). Rat MC were exposed to different concentrations of NIC (10
-4
M to 10
-10
M) and/or ANG II (10
-6
M to 10
-10
M) for 24 hours. Fibronectin production was measured by western blot and proliferation by EdU incorporation. As shown in Table 1, NIC and ANG II have synergistic effects on the production of fibronectin in MC.

Shown in Table 2, NIC and ANG II have additive effects on MC proliferation.

These synergistic effects of NIC and ANG II may explain the deleterious effects of smoking in conditions associated with increased activation of the renin angiotensin system.
Abstract 26: CD4+T Cells Play a Critical Role in Mediating Hypertension in Response to Placental Ischemia
Authors: LaMarca Babbette , Novotny Sarah , Wallace Kedra , Moseley Janae , Darby Marie , Heath Judith , Martin James N
Published: March 2022

Similar to preeclamptic women, hypertension in the chronic reduced uterine perfusion pressure rat model of preeclampsia (RUPP) is associated with increased CD4+ T cell activation, cytokines, sFlt-1 and agonistic autoantibodies to the AngII receptor (AT1-AA). Although we have shown that adoptive transfer of RUPP CD4+ Tcells into normal pregnant (NP) recipients rats causes hypertension and the release of above mentioned factors, the role of endogenous CD4+T cells in mediating the pathophysiology of preeclampsia was unknown. Therefore, we tested the hypothesis that activation of CD4+ T cells causes hypertension and increased sFlt-1, TNF-alpha and AT1-AA. We first examined the effect CD4+ T cell blockade in NP and RUPP rats treated with Orencia, (abatecept, 250mg/kg, infused iv at gestation day 13), clinically used to inhibit T cell activation. RUPP surgical procedure was performed on day 14. On day 19 MAP increased from 94+/-2 mmHg in NP to 123+/-3 mmHg in RUPP control rats. This response was attenuated by CD4+ Tcell blockade, MAP was 104+/-2 mmHg in Orencia treated RUPPs, and 96 +/-2 mmHg Orencia treated NPs. Circulating CD4+ T cells were 66+/-3 in RUPPs compared to 55+/-3 NP rats (p<0.04) but were normalized in Orencia treated RUPP rats (54+/-3). The twofold increase in TNF alpha seen in RUPPs (277+/-47 pg/ml) was decreased to 80 +/-18 pg/ml in Orencia treated RUPPs. Placental sFlt-1 was reduced 70 % to 151+/-28 in Orencia treated RUPP compared 488+/-61 pg/ml in RUPP (P<0.001). AT1-AA decreased from 20+/-0.8 bpm in control RUPP to 6+/-0.7 bpm in Orencia treated RUPPs. We next determined the effect of RUPP in causing hypertension in pregnant T cell deficient rats by examining MAP in NP (121 mmHg) and RUPP athymic nude rats (126 mmHg). In the absence of T cells, hypertension in response to placental ischemia was completely abolished. Collectively these data indicate that activation of CD4+ Tcells in response to placental ischemia plays an important role in the pathophysiology of hypertension associated with preeclampsia.
Abstract 263: 20-hete-induced Vascular Remodeling in Models Of Androgen-dependent and Independent Hypertension
Authors: Ding Yan , Wu Cheng-Chia , Garcia Victor , Dimitrova Irina , Weidenhammer Adam , Zhang Frank , Falck John R , Mei Shaojun , Capdevila Jorge , Schwartzman Michal L
Published: March 2022

20-Hydroxyeicosatetraenoic acid (20-HETE) promotes smooth muscle contraction and proliferation, endothelial dysfunction and activation and hypertension. We have previously demonstrated that 20-HETE mediates androgen-induced hypertension. This study examines if 20-HETE contributes to vascular remodeling in androgen-induced hypertension. Sprague-Dawley rats were treated with vehicle or 5α-dihydrotestosterone (DHT) with and without the 20-HETE synthesis inhibitor (HET0016, 10mg/kg/day) for 14 days. Media-to-lumen ratio (M:L) in renal interlobar arteries from DHT-treated rats was higher (P<0.05) than vehicle-treated rats (0.21±0.01 vs. 0.15±0.02). This was prevented by HET0016 (0.14±0.01). Arteries from DHT-treated rats had increased (p<0.05) collagen type IV that was attenuated by HET0016. To assess whether 20-HETE induces vascular remodeling independent of blood pressure (BP) increase, reserpine (100 μg/kg/day) was administered to DHT- and vehicle-treated rats for 21 days. DHT increased BP (133.7±2.4 vs. 101.40±0.40 mmHg). Reserpine prevented this BP increase (104.20±1.30 mmHg) but had no effect on DHT-induced increase in M:L ratio (0.19±0.02) or in collagen I/IV deposition. These results suggest that DHT-mediated vascular remodeling is 20-HETE-dependent and that 20-HETE may contribute to DHT-induced vascular remodeling independent of BP elevation. Whether 20-HETE induces vascular remodeling in a DHT-independent manner was also examined. Cyp4a12 transgenic mice were treated with doxycycline (DOX) for 42 days to upregulate the cyp4a12 expression. BP of DOX-treated cyp4a12tg mice significantly increased compared to vehicle (139.59±4.06 vs. 92.25±5.25 mmHg) and 20-6,15-HEDE abolished BP increase (88.63±1.13 mmHg). Media thickness and M:L ratio significantly increased in DOX-treated group compared to vehicle (23.40±1.15 vs. 16.25±0.83μm; 0.39±0.04 vs. 0.23±0.02) and decreased by co-treatment with 20-6,15-HEDE (18.42±1.53μm; 0.28±0.03). These results indicate that 20-HETE can induce vascular remodeling in the absence of androgen.
Abstract 264: Erythropoietin-induced Hypertension and Vascular Injury in Mice Overexpressing Human Endothelin-1 Was Attenuated by Exercise
Authors: Barhoumi Tlili , Briet Marie , Paradis Pierre , Laurant Pascal , Schiffrin Ernesto L
Published: March 2022

Background:
Erythropoietin (EPO) is used to correct anemia in chronic kidney disease (CKD). EPO has been shown to increase blood pressure (BP) in patients and animals with CKD. This BP rise can be blunted by endothelin (ET) A receptor blockers. Chronic exercise prevents or reduces development of cardiovascular disease. However, it is unknown whether exercise prevents EPO-induced hypertension. We hypothesized that EPO treatment would exacerbate endothelin (ET)-1-induced vascular damage and increase BP, and that exercise training might prevent these effects.

Methods:
Eight to 10-week old male mice overexpressing human preproET-1 in the endothelium (eET-1) were treated with EPO (100 U/kg, s.c, 3 times/week) or not, and subjected to swimming exercise (1 h/d, 5 d/week) for 8 weeks or maintained in sedentary condition (n=7-8). Wild-type (WT) mice were also treated or not with EPO. Systolic BP (SBP) was measured by the tail-cuff method. Endothelial function was assessed in mesenteric arteries by pressurized myography. NADPH oxidase activity was assessed in aorta or renal cortex of by lucigenin chemiluminescence, reactive oxygen species (ROS) by dihydroethidium staining, and monocyte/macrophage and T regulatory cell (FoxP3) infiltration, and VCAM-1 by immunofluorescence staining.

Results:
EPO increased SBP by 24 mmHg (
P
<0.05) and impaired vasodilatory responses to acetylcholine in eET-1 (68% vs. 91%,
P
<0.01). NADPH oxidase activity was 2-fold higher in eET-1 than in WT (
P
<0.05), and further increased 1.5-fold by EPO (
P
<0.01). ROS production in aorta of WT was enhanced 2-fold (
P
<0.01) by EPO, which increased ROS in eET-1 a further 9-fold (
P
<0.01). EPO increased monocyte/macrophage infiltration in aorta of WT 2.5-fold (
P
<0.01), and in eET-1 a further 2.7-fold (
P
<0.05). VCAM-1 expression in aorta was 2.7-fold higher in eET-1 than in WT (
P
<0.05). All of the above was prevented by exercise (
P
<0.05). Exercise with or without EPO increased T regulatory FoxP3
+
lymphocytes in renal cortex 3-fold compared to eET-1 and WT (
P
<0.01).

Conclusions:
Exercise prevents EPO-induced BP elevation and vascular damage through a mechanism involving decreased vascular oxidative stress and inflammation.
Abstract 270: Arginase I Deletion Blocks Age-Related Enhancement of Vascular Stiffness and Endothelial Dysfunction
Authors: Toque Haroldo A , Nunes Kenia P , yao Lin , Bhatta Anil , Anea Ciprian B , Rudic R. D , Webb R. C , Caldwell Ruth B , Caldwell R. W
Published: March 2022

Vascular stiffening, decreased nitric oxide (NO) bioavailability and vascular endothelial dysfunction (ED) are markers of the aging cardiovascular system. Increased vascular stiffness and ED are predictors for adverse cardiovascular outcomes. Increased vascular arginase activity has been noted to accompany aging-induced endothelial dysfunction (ED). Therefore, we hypothesized that enhanced arginase activity is involved in age-related increases in arterial stiffness and ED and that limiting the activity of arginase I (Arg I) would reduce this pathology. We tested this hypothesis by analysis of vascular stiffness and ED in aortas from old (12-month) and young (3-month) male wild type (WT) mice and mice lacking one copy of arginase I (Arg I
+/-
KO).
In vivo
studies measured vascular stiffness by pulse wave velocity (PWV) and systolic blood pressure (SBP) by tail cuff. Vascular endothelial function studies also were performed
ex vivo
using myography. Arginase activity assay showed that activity in the aged WT mice was 1.47-fold greater than that in the young WT mice. PWV was markedly increased in old WT mice (1.96±0.28 m/s) compared to young WT mice (1.08±0.10 m/s). By contrast, PWV remained normal in old Arg I
+/-
KO mice (1.15±0.08 m/s). Endothelium (NO)-dependent vasorelaxation to acetylcholine (ACh) was significantly reduced in the old WT mice as compared with young WT mice (maximum relaxation (MR) of 60±3%
vs
78±4%, respectively). This age-induced impairment was markedly blunted in aged Arg I
+/-
KO mice (MR: 71±3%). The arginase inhibitor BEC (100 μM) also reversed the impairment in ACh-induced vasorelaxation in old WT mice (P<0.05). No differences were observed in endothelial-independent relaxation to SNP among the groups. SBP was also unchanged. In conclusion, deletion of one copy of Arg I prevents ED and reduces vascular stiffness in aging. Thus, reduction of arginase I function may serve as a therapeutic target for normalizing arterial stiffness and preventing vascular dysfunction in aging.
Abstract 272: Vascular Reactivity During Insulin Infusion and Oral Glucose Challenge
Authors: Puzantian Houry , Mosenkis Ari , Townsend Raymond R
Published: March 2022

Vascular rigidity predicts cardiovascular disease (CVD). Pulse wave velocity (PWV), reflecting vascular rigidity, though determined largely by mean arterial pressure; is also sensitive to insulin and glucose. Capacitance in small (C2) and large vessels (C1), reflecting vascular responsiveness to hemodynamic challenges, may also be influenced by insulin and glucose. The purpose of this study was to test the effects of insulin and glucose on arterial function in healthy people.

METHODS:
Excluding people with BMI > 27.5 kg/m2, diabetes, impaired glucose tolerance, hypotension or hypertension, 14 adults were enrolled. Subjects underwent randomly either a 2 hour euglycemic clamping, or a 2-hr OGTT first, and the other a month later. Pulse wave velocity (PWV; carotid->dorsalis) and vascular compliance were measured by tonometry. Repeated measures ANOVA was used to compare parameter means over different time points.

Results:
The sample (n=14) included 10 Caucasians, 8males, mean age=28.14+7.6 years, BMI=23.46+1.7kg/m2, SBP=112.79+8.6mmHg, DBP=69.57+6.1mmHg, and glucose=73+10.5mg/dl. There was a significant increase in mean PWV between 30 and 120 minutes (p=0.049), by euglycemic clamp (PWV change in OGTT was n.s.).

Conclusion:
Insulin increased the PWV in clamp condition with minimal changes in C1 or C2. Oral glucose had less effect on PWV and again changes in C1 and C2 were minimal. These data support mechanisms that interweave insulin and arterial stiffness in vascular physiology and suggest that part of the mechanism of CVD in insulin resistance may relate to insulin’s effects on arterial rigidity.
Abstract 28: Increased Blood Pressure Response to Salt Intake in Hypertensive G Carriers of The NEDD4L SNP rs4149601
Authors: Nicolas Hannah A , Kulik Rafal , Lamothe Gilles , Bolongo Pierrette M , McRae Karalyn , Kingsbury Chelsea , Stewart Alexandre F , Leenen Frans , Tesson Frederique
Published: March 2022

Introduction:
Individual blood pressure (BP) response to high salt intake varies from minimal to substantial and is largely genetically determined. More than 50% of hypertensive patients are salt sensitive (SS) and respond to high salt intake by increasing their BP compared to only 10% in the normotensive population. ENaC is involved in sodium transport in the distal nephrons of the kidney as well as in the CNS in the choroid plexus and hypothalamic neurons. In turn, ENaC is controlled by the E3 ubiquitin ligase protein - NEDD4L. The functional NEDD4L SNP rs4149601 (G/A) influences the ability of NEDD4L to regulate ENaC expression and is associated with high blood pressure and salt sensitivity. We hypothesize that NEDD4L rs4149601 genotype is an independent predictor of BP response to salt intake in hypertensives.

Methods:
Daytime BP was measured using 24hr ABPM in 191 young (<60 years old) Caucasian hypertensives (BP ≥130/85 mmHg). 24hr urine Na and K
+
, blood Na
+
and K
+
, and BMI were collected. Patient genotyping for the rs4149601 (G/A) SNP was done using TaqMan MGB probe based RT PCR. Linear regression analyzed (SAS Software) the influence of urine Na
+
, urine K
+
, blood K
+
,blood Na
+
, age, gender, and BMI on blood pressure traits.

Results:
In hypertensive rs4149601 G carriers (n=169), systolic BP (SBP) varied significantly with salt intake (p=0.0088) while diastolic BP did not (p=0.7198). An SBP increase of 2.34 mmHg per 50 mmol Na was observed when urine Na alone is considered. Age (p=0.0002) and blood K
+
(p=0.0466) were also significant determinants of SBP in patients with the G allele. Only blood K
+
was a significant predictor of diastolic BP (DBP) in hypertensive G allele carriers. None of the factors tested influenced either SBP or DBP in hypertensive patients who are carriers of the A allele.

Conclusion:
The functional NEDD4L rs4149601 SNP influences individual daytime BP response to salt intake. This result supports the hypothesis that NEDD4L rs4149601 G carriers with intact C2 domain express higher levels of ENaC and therefore are more sensitive to salt intake. Thus, NEDD4L rs4149601 polymorphism genotyping may allow for identification of hypertensive individuals who will benefit to a greater extent from reducing the amount of salt in their diet.
Abstract 283: Predominance of Angiotensin II Type 1 Receptor Blockade Over Angiotensin-(1-7) Mechanisms in the Regulation of Blood Pressure and Renin Angiotensin System in mRen.Lewis Rats
Authors: Varagic Jasmina , Ahmad Sarfaraz , Moniwa Norihito , Brosnihan K. Bridget , Wysocki Jan , Batlle Daniel , Ferrario Carlos M
Published: March 2022

We investigated the angiotensin-(1-7) [Ang-(1-7)] mediated effects of Ang II receptor (AT
1
-R) blocker -olmesartan medoxomil-on blood pressure, plasma, renal, and cardiac Ang II as well as activities of the enzymes involved in peptide formation or metabolism in mRen2.Lewis congenic hypertensive rats, a model of Ang II tissue-dependent hypertension. mRen2.Lewis rats were treated with either vehicle (n=14) or olmesartan (0.5 mg/kg/day; n=14) by osmotic minipumps. After 2 weeks rats from both groups were further randomized to receive either the mas receptor antagonist A-779 (0.5 mg/kg/day; n=7 per group) or its vehicle (n=7 per group) for the next 4 weeks. Antihypertensive effect of olmesartan monitored by telemetry (Figure) was associated with an increase in plasma renin concentration (PRC), plasma Ang II (513 ± 115 vs. 31 ± 5 fmol/mL; p<0.05) and Ang-(1-7) (60 ± 5 vs. 27 ± 4 fmol/mL; p<0.05) while reduced kidney Ang II content and no changes in kidney Ang-(1-7), angiotensin converting enzyme (ACE), ACE2 and neprilysin activities were noted in olmesartan treated group when compared to the controls (Figure). Olmesartan had no effect on cardiac peptide levels
.
Concomitant administration of A-779 increased PRC but had no effect on blood pressure or other RAS components. Our study highlights the independent regulation of RAS among plasma, heart, and kidney tissue in response to AT
1
-R blockade. Ang-(1-7) through mas-receptor does not mediate long-term effects of olmesartan besides counterbalancing renal renin release in response to AT
1
-R blockade.
Abstract 294: Intra-renal Administration of Hepatocyte-Growth Factor Reversed Microvascular Functional Rarefaction and Decreased Remodeling in the Stenotic Kidney
Authors: Chade Alejandro
Published: March 2022

Background:
We have shown that renal microvascular (MV) damage and loss contributes to the progression of renal injury in the stenotic kidney (StK). Hepatocyte growth factor (HGF) is a powerful angiogenic and anti-fibrotic cytokine that we have shown to be reduced in the StK. Thus, we hypothesize that intra-renal administration of HGF will protect the renal MV architecture and function in the StK.

Methods:
Renal artery stenosis (RAS) was induced in 10 pigs. Pigs were observed untreated for 6 weeks and then RBF and GFR quantified
in vivo
using multi-detector CT. Then, rh-HGF (RAS+HGF, 2 ug/kg, single injection, n=5) or placebo (n=5) was infused in the StK, observed for 4 additional weeks, and
in vivo
CT studies repeated. Pigs were then euthanized at 10 weeks, StK removed, renal MV architecture quantified using 3D micro-CT
in situ
, and renal angiogenic activity, MV remodeling, and fibrosis was determined
ex vivo
.

Results:
Intra-renal administration of HGF improved RBF and GFR at 10 weeks, accompanied by improved angiogenic signaling, decreased MV remodeling and fibrosis. However, renal MV density not altered by treatment with HGF. (Figure).

Conclusion:
Despite a similar MV density, an intra-renal administration of HGF improved renal hemodynamics, decreased MV dysfunction and remodeling, and attenuated fibrosis, suggesting a protective effect of rh-HGF in the StK. These results indicate that, in the stenotic kidney, HGF has the potential to improve renal function by protecting the renal microvasculature.
Abstract 295: The Role of 20-HETE in the Control of Prostate Cancer Tumor Vasculature
Authors: Liu Yunmeng , Wu Cheng-Chia , Zhang Frank Fan , Falck John R , Schwartzman Michal
Published: March 2022

20-Hydroxyeicosatetraenoic acid (20-HETE) is a cytochrome P450-derived arachidonic acid metabolite endowed with vasoconstrictor. Recent reports documented that 20-HETE synthesis inhibitors decrease the growth of glioma and renal cell carcimona, and that urinary 20-HETE levels are significantly elevated in prostate cancer patients. These reports led us to investigate the role of 20-HETE in the regulation of blood flow to prostate cancer tumors. First, we compared 20-HETE levels in prostate cancer cell line-LNCaP and normal prostate epithelial cells. Cultured LNCaP cells produced high levels of 20-HETE (566±139 pg/mg protein), whereas 20-HETE production was undetectable in normal prostate epithelial cells. Second, subcutaneous tumors were induced in balb/c nude mice by injection of LNCaP cells, followed by assessment of 20-HETE in both tumors and isolated tumor vessels. We found that LNCaP cell-derived tumors had high levels of 20-HETE (425±97 pg/mg protein), while the level in isolated tumor vessels was undetectable. Third, we used laser-doppler flowmetry to evaluate whether tumor-derived 20-HETE influences tumor blood flow and vessel diameter in vivo. Topical application of the 20-HETE antagonist 20-6,15-HEDE (1 mM) to tumor vessels in vivo increased blood flow by 1.81±0.34-fold and vessel diameter by 1.286±0.133-fold, which responses were reversed by topical application of 20-HETE in a dose-dependent manner. We conclude that LNCaP cell-derived tumors produce 20-HETE which, in turn, promotes vasoconstriction leading to reduction of tumor blood flow.
Abstract 304: Elevated Supine Arterial Pressure in Children with Postural Orthostatic Tachycardia
Authors: Fortunato John E , Shaltout Hossam A , Diz Debra I
Published: March 2022

Elevated supine mean arterial pressure (MAP) is often present in adults with dysautonomia. Children 15.1 ± 0.4 yrs of age (n = 22) with chronic unexplained nausea underwent continuous measures of supine blood pressure (BP) and heart rate (HR) pre- and post-tilt (0-70 degrees upright) and spectral analysis of their autonomic profile. Diagnostic workup revealed ∼77% have postural orthostatic tachycardia syndrome (POTS). The controls in this cohort had chronic nausea but were identified as normal upon tilt. Resting supine MAP and HR prior to tilt were higher in POTS subjects compared with controls, while most indices of autonomic function were similar (Table 1). Those diagnosed with POTS maintained MAP during tilt accompanied by a >5-fold increase in cardiac sympathetic drive (LFrri/HFrri) and >80% suppression of the baroreceptor reflex sensitivity (high frequency alpha index;HFα) in comparison to 2-fold and ∼60% responses in controls. BP variability (SDMAP) measured as the standard deviation of mean arterial presuure and HRV measured as the root of mean square of successive differences (rMSSD) were impaired to a greater extent in the POTS subjects. Exaggerated suppression of HRV during upright posture in POTS subjects is known. However, our studies reveal elevated supine MAP even at this young age. In adults, both impaired HRV and elevated supine MAP are risk factors for cardiovascular problems such hypertension and cardiac hypertrophy. Future studies are necessary to determine whether young adults with POTS are at greater risk of early onset cardiovascular disease, especially given the the potential impact of treatments aimed at increasing MAP. Support: AHA12CRP9420029
Abstract 312: Activation of GPR30 Attenuates Cardiac Injury in the Ovariectomized Diabetic mRen2.Lewis Rat
Authors: Santiago Nivia M , Figueiredo Gilberto Z , Souza Marina , Campagnole-Santos Maria J , Varagic Jasmina
Published: March 2022

Our previous study demonstrated that the exacerbation of hypertension as well as alterations in the angiotensin II type 1 receptor (AT1) and endothelial nitric oxide synthase (eNOS) pathways were associated with the development of cardiac remodeling in the diabetic, ovariectomized (OVX-D) mRen2.Lewis rats. The present study evaluated the cardiovascular effects of G-1, a selective agonist of the estrogen receptor GPR30, in insulin- and estrogen-depleted mRen.Lewis rats. Hemizygous littermates were divided into 3 groups: intact controls (C); OVX-D, and OVX-D treated with G1 (G-1). Ovariectomy was performed at 10 weeks of age and diabetes subsequently induced at 11 weeks with streptozotocin (65 mg/kg). G-1 was given by osmotic minipump implanted 2 days after STZ injection (0.2 mg/kg/day; ip). After four weeks blood pressure was measured and heart removed for analysis of AT1 receptor and eNOS protein expression as well as immunohistochemical identification of GPR30. Left ventricle (LV) wet weight was measured and cardiac tissue fibrosis was analyzed from the LV sections stained with picrosirius red. Immunohistochemical staining for GPR30 was evident in both coronary vessels and cardiac myocyte of the OVX-D rats. Chronic treatment with G1 decreased the systolic blood pressure (C: 142 ± 3; OVX-D: 184 ± 3*; G-1: 167 ± 6*
#
mmHg; *p<0.05 vs C;
#
p<0.05 vs OVX-D) and the incidence of microinfractions but did not reduce LV weight of OVX-D mRen2.Lewis rats (C: 0.57 ± 0.01; OVX-D: 0.62 ± 0.02*; G-1: 0.63 ± 0.01*g). G-1 treatment was associated with an increase in the cardiac expression of eNOS (C: 100 ± 6%; OVX-D: 59 ± 2%*; G-1: 86 ± 2%
#
) but the agonist did not alter cardiac AT1 receptor expression (C: 100 ± 14%; OVX-D: 163 ± 11%*; G-1: 174 ± 9%*). We detected no change in uterine weight of the OVX-D rats treated with G-1 suggesting no crossover of the agonist with the steroid receptors ERα or ERβ (C: 0.68 ± 0.07; OVX-D: 0.14 ± 0.01*; G-1: 0.14 ± 0.01*g). In conclusion, the present study suggests that selective activation of a novel GPR30 receptor may attenuate cardiac injury in estrogen- and insulin-depleted mRen2.Lewis rats by reducing blood pressure and preserving eNOS pathway.
Abstract 318: The Cardiotonic Bufodienolide Steroid Marinobufagenin Alters Messenger RNA Concentrations of Soluble Flt-1 in Human Brain Microvascular Endothelial Cell Monolayers
Authors: Ing Nancy , Balog-Alvarez Cynthia , Abi-Ghanem Daadoun , Berghman Luc , Puschett Jules B
Published: March 2022

Previous studies from this laboratory have provided evidence that, in a rat model of preeclampsia (PE), the cardiotonic bufodienolide, marinobufagenin (MBG), is not only a biomarker but an etiologic factor. Concentrations of MBG in blood and urine are increased in women with PE compared to those with normal pregnancies. Additionally, MBG has been determined in both in vivo and in vitro studies to cause vascular leak. Those studies included direct evidence that MBG causes hyperpermeability of endothelial monolayers. Because PE patients may exhibit neurologic abnormalities often associated with cerebral edema, we examined the effects of MBG on endothelial monolayers obtained from human brain microvasculature. Since PE has also been determined to alter concentrations of factors that affect angiogenesis, we investigated the effects of treatment with 10-8 M MBG on primary cultures of endothelial cells from human brain microvasculature on concentrations of mRNAs encoding the VEGF receptor called soluble Flt-1 (Flt-1 variant 2 mRNA) and Flt-1 mRNA variant 3, as well as NF kappa B (NFKB1), a substance often involved in tissue injury. MBG depressed the concentrations of Flt-1 mRNA within 2 h, with the largest effect (reduced to ½) at 12 h compared to vehicle treated controls. The effect was reversed at 24 h, when MBG-treated endothelial cells contained 2.4-fold higher Flt-1 mRNA. Throughout the time course, Flt-1 variant 3 and NFKB1 mRNA levels were unchanged. These studies are currently being extended with microarray analyses of the global transcriptome of MBG-treated and control cultures of endothelial cells from human brain microvessels.
Abstract 323: Resveratrol Attenuates Pressure Overload-induced Heart Failure
Authors: Supowit Scott , Gupta Prakash , Singh Ugra , DiPette Donald
Published: March 2022

The purpose of this study was to determine whether the potent antioxidant, resveratrol, attenuates the adverse cardiac remodeling and dysfunction in pressure overload heart failure induced by transverse aortic constriction (TAC). Male C57BL6 mice (26-28 g) were subjected to either sham or TAC surgery. One group of TAC mice was given daily resveratrol treatment (oral gavage, 100 mg/kg/body weight (bw) for 28 days starting on day 2 after surgery. Echocardiographic, biometric, and immunohistological analyses were performed on the three groups of mice. All echocardiographic parameters examined (internal diameters, fractional shortening , and ejection fraction) demonstrated significantly greater adverse cardiac remodeling and dysfunction in the TAC compared to the sham mice. These pathological changes were significantly improved by resveratrol treatment. At day 28 fractional shortening was 46.5±2.4%, 26.2±2.0%, and 35±2.6% in the sham, TAC, and TAC + resveratrol mice, respectively. This was reflected by lung weight/bw ratios of 4.2±0.3 mg/g (sham), 8.6±0.9 mg/g (TAC) and 7.2±0.4 mg/g (TAC + resveratrol). Resveratrol treatment also significantly reduced cardiac hypertrophy as determined by the heart weight/bw ratios (sham, 4.8±0.3 mg/g; TAC, 8.7±0.6 mg/g; and TAC + resveratrol, 7.2±0.3 mg/g). Likewise, the TAC protocol significantly increased fibrosis (10.0±1.1%), compared to the sham-operated mice (0.7±0.3%), which was attenuated by resveratrol treatment (3.0±0.5%). Similar results were obtained when cardiomyocyte apoptosis was assessed. Both superoxide dismutase 2 and hypoxia inducible factor 1α were markedly increased in the TAC compared to the sham-operated mice most likely as a compensatory response to increased oxidative stress and hypoxia. These TAC-induced factors were significantly decreased by resveratrol treatment indicating that the resveratrol was acting in place of these stress inducible factors. In summary, these results demonstrate that resveratrol treatment significantly attenuates the adverse cardiac remodeling and dysfunction produced by the TAC protocol in C57/BL6 mice and that this activity is mediated, at least in part, by the inhibition of oxidative stress and hypoxia.
Abstract 325: Cardiac Hypertrophy in Spontaneous Hypertensive Rats (SHR) is Associated With Decreased Cardiac Expression of SIK1 and SIK3 Isoforms
Authors: Pinho Maria J , Bertorello Alejandro M , Soares-da- Silva Patricio
Published: March 2022

Numerous reports have highlighted the importance of protein kinases and transcription factors in cardiogenesis and cardiac hypertrophy. The salt-inducible kinase 1 (SIK1), a protein kinase encoded by the snf1lk gene, is involved in early cardiogenesis in mice. Genotype-phenotype association studies in three Swedish and one Japanese population-based cohorts suggested that 15Ser-SIK1 variant (15Gly-Ser change, T allele), bestow augmented SIK1 activity, was associated with lower blood pressure and decreases in left ventricular (LV) mass. The present study aims to determine the potential role of SIK1 as a mediator of cardiac hypertrophic signaling pathway and to evaluate age-related changes on the cardiac expression of several elements of the SIK network associated with hypertension, in Wistar Kyoto (WKY) and spontaneously hypertensive rats (SHR). For this purpose, mRNA expression levels of skeletal actin (SkA), β-myosin heavy chain (β-MHC) and matrix metalloproteinase-9 (MMP-9) as markers for cardiac hypertrophy, SIK isoforms (SIK1, SIK2 and SIK3), and transcription factors (MEF2C, NFAT5c, KFL4, Snail1 and Snail2) were determined, using Taqman, in 13- , 52- and 91-week old SHR and their normotensive counterparts WKY. Systolic and diastolic blood pressures, determined by the tail-cuff method, were significantly higher in 3- , in 3- , 13- and 21-month old SHR than in age-matched WKY. In the SHR, increases in heart/tibia length ratio were associated to the overexpression of cardiac hypertrophic genes (SkA and β-MHC) and the underexpression of cardiac SIK3, at the age of 3- , 13- and 21-months. Ageing accompanied by a diminished mRNA expression of SIK1 in SHR, relative to WKY (both at 13- and 21-months of age). Whereas, Snail2, MFAT5c and KLF4 mRNA levels decreased with aged SHR, comparing to age-match WKY (both at 13- and 21-months of age). These results indicate that SIK1 and SIK3 isoforms might be upstream mediators of transcriptions factors implicated in the regulation of cardiac hypertrophic growth response. In conclusion, ageing in SHR is accompanied by cardiac alterations that include hypertrophy and dysfunction of the SIK signaling network. Supported by grant PIC/IC/83204/2007.
Abstract 326: Valvular Regurgitations May Increase Arrhythmias in Hypertensive Heart Failure in Blacks
Authors: Ajayi Adesuyi A , Akintomide Anthony O , Ajayi Olufemi E
Published: March 2022

Hypertensive heart disease(HHD) in Nigerians, is associated with concentric LVH and a high frequency of early valvular regurgitations (VR). HHD is the commonest cause of sudden cardiac death (SCD) in that population, but the role of arrhythmias in these is not known. We therefore (a)investigated the relationship between VR and cardiac arrhythmias in normotensives, hypertensives, and hypertensive heart failure (HHF) in Nigerians and (b) examined the hypothesis that VR increases the prevalence and complexity of cardiac arrhythmias in HHF Nigerians. HHF patients (n=14), HHD patients (n= 23) and Normal controls (N) n=9 underwent 24 hr Holter EKG monitoring and 2D and Doppler Echocardiography, and the presence or absence of VR noted in each individual and groups. Each patient group was sub classified into those with VR or without VR (NVR). There were significant between patient group differences in SVT P<0.001ANOVA),mean and median VT frequency (p <0.02) and ventricular couplets (p= 0.0002 ANOVA). HHF with VR had more SVT (81/24HRS) than HHF with NVR (4/24HRS) p = 0.016, as well as more VT/Triplets(69/24HRS) than HHF-NVR (34/24HRS) p <0.02 . HHF with VR had more couplets 446/24HRS than HHF-NVR (58/24HRS) p _ 3 VALVES) had the greatest number of dangerous arrhythmias with VT 6/11 or 55%, but only 3/19 ( 19%) in NVR .

The number of regurgitant valves was positively correlated both to the frequency and the Lown class of arrhythmias (0-IVB)( r = 0.42 p=0.003, n=46), and to VT frequency/episodes ( r = 0.30, p=0.04 ANOVA , n=46). HHF with VR had lower EF but higher LVH compared to HHF NVR (p <0.05). These results support the role of valvular regurgitation in cardiac arrhythmogenesis and complex ventricular ectopy perhaps through connexin43 modification and LVH in HHD, and HHF.
Abstract 330: Relationship Between On-Treatment Decreases in Inappropriate Versus Absolute or Indexed Left Ventricular Mass and Increases in Ejection Fraction in Hypertension
Authors: Woodiwiss Angela J , Libhaber Carlos D , Libhaber Elena , Sareli Pinhas , Norton Gavin R
Published: March 2022

Although in cross-sectional studies left ventricular mass (LVM) which exceeds that predicted by work load (inappropriate LVM [LVM
inappr
]), but not absolute LVM or LVM index, is inversely related to LV ejection fraction (EF), whether LVM
inappr
(%observed/predicted LVM) accounts for decreases in EF is unclear. In 168 mild-to-moderate hypertensives treated for 4 months, using echocardiography, we assessed whether on-treatment decreases in absolute LVM, LVM index (LVMI) or LVM
inappr
are associated with on-treatment changes in EF. Although in patients with an LVMI>51g/m
2.7
(n=112)(change in LVMI=-13.7±1.2g/m
2.7
, p<0.0001), but not in patients with an LVMI≤51g/m
2.7
(n=56)(change in LVMI=1.3±1.7g/m
2.7
) LVMI decreased with treatment; treatment failed to increase EF in either group (1.2±1.0% and 2.7±1.4% respectively). In contrast, in patients with inappropriate LV hypertrophy (LVH) (LVM
inappr
>150%, n=33) LVM
inappr
decreased (-32±4%, p<0.0001) and EF increased (5.0±1.8%, p<0.0001) after treatment, whilst in patients with a LVM
inappr
≤150% (n=135), neither LVM
inappr
(-0.5±2%), nor EF (0.9±0.9%) changed with therapy. With adjustments for LV wall stress and other confounders, whilst on-treatment decreases in LVM or LVMI were weakly related to an attenuated EF (partial r=0.17, p<0.05), on-treatment decreases in LVM
inappr
were strongly related to increases in EF (partial r=-0.38, p<0.0001)(p<0.0001, comparison of partial r values) even after further adjustments for LVM or LVMI. In conclusion, decreases in LVM
inappr
but not LVM or LVMI are strongly related to on-treatment increases in EF. LVH can therefore be viewed as a compensatory change that preserves EF, but when in excess of that predicted by stroke work, as a pathophysiological process accounting for a reduced EF.
Abstract 332: Phosphoprotein Abundance Changes in Hypertensive Cardiac Remodeling
Authors: Kotlo Kumar , Johnson Keven , Grillon Jean , Geenen David , De Tombe Pieter , Danziger Robert S
Published: March 2022

There is over-whelming evidence that protein phosphorylations regulate cardiac function and remodeling. A wide variety of protein kinases, e.g., phosphoinositide 3-kinase (PI3K), Akt, GSK-3, TGFβ, and PKA, MAPKs, PKC, Erks, and Jaks, as well as phosphatases, e.g., phosphatase I (PP1) and calcineurin, control cardiomyocyte growth and contractility. In the present work, we used global phosphoprotein profiling to identify phosphorylated proteins associated with pressure overload (PO) cardiac hypertrophy and heart failure. Phosphoproteins from hypertrophic and systolic failing hearts from male hypertensive Dahl salt-sensitive rats; trans-aortic banded (TAC); Spontaneously hypertensive heart failure (SHHF) rats were analyzed. Profiling was performed by 2-dimensional difference in gel electrophoresis (2D-DIGE) on phosphoenriched proteins. A total of 25 common phosphoproteins with differences in abundance in 1) the 3 hypertrophic and /or 2) the 2 systolic failure heart models were identified (CI > 99%) by Matrix assisted Laser Desorption Ionization Mass Spectrometry (MALDI-MS) and Mascot analysis. Among these were 1) myofilament proteins, including alpha-tropomyosin and myosin regulatory light chain 2; cap Z interacting protein (cap ZIP), and tubulin β5; 2) mitochondrial proteins, including pyruvate dehydrogenase α, branch chain ketoacid dehydrogenase E1, and mitochondrial creatine kinase 3) phosphatases, including protein phosphatase 2A and protein phosphatase 1 regulatory subunit and 4) other proteins including proteosome subunits α type 3 and β type 7, , and eukaryotic translation initiation factor 1A (eIF1A). These include previously described and novel phosphoproteins in cardiac hypertrophy and systolic failure. The database of phosphoproteins identified may provide new insights and therapeutic targets for heart failure.
Abstract 335: Isolated Baroreflex Dysfunction May Impair Renal Function
Authors: Paulini Janaina , Jorge Luciana , Moreira Edson D , Irigoyen Maria Claudia
Published: March 2022

Autonomic and renal dysfunctions are common chronic conditions that frequently coexist in the same individual, and both are associated with significant morbidity and mortality.

Aim:
To evaluate if total arterial baroreflex abolishment leads to alterations in renal function.

Methods:
Wistar rats divided into: control (n=9) and SAD (n=9). Sinoaortic denervation (SAD) was performed using the method previously described by Krieger (1964). Metabolic cage was used to evaluate
in vivo
renal function. BP and HR signals were recorded using a data acquisition system (Codas, 2 kHz). Autonomic function was evaluated by spectral analysis. Colored microspheres (CM) were infused into the left ventricle to determine renal blood flow and resistance changes quantified by spectrophotometry.
Ex vivo
renal perfusion was used to measure renal function.

Results:
Neither BP (C: 106 ± 2 vs. SAD: 108 ± 2 mmHg) nor HR (C: 355 ± 7 vs. SAD: 357 ± 15 bpm) were modified by SAD. HRV was decreased in SAD (43 ± 5 vs. C: 103 ± 12 ms2). However, BPV and LF component of BPV, respectly, were increased in SAD (46 ± 10; 6 ± 0.5 mmHg2) compared to C (35 ± 6; 2.6 ± 2 mmHg2). Although BP was similar between groups, it was observed a reduction in cardiac output in denervated animals (85 ± 6 vs. C: 111 ± 7 mL/min, p=0.02) and an increase in total peripheral resistance (1.25 ± 0.03 vs. C: 0.97 ± 0.02 mmHg/mL/min). These alterations resulted in a decreased plasmatic renal flow in SAD group (1.49 ± 0.18 vs. 3.47 ± 0.21 mL/min/g). Water intake and urine volume were higher in SAD (34 ± 1 mL/24h; 26 ± 6 mL) compared to C (25 ± 2 mL/24h; 8 ± 1 mL) and SAD showed proteinuria (0.03 ± 0.01
vs.
C: 0.015 ± 0.0005 g/24h).
Ex vivo
evaluations demonstred a decreased urinary flow (0.07 ± 0.01
vs
. C: 0.15 ± 0.01 mL.g-1.min-1) and glomerular filtration rate in SAD group ( 0.5 ± 0.1 vs. C: 0.3 ± 0.01 mL.g-1.min-1). Our data suggest that total baroreflex impairment leads to a renal and peripheral autonomic dysfunction, since SAD induced proteinuria and increased BPV, both markers of functional organ damage. Moreover, even without neurohumoral influence the kidneys from SAD group was not able to work properly. In conclusion, the results obtained in this study provide evidence that the homeostatic role of the baroreflex is essential in the course of changes of renal function.