bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 094: Cox2 Inhibition During Decidualization Improves Fetal Growth Restriction In The BPH/5 Mouse Model Of Preeclampsia
Authors: Sones Jenny L , Butler Scott D , Isroff Catherine E , Cha Jeeyeon , Dey Sudhansu K , Davisson Robin L
Published: July 2021

Preeclampsia (PE) presents as maternal hypertension and proteinuria during the second half of pregnancy and often results in preterm delivery of a growth restricted baby. Despite being a leading cause of perinatal and maternal morbidity/mortality, the underlying mechanism(s) is unknown. Because signs resolve upon delivery of the placenta, abnormal placentation is widely accepted as the cause of PE. BPH/5 mice spontaneously develop the cardinal features of PE along with poor fetoplacental outcomes, such as fetal growth restriction. We have shown that BPH/5 implantation sites exhibit significant up-regulation of
Ptgs2
(the gene encoding Cox2) at e7.5 as compared to C57. Since Cox2 and Cox2-derived prostaglandins (PGs) are crucial for uterine decidualization and placental angiogenesis, we tested the hypothesis that BPH/5 mice have dysregulated PG synthesis during decidualization and that this contributes to poor fetoplacental outcomes. Because e7.5 is considered the peak of decidualization, we designed experiments to selectively target Cox2 at this time in BPH/5 implantation sites. Administration of celecoxib by oral gavage at e6.5 (10mg/kg BW) caused a 2-fold reduction in Cox2 protein expression in BPH/5 implantation sites at e7.5 (n=3-4; p<0.05 vs BPH/5 veh). This had no effect on Cox2 levels in C57. This was associated with a significant reduction in PGE
2
synthesis (51.6±17.3 vs veh: 135.6±49.7 pg/mg), but not PGI
2
in e7.5 BPH/5 implantation sites (n=4-5; p<0.05). Neither PGE
2
nor PGI
2
synthesis was altered in C57 implantation sites. Furthermore, celecoxib improved fetal growth restriction in BPH/5 pups at e18.5 (1.108±0.091 vs veh: 1.036±0.021g), which was associated with an increase in placental weight (99.7±1.6 vs veh: 91.32±2.2mg) in BPH/5 females (n=20-38; p<0.05). These results provide evidence that Cox2 and PGE
2
play a key role in fetoplacental development in a mouse model of PE,

and that celecoxib improves fetal outcomes in BPH/5 females. This highlights the significance of proper decidual angiogenesis and suggests that aberrations in these processes in early pregnancy may contribute to fetal growth restriction seen in PE pregnancies.
Abstract 212: Fractalkine Neutralization Improves Cardiac Function After Myocardial Infarction
Authors: Gu Xiaosong , Xu Jiang , Yang Xiao-Ping , Peterson Edward , Harding Pamela
Published: July 2021

Background:
Circulating levels of the chemokine fractalkine (FKN) are increased in patients with chronic heart failure (HF) and our studies show that aged mice lacking the prostaglandin E2 EP4 receptor subtype (EP4 KO) have increased cardiac FKN coupled with a phenotype of dilated cardiomyopathy. However, whether FKN is a causal factor for HF is not well established.

Hypothesis:
FKN contributes to the pathogenesis of HF post myocardial infarction (MI) and EP4 KO mice have a better response to anti-FKN treatment due to elevated FKN levels.

Methods:
Male EP4 KO mice and wild type (WT) littermates underwent surgery to induce MI. Mice were treated with an anti-FKN antibody (40μg/kg/day, ip) or IgG immediately after MI and echocardiography was performed 2 wks post MI. Hearts were excised for infarct size determination, myocyte cross-sectional area (MCSA) and interstitial collagen fraction (ICF) determined by morphometric analysis and macrophage infiltration using immunohistochemistry.

Results:
Anti-FKN treatment improved cardiac function and prevented remodeling (Table). In situ zymography revealed that gelatinase activity was markedly reduced by anti-FKN treatment in both strains. Moreover, anti-FKN treatment tended to improve survival in EP4 KO mice (p = 0.06, n=20).

Conclusions:
(1) FKN contributes to the pathogenesis of HF and anti-FKN treatment improves cardiac function and reduces cardiac remodeling. This may be related to reduced macrophage infiltration and decreased gelatinase activity.(2) Contrary to our hypothesis, EP4 KO mice do not have an enhanced response to anti-FKN treatment.
Abstract 225: Treatment with LCZ696, an Orally Active Angiotensin Receptor Neprilysin Inhibitor Prevents Ischemic Brain Damage
Authors: Bai Hui-Yu , Mogi Masaki , Nakaoka Hirotomo , Kan-no Harumi , Tsukuda Kana , Chisaka Toshiyuki , Wang Xiao-Li , Kukida Masayoshi , Shan Bao-Shuai , Iwanami Jun , Horiuchi Masatsugu
Published: July 2021

Objective:
Recent accumulating evidence suggests that an orally active angiotensin II receptor-neprilysin inhibitor, LCZ696, was supposed to be superior compared to angiotensin II receptor blocker (ARB), valsartan alone in treating cardiovascular disease. We previously reported that ARBs prevent ischemic brain damage using middle cerebral artery occlusion (MCAO) mouse model. Moreover, natriuretic peptides such as atrial natriuretic peptide (ANP) or brain natriuretic peptide (BNP) increased by neprilysin inhibitor are also reported to protect brain damage. Therefore, we investigate the possible protective effects of valsartan (VAL) compared with LCZ696 (LCZ) (VAL+ neprilysin inhibitor; 1:1) on the prevention of ischemic damage after stroke.

Methods:
Focal brain ischemia was induced by MCAO with the intraluminal filament technique in 10-week male C57BL/6J mice. Mice were treated with VAL (3 mg/kg) or LCZ (6 mg/kg) orally as powder in gelatin mini-capsules daily for 2 weeks before MCAO. Ischemic area was evaluated by triphenyl tetrazolium chloride staining, cerebral blood flow (CBF) by laser-Doppler flowmetry, oxidative stress by dihydroethidium staining.

Results:
Telemetry method showed that systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate (HR) did not change before and after treatments. Protective effect of LCZ treatment on ischemic brain damage in each brain section seemed to be more marked than that of VAL treatment. The average ischemic area ratio showed a significant reduction in VAL and LCZ groups compared with CON group. CBF in the peripheral region around ischemic core was significantly improved after treatments. Moreover, VAL and LCZ treatments significantly decreased the increase of superoxide anion production in the cortex of ischemic side. However, significant differences of CBF and superoxide anion production were not observed in VAL and LCZ.

Conclusions:
Both valsartan and LCZ696 treatments exerted preventive effects on ischemic stroke. The preventive effect of LCZ696 seemed more prominent than VAL. LCZ696 could be a novel powerful approach to protect brain after stroke. Further investigation has been performed to clarify the protective effect of LCZ696 on ischemic brain damage.
Abstract 236: Intrauterine Growth Restriction Programs A Reduction In Nitric Oxide Bioavailability Indicative Of Accelerated Vascular Aging In The Male Growth-restricted Rat.
Authors: Dasinger John Henry H , Intapad Suttira , Backstrom Miles A , Alexander Barbara T
Published: July 2021

Intrauterine growth restriction (IUGR) programs hypertension and endothelial dysfunction at 4 months of age in male IUGR rat offspring compared to male control. Male IUGR offspring at 4 months of age exhibit a significant decrease in the blood pressure (BP) response to chronic NG-nitro-L-arginine methyl ester (L-NAME, 10mg/kg/day) compared to age-matched male control. Albuminuria is also significantly reduced in L-NAME treated male IUGR relative to L-NAME treated male control suggesting that IUGR programs a reduction in bioavailability of nitric oxide (NO). Decreased NO bioavailability by endothelial dysfunction can contribute to increased BP. Age is a risk factor for hypertension and aging is associated with an increase in arterial stiffening and endothelial dysfunction. BP is similar in male IUGR relative to male control by 18 months of age. Thus, this study tested the hypothesis that age-induced reductions in NO bioavailability in the male control rat would abolish the IUGR-induced differential BP and albuminuria response to chronic L-NAME observed in male IUGR rats in young adulthood. To test this hypothesis male control and IUGR rats were treated with L-NAME or vehicle at 18 months of age. Animals underwent weekly 24 hour metabolic studies initiated prior to and during chronic L-NAME; BP was measured in conscious, chronically instrumented animals. As previously observed BP did not differ in untreated male control versus untreated male IUGR (151±4 vs. 153±4 mmHg); however, BP did not differ following chronic treatment with L-NAME in male control versus male IUGR (188±5 vs. 196±9 mmHg); control vs. IUGR, respectively. Thus, age attenuated the differential BP response to chronic L-NAME. Albumin excretion did not differ in male control versus male IUGR prior to initiation of L-NAME (81±11 vs. 96±27 mg/day) or following chronic treatment with L-NAME (127±26 vs. 107±24 mg/day); control vs. IUGR, respectively. Thus, these data suggest that IUGR programs a reduction in NO bioavailability in young adulthood implicating that IUGR programs accelerated vascular aging. Additional studies are needed to understand mechanism and facilitate the development of preventative measures against the intrauterine programming of cardiovascular risk.
Abstract 281: Long-term Exposure of PM2.5 Causes Hypertension by Impaired Renal D1 Receptor Mediated Sodium Excretion via Up-regulation of GRK4 Expression in SD rats
Authors: Lu Xi , Chen Ken , Zeng Jing , Ren Hongmei , Zeng Chunyu
Published: July 2021

Introduction:
Epidemiological evidence supports an important association between PM2.5 exposure and hypertension. There are reports that PM2.5 induced hypertension with impaired sodium excretion, however, the mechanisms are not clear.

Hypothesis:
We hypothesize that PM2.5, via increased ROS levels, increased GRK4 expression, consequently impaired renal D1 receptor function, and lead to hypertension.

Methods:
We used Sprague-Dawley (SD) rats with in-vivo PM2.5 exposure, and immortalized renal proximal tubule (RPT) cells from Wistar-Kyoto (WKY) rats in-vitro, which behave similarly to freshly obtained RPT cells.

Results:
Our present study found that long-term exposure of PM2.5 caused hypertension and impaired renal sodium excretion, which might be ascribed to lower D1 receptor expression and higher D1 receptor phosphorylation, accompanied with higher GRK4 expression. The in-vivo results were confirmed in in-vitro study, i.e. PM2.5 increased basal Na+-K+ ATPase activity, decreased D1 receptor mediated inhibitory effect on Na+-K+ ATPase activity, decreased D1 receptor expression and increased D1 receptor phosphorylation in RPT cells. The downregulation of D1 receptor expression and function might be due to higher GRK4 expression, because down-regulation of GRK4 by siRNA reversed the D1 receptor expression and function. Due to the role of ROS on D1 receptor dysfunction, we checked ROS levels, and found plasma ROS levels were higher in PM2.5 treated SD rats. Inhibition of ROS by tempol reduced blood pressure and increased sodium excretion in PM2.5 treated SD rats, accompanied by increased the lower D1 receptor expression, and decreased the hyperphosphorylated D1 receptor and GRK4 expression.

Conclusions:
Long-term exposure of PM2.5 increases blood pressure by decreased D1 receptor expression and function; ROS, via regulation of GRK4 expression, is taken part in the pathogenesis of PM2.5-induced hypertension.
Abstract 304: A Moderately- Enriched Fructose Diet Increases The Sensitivity Of The Proximal Nephron To Angiotensin II.
Authors: Gonzalez-Vicente Agustin , Hong Nancy J , Cabral Pablo D , Garvin Jeffrey L
Published: July 2021

Consumption of high-fructose corn syrup as a sweetener has been implicated in diabetes, obesity, and hypertension. We have recently shown that a moderately-enriched fructose diet (20%), an amount consumed by more than 30 million Americans, causes salt-sensitive hypertension. Activation of the renin-angiotensin system in the proximal nephron also increases blood pressure presumably due to augmented salt and water reabsorption. However, whether the effects of angiotensin II (Ang II) on proximal tubule transport are enhanced by moderate fructose consumption is unknown. We hypothesize that a diet containing moderate amounts of fructose increases transport in proximal tubules by enhancing their sensitivity to Ang II. To test this, we measured the effects of Ang II on transport-related oxygen consumption (QO2) in proximal tubule suspensions from rats consuming 20% of their calories as fructose in their drinking water for 1 week. We found that 1 pmol/l Ang II stimulated QO2 by tubules from the fructose-fed group but had no effect on those from controls (21 ± 7 vs. 5 ± 3 nmol/mg/min; p < 0.04, n = 7). In contrast, basal QO2 rates were not affected (94 ± 1 vs. 95 ± 4 nmol O2/mg/min, n = 7). Addition of 100 pmol/l Ang II stimulated QO2 to the same extent in both groups (19 ± 8 vs. 18 ± 8 nmol O2/mg/min; n = 7). AT1 receptor mRNA expression in cortical homogenates was not different between groups (8961 ± 454 vs. 8712 ± 575 AU; n = 4). Both groups gained weight at the same rate. We conclude that moderate dietary fructose consumption increases the sensitivity of the proximal nephron to Ang II independently of AT1 expression, and this may contribute to the salt sensitivity of this model.
Abstract 317: Mas Receptor Deficiency Increases Blood Pressure Of Female Obese Mice
Authors: Wang Yu , Shoemaker Robin , Cassis Lisa
Published: July 2021

Objective:
We recently demonstrated that female mice were protected from high fat (HF) diet-induced obesity hypertension. Protection of females from obesity-hypertension was associated with an activation of angiotensin converting enzyme 2 (ACE2) in adipose tissue as well as increased plasma concentrations of the ACE2 product, angiotensin-(1-7) (Ang-(1-7)). Previous investigators demonstrated that antagonism of Mas receptors (MasR), receptors for Ang-(1-7)-induced blood pressure regulation, abolished protection of female spontaneously hypertensive rats from angiotensin II (AngII)-induced hypertension. Taken together, these results suggest that activation of MasR protects females from obesity-induced hypertension. We hypothesized that MasR deficiency will abolish protection of female HF-fed mice from the development of obesity-induced hypertension.

Methods and Results:
Female (8 weeks old, C57BL/6 background) wild type (MasR+/+) and whole body MasR deficient mice (MasR-/-) were fed a HF diet (60% Kcal as fat) for 16 weeks. MasR deficiency had no effect on the development of diet-induced obesity (MasR+/+, 45 ± 2; MasR-/-, 46 ± 2 g). In addition, MasR deficiency had no significant effect on glucose tolerance of HF-fed mice (area under the curve for blood glucose concentrations: MasR+/+, 27766 ± 1675; MasR-/-, 26275 ± 1385). At 15 weeks of HF feeding, carotid artery catheters and radiotelemetry implants were implanted into anesthetized mice, and following 1 week of recovery, blood pressure was quantified for 3-5 days. Deficiency of MasR resulted in a significant increase in diastolic blood pressure (DBP) of HF-fed females compared to controls (24hr average: MasR+/+, 88 ± 2 mmHg; MasR-/, 93 ± 2 mmHg; P<0.05). However, modest elevations in systolic blood pressure (24 hr average: MasR+/+, 125 ± 2 mmHg; MasR-/-, 128 ± 2 mmHg; p=0.38) and mean arterial pressure (24 hr average: MasR+/+, 107 ± 2 mmHg; MasR-/-, 111 ± 2 mmHg; p=0.16) of HF-fed female MasR deficient mice were not statistically significant.

Conclusion:
Deficiency of MasR promoted elevations in diastolic blood pressure of female obese mice. These results suggest that the ACE2/Ang-(1-7)/MasR axis contributes to protection of obese females from obesity-induced hypertension.
Abstract 318: The Role of PKC-alpha in NCC-Mediated Hypertension
Authors: Wynne Brandi M , Molina Patrick , Klein Janet D , Hoover Robert S
Published: July 2021

The sodium-chloride cotransporter (NCC) is an essential regulator of sodium transport in the distal convoluted tubule (DCT); functional aberrations will lead to dysregulation of blood pressure. Although this role is well-accepted, the mechanisms accounting for increased distal nephron sodium reabsorption is not completely understood. Previously published data from the Pharmacogenomic Evaluation of Antihypertensive Responses (PEAR) Study has demonstrated that a polymorphism in PKC-alpha may lead to an increased sensitivity to thiazide diuretics. To investigate whether PKC-alpha may be altering blood pressure via NCC, PKC-alpha KO (PKC KO) and PKC Control (Ctl) mice were used to measure blood pressure via radiotelemetry after normal and high salt (HS, 4%) dietary manipulations and Western blot analysis performed using kidney lysates. Using radiotelemetry (DSI) measurements obtained over an 18 hour ‘active’ time period, we report a significant increase in mean arterial pressure (MAP) in the PKC KO mice as compared to control (123.2±1.1 mmHg vs. 102.0±0.77 mmHg, p<0.001). With HS feeding, MAP increased in both groups; in addition MAP remained significantly higher in the PKC KO mice as compared to the Ctl after 21 days (139.5±0.3 mmHg vs. 124.7±1.1 mmHg, p<0.01). To determine a possible mechanism for this phenomenon, whole kidney lysate was used to assay for total NCC protein. Total NCC protein was almost 3 fold higher in the PKC KO mice as compared to Ctl (in arbitrary units, 208±16 vs. 61±30, p<0.01). Herein we report that lack of PKC-alpha leads to an increase in MAP, which may be accounted for by increased total NCC expression and a subsequent increase in distal nephron reabsorption. We believe that PKC-alpha may be negative regulator of NCC protein expression, and that aberrations in this pathway will lead to hypertension.
Abstract 323: Impaired PVN Neuronal Activity In Rats Lacking Central Gαi2 Proteins: Implications For The Pathophysiology Of Salt-Sensitive Hypertension
Authors: Carmichael Casey Y , Carmichael Alana C , Vartanyan Philip , Wainford Richard D
Published: July 2021

Aim:
We have demonstrated downregulation of central Gαi
2
proteins produces global sympathoexcitation and elevated MAP in response to
acute
and
chronic
high-salt challenge. The current study sought to define whether alterations in PVN neuronal activity in rats lacking brain Gαi
2
proteins underlie the sympathoexcitatory and pressor responses observed upon
acute
and
chronic
high-salt challenge.

Methods:
In
acute
studies, 24-h ICV scrambled (SCR) or Gαi
2
oligodeoxynucleotide (ODN; 25μg/5μl)-pretreated conscious Sprague-Dawley rats were monitored for changes in MAP in response to IV bolus NaCl (3M; 0.14 ml/100g). Rats were sacrificed at control, 10-, 40-, or 100-min post IV NaCl and cFos IHC was performed. In
chronic
studies, rats receiving an ICV miniosmotic-pump infusion of Gαi
2
or SCR ODN (25μg/day) were maintained on a normal (NS; 0.4% NaCl) or high (HS; 8% NaCl) salt diet for 7 days and sacrificed for FosB IHC (N=6/gp).

Results:
In response to IV sodium, in SCR rats MAP returned to control levels by 100-min whereas Gαi
2
rats remained significantly elevated (MAP 100-min post NaCl [mmHg] SCR: 134±2 vs. Gαi
2
: 146±3, P<0.05). At 40-min post NaCl, a significant reduction in Fos immunoreactivity was observed in SCR but not Gαi
2
rats ([PVN cFos
+
cells] SCR control: 168±21
vs
. post NaCl: 39±16, p<0.05, Gαi
2
control: 155±18
vs
. post NaCl: 116±16). Additionally, Gαi
2
prevented the Na
+
induced decrease of circulating plasma NE at 100-min (Δplasma NE [%control] SCR: -8.46±1.31 vs. Gαi
2
: +5.13±7.90, P<0.05). In SCR infused rats, a chronic HS diet evoked a significant decrease ([FosB
+
cells] NS: 224±13 vs. HS: 133±16, P<0.05) while a HS diet in Gαi
2
infused rats induced a significant increase ([FosB
+
cells] NS: 212±10 vs. HS: 296±15, P<0.05) in PVN FosB immunoreactivity.

Conclusion:
Gαi
2
proteins represent a novel CNS mechanism influencing PVN neuronal activity in an
acute
and
chronic
setting. Na
+
induced decreases in Fos
+
PVN cells in SCR rats likely reflect inhibition of neuronal activity to facilitate sympathoinhibition and physiological blood pressure control. In Gαi
2
rats, failure to inhibit PVN neuronal activity and sympathetic outflow represents a mechanism by which impairment of Gαi
2
signaling may contribute to the pathophysiology of salt-sensitive hypertension.
Abstract 420: Characterization of Dahl Salt-Sensitive Rat Model for Heart Failure with Preserved Ejection Fraction Research: Defining Diagnostic Criteria
Authors: Rolim Natale , Moreira Jose B , Medeiros Alessandra , Alves Marcia , Yang Xiaojuan , Gusky Till , Lesko Paulina , Bækkerud Fredrik H , Ness Henning O , Rolfseng Toril , Silva Gustavo J , Wisløff Ulrik
Published: July 2021

Heart failure with preserved ejection fraction (HFpEF) is a condition that accounts for approximately 50 % of heart failure cases with the prevalence increased with advancing age. As of now, no effective treatment is available for HFpEF, which calls for continued efforts towards novel therapies. Dahl salt-sensitive (Dahl SS) rats have recently been reported as an experimental model of HFpEF, although a specific diagnostic criteria for HFpEF is still unclear in rodents. We aimed to provide clear criteria to identify HFpEF in Dahl SS rats. After a follow-up of 28 weeks, adult female Dahl SS rats receiving high salt (HS, 8 % NaCl) diet developed chronic hypertension (209 ± 80 vs. 147 ± 55 mm Hg;
P
<0.05 vs. low salt-fed control group (LS, 0.3 % NaCl) with consistent left ventricle (LV) remodeling compared to LS rats (LV hypertrophy index: 2.62 ± 0.07 vs. 1.79 ± 0.03 mg/mm, and cardiomyocyte cross-sectional area: 497 ± 38.9 vs. 290 ± 8.15 μm
2
, respectively;
P
< 0.05) and EF > 50 % (67.7 ± 1.5 %). Evidence that HS rats have developed HFpEF was observed only in rats with left atrial dimension (LAD)/body weight (BW), E/A, and E/E’ ratios above the 75
th
percentile of the LS group (17.50 mm/kg, 1.53, and 14.25, respectively). In addition, HS rats diagnosed with HFpEF had increased LV end-diastolic pressure and plasma NT-proBNP compared to LS rats (12.8 ± 3.4 vs. 5.8 ± 0.8 mm Hg, and 78.7 ± 18.0 vs. 17.7 ± 3.5 pg/mL, respectively;
P
< 0.05), while no significant changes in LAD/BW, E/A, E/E’, and plasma NT-proBNP were demonstrated in HS rats not matching the suggested criteria for HFpEF. Distance run was not different between HS and LS groups. Survival rate was 39.9 % in HS compared to 94.7 % in LS rats (
P
= 0.0001), with stroke as the main cause of death (69.6 % incidence in HS rats). These results provide the first clear criteria for diagnosis of HFpEF in Dahl SS rats. Our findings have important implications for future preclinical studies aiming to develop novel therapeutic strategies targeting diastolic dysfunction in HFpEF.
Abstract 422: Cardiovascular Regulation in Mice with Overexpression of the Gene of Vesicular Acetylcholine Transporter (VAChT)
Authors: Tezini Geisa C , Guatimosim Silvia , Guimarães Diogo A , Oliveira Mauro , Fazan Rubens , Prado Marco A , Salgado Helio C
Published: July 2021

It was recently developed a transgenic animal model with overexpression of cholinergic neurotransmission. This mouse, named ChAT-ChR2-EYFP, has several extra copies of the vesicular acetylcholine transporter (VAChT) gene and exhibits three-fold increase in the release of acetylcholine. However, the consequences of overexpression of VAChT protein to the cardiovascular system have not yet been characterized. Therefore, we have investigated the effects of the overexpression of the gene of VAChT on arterial pressure (AP) and heart rate (HR) as well as the autonomic cardiovascular regulation. Mice were assigned into two groups: Wild-type (WT, n=7) and ChAT-ChR2-EYFP (n=7). These animals were anesthetized (isoflurane) and implanted with probes to record AP by telemetry. After 10 days, the mice had basal AP and HR recorded continuously. Assessment of the autonomic function was conducted throughout the following approaches: 1) cardiac sympathovagal balance evaluated by HR responses to methylatropine and propranolol; 2) overall HR variability; 3) spontaneous baroreflex sensitivity by the sequence analysis. ChAT-ChR2-EYFP mice showed lower basal HR (461±8 vs. 502±14 bpm, p<0.01) but similar AP as compared to WT mice. ChAT-ChR2-EYFP mice exhibited higher vagal tone (Δbpm, 169±14 vs. 117±6, p=0.03) and lower HR after double autonomic blockade (IHR, 456±8 vs. 509±11 bpm, p<0.001). HR variability was similar between groups (SDNN: 88±16 vs. 65±7 ms; RMSSD: 11.4±1 vs. 9.7±0.5 ms). However, the baroreflex sensitivity (7.5±1.5 vs. 4.1±0.5 ms/mmHg, p=0.05) was higher in ChAT-ChR2-EYFP mice. Altogether, the results show that the cardiovascular autonomic regulation of ChAT-ChR2-EYFP mice is characterized by higher parasympathetic tone, combined with a lower basal HR and IHR. Moreover, these mice present greater baroreflex sensitivity.
Abstract 443: Androgen-Sensitive Hypertension in Adult mRen2.Lewis Rats
Authors: Trimmer Emma H , Lindsey Sarah H
Published: July 2021

The mRen2.Lewis (mRen2) rat is an angiotensin II-dependent model of hypertension that displays marked sex differences in systolic blood pressure (SBP). Gonadectomy (GDX) of young female mRen2 rats significantly increases SBP; however, the role of androgens has not been assessed. In addition, the impact of GDX in adult rats with well-established hypertension is not known. Therefore, the current study assessed the impact of adult gonadectomy (GDX; 17 weeks of age) on established hypertension and associated end organ damage in mRen2 rats. Baseline SBP at 16 weeks of age was not different between male groups (214 ± 13 mmHg, n=5 vs. 224 ± 3 mmHg, n=3, P>0.05) but was significantly lower in females (143 ± 9 mmHg, n=3, P<0.01). GDX significantly lowered SBP in males after one week (159 ± 13 mmHg, P<0.001), and SBP remained lower until 25 weeks of age (169 ± 9 mmHg, P<0.05). The lower SBP in GDX males was associated with a significant reduction in kidney weight (3.1 ± 0.02 vs. 2.9 ± 0.06 mg/g body weight, P<0.05), heart weight (4.1 ± 0.10 vs. 3.4 ± 0.12 mg/g body weight, P<0.01), and proteinuria (53 ± 7 vs. 20 ± mg/kg/day, P<0.01) at 25 weeks of age. Proteinuria in GDX males remained significantly higher in comparison to GDX females (3.9 ± 0.6 mg/kg/day, P<0.01). In summary, GDX of adult male but not female mRen2 rats had a significant and rapid impact on blood pressure and was associated with a reduction in end organ damage. When combined with our previous work in the female mRen2 rat, we conclude that estrogens may play a critical role in the development of hypertension in younger females, while androgens apparently contribute to the maintenance of blood pressure in adult males. This animal model may be relevant to discern the complex relationships between sex hormones, hypertension, and tissue damage. Future studies will establish the molecular pathways by which each of these steroid hormones interacts with the renin-angiotensin system to modulate blood pressure in the mRen2 strain.
Abstract 453: Ablation of TRPV1 Impairs Exendin-4 Induced Suppression in Renal Cytokine Release
Authors: Zhong Beihua , Wang Donna H
Published: July 2021

Impairment of function and expression of the transient receptor potential vanilloid type 1 (TRPV1) occurs in obesity and diabetes, which may aggravate inflammation and tissue injury given that the TRPV1 mediated pathway has been shown to be anti-inflammatory. Glucagon-like peptide-1 (GLP-1), an incretin hormone released in response to food intake, is capable of protecting tissues from injury, but its mechanism largely unknown. We tested the

hypothesis that exendin-4 (Ex4), a GLP-1 receptor agonist, suppresses hypoxia-induced cytokine release via a TRPV1 mediated pathway. Using gene-targeted TRPV1-null mutant (TRPV1
-/-
) or wild-type (WT, C57BL/6) mice, plasma creatinine or urine
lactate dehydrogenase
(LDH) levels were measured 40- min after ischemia plus 3-hr reperfusion (I/R). Renal I/R increased plasma creatinine and urine LDH levels with a greater magnitude in TRPV1-/- than WT mice (creatinine, uM: WT: 99.4 ± 4.4 to TRPV1: 129.7 ± 11.9,
p
< 0.05; LDH, mU: WT: 132.3± 39.8 to TRPV1-/-: 178.5 ± 44.4,
p
< 0.05). In vitro, cytokine or chemokine secretion from renal tissues incubated either with 95% O
2
-5% CO
2
or 99% nitrogen (hypoxia) was measured. TNFα, IL-6, or MCP-1 release in response to nitrogen (1 hr) was increased in both strains with a bigger magnitude in TRPV1-/- than WT mice (p<0.05). Blockade of receptors for calcitonin gene-related peptide (CGRP) with CGRP8-38 (10
-7
M) further increased hypoxia-induced MCP-1 release in WT mice (p<0.05). Ex4 suppressed nitrogen (0.5hr)-induced cytokine/chemokine release from the kidneys in WT but not TRPV1-/-mice (WT: IL-6: 0.74 ± 0.08 to 0.66 ± 0.03; TNF-a: 0.73 ± 0.07 to 0.66 ± 0.03; MCP-1: 16.1± 3.5 to 12.7 ± 1.3 pg/g/min,
p
< 0.05. TRPV1-/-: p>0.05 for all). Moreover, Ex4 increased CGRP release from the renal pelvis in WT (
p
< 0.05) but not TRPV1 -/- mice, which can be inhibited by Ex9-39, an Ex4 antagonist. Thus, ablation of TRPV1 or blockade of CGRP receptors enhances hypoxia-induced inflammation and renal injury following I/R. Ex4 suppresses hypoxia-induced cytokine/chemokine release and enhances CGRP release from the kidney only when TRPV1 function and expression are intact, suggesting that TRPV1/CGRP may play a key role mediating Ex4-induced anti-inflammatory effects.
Abstract 466: Obstructive Sleep Apnea And Its Association With Endothelial Function, Oxidative Stress, Inflammation, Metabolic Profile, Blood Pressure And Sympathetic Activity In Obese Individuals
Authors: Araújo Luciene S , Fernandes Julia F , Valença Debora C , Rodrigues Maria de Lourdes G , Gomes Nathalia F , Carvalho Hadassa G , Gaspar Bernardo B , Neto José Firmino N , Klein Marcia R , Sanjuliani Antonio F
Published: July 2021

Background:
Obstructive sleep apnea (OSA) is associated with an increased risk of cardiovascular disease (CVD). Several of the proposed mechanisms for the development of CVD in OSA are similar to those proposed for the increased risk of CVD in obesity, being difficult to determine the influence of OSA on these pathogenic mechanisms in obese individuals.

Objectives:
The purpose of this study was to evaluate the relationship of OSA with endothelial function, oxidative stress, inflammatory biomarkers, metabolic profile, sympathetic nervous system activity and blood pressure (BP) in obese individuals.

Methods:
In this cross-sectional study, were included 53 obese adults (28 women). Sleep study was performed with Watch-PAT200® and the diagnosis of OSA was made when apnea-hipopnea index (AHI) ≥5 events/h (n=33). All participants underwent evaluation of: body adiposity, BP, plasma catecholamines, high sensitivity C-reactive protein (hs-CRP), adiponectin, malondialdehyde, glucose, insulin, lipid profile and endothelial function (Endo-PAT 2000®).

Results:
Mean age (39.6 ± 1.5 vs. 32.5 ± 2.1y) and percentage of male participants (61% vs. 25%) were significantly higher in participants with OSA than in those without OSA (p=0.01). In univariate analysis participants with OSA compared with those without OSA exhibited higher values of neck circumference (40.98 ± 0.63 vs. 38.65 ± 0.75 cm, p=0.02), glucose (92.54 ± 1.97 vs. 80.2 ± 1.92 mg/dL, p=0.0001), noradrenaline (0.16±0.02 vs. 0.12±0.03 ng/mL, p=0.02) and systolic BP (126.05 ± 1.61 vs. 118.16 ± 1.86 mmHg, p=0.003). After adjustment for confounders, only glucose and hs-CRP were significantly higher in OSA patients. In correlation analysis, after controlling for confounders, AHI was associated with neck circumference (r=0.31,p=0.03) and hs-CRP (r=0.30,p=0.04), while minimum O2 saturation was associated with neck circumference (r=-0.31,p=0.03), insulin (r=-0.29,p=0.04) and HOMA-IR (r=-0.30,p=0.04).

Conclusion:
The present study suggests that in obese individuals OSA is associated with inflammation and worse glycemia; higher AHI correlates with increased central adiposity and inflammation; and lower oxygen saturation is related with insulin resistance.
Abstract 475: Vasopressin Type 2 Receptor (v2r) Activation Increases Renin Expression In Renal Collecting Duct Cells.
Authors: Gonzalez Alexis A , Cifuentes Flavia , Ibaceta Cristobal , Zamora Leonardo , Prieto Minolfa C
Published: July 2021

Renin synthesis in juxtaglomerular cells (JGC) is mediated by intracellular cAMP accumulation and activation of PKA/CREB pathway. Recent evidence demonstrated that renin is expressed in renal collecting duct (CD) cells. Furthermore, it has been shown that CD renin is augmented in animal models of hypertension and kidney disease, despite the suppressed expression observed in JGC. Vasopressin activates V2R stimulating cAMP/PKA/CREB pathway and aquaporin-2 expression in apical plasma membrane of principal cells of the CD. We hypothesized that activation of V2R increases renin expression in mouse CD cell line M-1 through cAMP/PKA/CREB pathway. Desmopressin (ddAVP, 10-6 mol/L, 6 hrs), a specific V2R agonist, increased renin mRNA, prorenin protein levels in cell lysates and prorenin secretion to the culture media. To determine if this effect was related to PKA pathway, we used the PKA inhibitor H89. Co-treatment with ddAVP + H89 prevented the ddAVP-mediated increase in renin expression. To further confirm if the stimulation of renin synthesis in M-1 cells was mediated by cAMP accumulation, we raised intracellular cAMP levels using forskolin (10-7 mol/L). Forskolin treatment significantly increased renin mRNA and prorenin protein levels as compared to controls. Additionally, ddAVP increased phosphorylated CREB, while H89 blunted this effect. Finally, shRNA against CREB prevented the ddAVP-induced renin synthesis. We additionally confirmed the stimulatory effects of Ang II + ddAVP on renin synthesis in mpkccdc14 cell line, a mouse cortical line composed only by CD principal cells. Tolvaptan (V2R antagonist) reduced the additive effect of Ang II + ddAVP on renin expression. To achieve in vivo relevance we further measured renin mRNA levels in renal inner medullary tissues from mice subjected to 16 hours of water deprivation and controls. Mice water-deprived showed significantly greater renin mRNA levels in the renal inner medulla than controls. These results indicate that the activation of V2R stimulates renin mRNA synthesis and prorenin secretion in M-1 cells via cAMP/PKA/CREB pathway.
Abstract 482: Transgenic Mice Containing Haplotype-I Of Human Angiotensin Receptor Type-1 Gene Are Susceptible To Stroke
Authors: Jain Sudhir , Tulsulkar Jatin , Rana Anita , Shah Zahoor , Kumar Ashok
Published: July 2021

Hypertension is one of the co-morbid conditions for, and profoundly increases the incidence of stroke in humans. Hypertension is polygenic in nature and its familial inheritance is regulated by single nucleotide polymorphisms (SNPs) in the genes associated with renin angiotensin aldosterone system (RAAS). Angiotensin II (AngII) is shown to be at the center stage in driving the RAAS via activation of angiotensin 1 receptor (AT
1
R). This makes AT
1
R gene one of the prime candidates whose differential regulation leads to the predisposition to disorders associated with hypertension. A haplotype block of four SNPs is represented primarily by haplotype-I, or Hap-I (TTAA), and haplotype-II, or Hap-II (AGCG), in the promoter of human AT
1
R (hAT
1
R) gene. To better understand the physiological role of these haplotypes, transgenic (TG) mice containing haplotype-I and II of the hAT
1
R gene in a 166Kb BAC (bacterial artificial chromosome) were generated. Our results show that 8 weeks old male transgenic mice containing Hap-I have increased brain hAT1R expression (6.5 fold) and have increased systolic blood pressure (11mmHg) as compared to the mice with Hap-II. Also, the results post PMCAO (permanent middle cerebral artery occlusion) suggest that the mice containing Hap-I suffered from significantly higher (p<0.05) neurological deficits (30% higher than Hap-II) and larger brain infarcts (26% larger than Hap-II). Similarly the molecular analysis of oxidant/inflammatory markers post PMCAO show a significant increase (p<0.05) in NOX-1 (1.85 fold up), CRP (9 fold up) and IL6 (2.8 fold up) and a corresponding reduced expression of antioxidants SOD (60% down) and HO-1 (55% down) in Hap-I mice as compared to Hap-II mice. These results suggest that increased expression of hAT
1
R leads to the damage associated with endothelial dysfunction and vascular remodeling, eventually rendering Hap-I TG mice susceptible to stroke related pathology.
Abstract 485: An Urologic-nephrologic Based Approach to Resistant Hypertension: Early Clinical Experience with a Non-vascular Treatment
Authors: Heuser Richard , Buena Terry , Cooper Randy , Gold Adam , Rao Rahul , Van Alstine William , Desai Mihir
Published: July 2021

The Symplicity HTN-3 recently failed to meet its primary efficacy endpoint in blood pressure reduction. The natural orifice denervation system developed by Verve Medical directs radiofrequency energy to the renal pelvic space where the preponderance of afferent nerves originate. We have previously demonstrated the feasibility of the Verve Medical NephroBlate to ablate these nerves. We developed a protocol to treat a small number of patients (n=3, 4 kidneys) undergoing elective nephrectomy at Muljibhai Patel Urological Hospital on Nadiad, India. We treated three patients with end stage kidney disease prior to explants of the affected diseased kidney. One patient was pre-renal transplant and had both kidneys treated. One week after fluoroscopically aided transurethral treatment with the NephroBlate™ device, the previously planned nephrectomy was performed. Procedure time was between 9 to 15 minutes and no adverse effects were recorded. The histopathological results in all cases showed a significant destruction of the peri-pelvic nerves from the renal pelvic space to the serosa (1.75mm). With a significant elimination of most of the afferent and efferent nerves in the treated area(approximately 1cm), and no change to the adjacent nerves in the control segments in the histopathologic specimens, as well as a safe and painless procedure for the patients, we proceeded with our clinical studies on resistant hypertensive patients. As in the diseased kidney study, the procedures were done under general anesthesia. Within 30 seconds of treatment of the first kidney, a blood pressure response was noted (reduction of mean systolic blood pressure 44mmHg, reduction of mean diastolic blood pressure 13mmHg). Following the procedure, none of the patients had significant pain or bleeding. At one month follow-up, the patients continue to be normotensive with no renal issues. This very small series did not exclude any patients with renal disease and no patients received any anticoagulants. The blood pressure response was immediate and occurred while the patients were under general anesthesia. In this small series of humans treated with limited follow-up, we see a promising nonvascular alternative for renal denervation for treatment for resistant hypertension.
Abstract 504: Cardiac Safety Profile of Etamicastat, a Novel Peripheral Selective Dopamine-ß-Hydroxylase Inhibitor, in the Dog
Authors: Pires Nuno M , Igreja Bruno , Loureiro Ana I , Lacroix Pierre , Soares-da-Silva Patricio
Published: July 2021

Etamicastat, a peripheral reversible dopamine-ß-hydroxylase inhibitor, blocked the hERG current amplitude with an IC50 value of 35.4 μg/ml in HEK 293 cells. At 0.3 and 3 μg/ml, etamicastat had no effects on the action potential (AP) in dog Purkinje fibers. At 30 μg/ml, etamicastat significantly affected resting membrane potential (+4%), AP amplitude (-4%), AP duration at 60% (-14%) and AP duration at 90% (+5%) repolarization, and AP triangulation (+79%). In the telemetered conscious dog, etamicastat (up to 20 mg/kg) had no effects on arterial blood pressure, heart rate and the PR interval. At 10 and 20 mg/kg, the QTc interval was slightly prolonged (8 to 9% max, P < 0.05). No arrhythmia or other changes in the morphology of the ECG were observed. The maximum observed plasma concentrations (Cmax) of etamicastat (i.e. 3h post administration) were 1.4 and 3.7 μg/ml at 10 and 20 mg/kg, respectively. No deleterious effects, including ECG disturbance were observed in male and female dogs dosed by gavage with etamicastat (up to 20 mg/kg/day) for 28 days. Mean plasma Cmax etamicastat levels ranged between 2.4 and 6.3 μg/ml on Day 1 and Day 28 of treatment, respectively. It is concluded that the blockade of the delayed rectifier potassium channels by etamicastat together with the QTc interval prolongation observed in conscious dogs can be considered as modest with respect to the measured plasmatic concentrations. These findings suggest that etamicastat is not likely to prolong the QT interval at therapeutic doses (~ 0.2 μg/ml).
Abstract 507: Dual AT1 Receptor/Neprilysin (NEP) Inhibition (ARNI) vs. AT1 Receptor Blockade in TGR(mRen2)27 Rats: The More NEP Inhibition The Better?
Authors: Roksnoer Lodi C , van Esch Joep H , van Veghel Richard , Garrelds Ingrid M , Bhaggoe Usha M , Friesema Edith C , Leijten Frank P , Danser Alexander H , Batenburg Wendy W
Published: July 2021

Objective:
Neprilysin inhibitors (NEPi) prevent the breakdown of natriuretic peptides, promoting vasodilation and natriuresis. However, they also increase angiotensin and endothelin-1 (ET1). This study compared the combination of an AT1 receptor antagonist (irbesartan, IRB) ± a low or a high dose of the NEPi thiorphan in renin-overexpressing, hypertensive TGR(mREN2)27 rats.

Methods:
TGR(mREN2)27 rats were treated for three weeks with vehicle, IRB (15 mg/kg.day) or IRB + thiorphan (0.1 or 1.0 mg/kg.day; TH0.1 and TH1.0). Hemodynamics were evaluated by telemetry, and vascular reactivity was determined in isolated mesenteric arteries (Mulvany myograph).

Results:
Baseline mean arterial blood pressure (MAP) was 168±3 mmHg. All treatments lowered MAP by ≈50 mmHg around day 4. After 7 days, MAP started to increase during treatment with IRB or IRB+TH1.0 (to 141±10 mmHg and 133±10 mmHg, respectively, on day 21), while MAP in rats treated with IRB+TH0.1 remained low at 104±5 mmHg on day 21. Heart weight/body weight ratio, cardiac ANP expression and myocyte size decreased only in the IRB+TH0.1 group. Plasma ET1 was increased only by TH1.0 versus IRB alone, and this increase was accompanied by an increase in renal sodium-hydrogen exchanger 3 (NHE3) protein

expression:
ET1-induced constriction was reduced by IRB+TH0.1 only. Vascular ET
B
R expression levels and studies with the ET1 type B receptor (ET
B
R) antagonist BQ788 revealed that this reduction was most likely due to ET
B
R upregulation.

Conclusion:
TH0.1 enhanced the blood pressure-lowering effects of irbesartan and diminished cardiac hypertrophy. Higher doses of thiorphan resulted in significant ET1 rises and renal NHE3 upregulation, thereby increasing blood pressure and sodium reabsorption. The simultaneously occurring upregulation of vasodilatory ET
B
R was insufficient to overcome this effect. Clearly therefore, too much NEPi on top of AT1 receptor antagonism might be harmful.
Abstract 511: Influence Of Aerobic Exercise Training On Steroid Hormones And Cardiovascular Biomarkers In Hypertensive Postmenopausal Women
Authors: Novais Iane P , Puga Guilherme M , Jarrete Aline P , Nunes Hygor A , Delbin Maria A , Zanesco Angelina
Published: July 2021

Evidences have shown that postmenopausal women are at increased risk of cardiovascular complications as compared with premenopausal, but the insight mechanisms are not fully understood. On the other hand, no studies have examined the interaction between endocrine and cardiovascular biomarkers in trained postmenopausal women. The aim of this study is to evaluate steroids hormones and cardiovascular biomarkers in trained hypertensive (HT) postmenopausal women at basal condition or submitted to acute challenges of L-arginine, placebo or a bout of exercise.

Methods:
Twenty-two women underwent to ET on treadmill, 3 days/week, 40 min, for 24 sessions, at moderate intensity. Volunteers were randomized into three groups, where an acute administration of L-arginine (9g) was given (ARG group), a challenge of a bout of aerobic exercise (30 min) was applied with placebo pills (EXE group) or the combination of the both challenges (ARG-EXE group). The challenges were applied before and after ET. Office blood pressure (BP) and ambulatory blood pressure monitoring (ABPM) were evaluated. Biochemical analyses measuring nitrite/nitrate (NOx), cGMP, total testosterone, cortisol levels and redox state were examined during the challenges and after overnight fasting, before and after ET. Effect of ET: Reduction in body mass index was found after ET whereas no changes were observed in the officce BD or ABPM. Similarly, testoterone, cortisol, NOx- and MDA levels as well as in catalase activity wre not altered. An increase in the cGMP concentration (basal: 5.0 ± 0.4 and ET: 6.3 ± 0.7 pmol/mL) and SOD activity (basal: 15.6 ± 2 and ET: 28.1 ± 1.6 u/mL) were observed after ET. Effect of challenges: Reduction in SBP (-14 mmHg) and DBP (-12 mmHg) values were observed in ARG-EXE group in office measurements. In both challenge groups (EXE and ARG-EXE), a significant increase in NOx- levels (EXE: 57% and ARG-EXE: 65%) as well as cGMP concentration (EXE: 19% and ARG-EXE: 37%) were found. Cortisol levels were significantly reduced in EXE (-21%) and ARG-EXE (-24%) groups.

Conclusion:
A reduction in BP that was accompanied by increased activation of the NO/cGMP pathway and a decrease in cortisol levels in trained HT women.
Abstract 518: Loss of Caveolin-1 in Mouse, Rat and Human Proximal Tubule Cells Increases GRK4 Activity and Decreases D1-Like Receptor Cell Surface Levels
Authors: Gildea John J , Bigler Wang Dora , Van Sciver Robert E , Felder Robin A
Published: July 2021

Normal dopaminergic signaling in the renal proximal tubule under conditions of sodium loading leads to natriuresis without the need to increase blood pressure. Low caveolin-1 (CAV1) expression in the kidney is associated with dopaminergic signaling defects and salt sensitive hypertension in both mice and rats. We and others have shown that SNPs in human CAV1 are associated with hypertension. We hypothesize that low CAV1 expression causes increased GRK4 kinase activity due to lack of physical interaction and inhibition of GRK4; thus overactive GRK4 would inactivate the dopamine-1 receptor (D
1
R). We have previously shown that CAV1 reduction, knockdown or knockout in mouse, rat and human renal proximal tubule cells (RPTC) leads to decreased dopamine D
1
-like receptor binding at the proximal tubule cell surface and that re-expression of CAV1 alpha isoform is necessary to rescue this dopaminergic defect. Here we extend those studies by showing that defects in D
1
R cell surface expression due to low CAV1 expression can also be rescued by inhibiting GRK4 in human RPTC using GRK4 siRNA or by introducing heparin (1 μmol/L, 24 hrs) in mouse and rat RPTC. GRK4 siRNA lowered GRK4 expression by greater than 80% in all four human RPTC cell lines and partially restored fluorescent D
1
-like receptor antagonist bodipy630 SKF83566 cell surface binding (scrambled siRNA 66,231±7,286 RFU, GRK4 siRNA 96,206±11,035 RFU, P<0.05, N=28). In RPTC from CAV1 knockout mice, electroporation of heparin restored bodipy630 SKF83566 cell surface binding (vehicle 21,346±3,219 RFU, heparin 58,380±8,032 RFU, P<0.05, N=7). In rat SHR RPTC, CAV1 expression is very low, and the stable transfection of CAV1 partially restored their D
1
-like receptor surface expression. Electroporation of heparin in these CAV1 transfected cells (SHR CAV1) restored bodipy630 SKF83566 cell surface binding back to levels found in WKY RPTC (SHR CAV1 35,241±4,280 RFU, SHR CAV1 heparin 54,218±6,564 RFU, WKY 56,821± 3,546 RFU, P<0.05, N=7). In summary, we show that dopamine D
1
-like receptor defects caused by loss of CAV1 are likely due to increased GRK4 activity and can be restored by either increasing CAV1 expression or decreasing GRK4 expression.