bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sexual Dimorphic Responses of Renal Transporters to High Salt Diet Favor More Diuresis in Females
Authors: Veiras Luciana Cecilia , Lisboa Hector , Khalil Zoya , Ralph Donna Lee , McDonough Alicia Ann 
Published: November 2023

We previously reported, in male rats, that high salt diet (HSD) increased proximal tubule (PT) Na+/H+ exchanger phosphorylation (NHE3pS552), a marker of its inactivation, depressed total abundance of distal tubule Na+‐Cl− cotransporter (NCC), and redistributed apical Na+ transporters to higher density fractions (Yang LE, AJP Renal, 2008). Female rats and mice have lower abundance of proximal tubule sodium transporters (NHE3, NaPi2) and higher abundance and phosphorylation (activation) of NCC as well as cleaved (activated) epithelial sodium channels' (ENaC) α and g subunits (FASEB J, 2016, 30: Supp 967.29). Female mice also have a more robust pressure natriuretic response than males (Mirabito KM et al, AJP Renal, 2014). Based on this background, this study aimed to compare the responses of females (F) and males (M) to high salt diet; we postulated that F would exhibit more robust responses than M.MethodsC57Bl/6 mice (n=5/group) received normal salt diet (0.26% NaCl; MNS: males normal salt; FNS: females normal salt) or a high salt diet (4.0% NaCl; MHS: males high salt; FHS: females high salt) for two weeks. Transporter and channel abundance were determined by quantitative immunoblot in homogenates of renal cortex. The Figure displays the fold change in the abundance of transporters and channels after HSD, relative to NSD in F and M.ResultsFemales had a greater diuretic response to HSD (6 fold) than M (ns). At baseline, F had lower PT NHE3 (0.6‐fold) and lower NHE3pS552 (0.7‐fold) than M. NHE3pS552 increased 0.2‐fold in MHS, and was unchanged in FHS. Along the loop and distal nephron, there was no significant difference in Na+‐K+‐2Cl− cotransporter isoform 2 (NKCC2), NKCC2pT96T101, NCC, or NCCpS71 at baseline, yet SPAK, a regulatory kinase that phosphorylates these cotransporters and claudin 7 were elevated in F (0.5‐ and 0.7‐fold, respectively). In FHS NKCC2, NKCC2pT96T101, NCC, and NCCpS71 were lower than FNS (0.2‐, 0.5‐, 0.3‐, 0.5‐fold, respectively) and in MHS vs. MNS only NCC decreased (0.2‐fold) suggesting less Na+ reabsorption in this nephron region in F vs. M. In collecting duct at baseline, ENaC γ was higher in F than M (0.15‐fold) and doubled in both FHS and MHS vs. NS. ENaC γ subunit cleavage decreased 0.2‐fold only in MHS. Taken together, these results demonstrate that the responses to HS diet are sex dependent. The more robust diuresis in FHS can be attributed to lower PT NHE3 at baseline as well as reduced NKCC2, NKCC2pT96T101, NCC and NCCpS71 during HS diet. These characteristics likely facilitate pressure natriuresis and contribute to lower blood pressures in females.Support or Funding InformationNIH R01DK 083785, AHA 15GRNT23160003
Sex Dependent Effects of Prenatal Nicotine Exposure on Cardiovascular Reactivity: Are Males at a Greater Risk for Cardiovascular Disease?
Authors: Hayward Linda F , Watkins Jacqueline 
Published: November 2023

Prenatal nicotine exposure (PNE) has been linked to an increased incidence of anxiety‐disorders, risk of nicotine use, and dysregulation of the hypothalamic orexin system. Recent data link dysregulation of the orexin system to cardiovascular disease. The aim of this study was to evaluate cardiovascular reactivity of adult offspring exposed to nicotine in utero and correlate differences with changes in orexin system gene expression in the hypothalamus and amygdala. Pregnant Sprague Dawley rats had an osmotic mini‐pump filled with nicotine implanted on day 6 of pregnancy (exposure dose 3 mg/kg). At 12 weeks of age (n=4–6/group) offspring were instrumented with arterial catheters and tested 2 days later. PNE male and female weighed ~20% more than controls (P<0.05) but resting mean arterial pressure (MAP) was not significantly different between groups. After an acute dose of nicotine (0.37mg/kg), MAP increased ~ 9 mm Hg in females and 6 mm Hg in male within 2 min. of a subcutaneous (sc) injection, independent of prenatal treatment At 18 minutes' post nicotine injection, MAP in both male and female controls and PNE females decreased significantly below baseline (−9 mmHg) while the MAP of PNE males returned to baseline. There was a strong trend (P<0.07) for the pressor response to angiotensin II (10 microg/kg) to be greater in the PNE males compared to control but not for the PNE females when compared to sex‐matched controls. In the hypothalamus orexin‐type 1 receptor gene expression was increased significantly in PNE males compared to controls (P<0.006). Alternatively, in the amygdala a decrease in orexin‐type 2 receptors in PNE females compared to controls (P<0.03) was identified These results suggest that male offspring exposed to nicotine in utero may be more susceptible to the negative cardiovascular consequences of nicotine when compared to females due to sex‐dependent changes in orexin‐receptor gene expression in the brain.Support or Funding InformationFlorida Department of Health‐James and Esther King Biomedical Research Program
Time Course of Changes in Calf Venous Compliance during Pregnancy and Postpartum in Humans
Authors: Parker Rosemary , Yoo Jeungki , Jarvis Sara , Okada Yoshiyuki , Best Stuart , Stickford Abigail , Levine Benjamin , Fu Qi 
Published: November 2023

BackgroundPregnancy is associated with dramatic changes in volume status and vascular function. Previous human studies have focused extensively on endothelial function and arterial stiffness in pregnancy, but time‐course changes in venous compliance throughout gestation have received little attention.PurposeTo examine the changes in calf venous compliance before, during and after pregnancy.Methods17 healthy normotensive women aged 31 ± 5 (mean ± SD) years completed all longitudinal studies including pre‐pregnancy (mid‐luteal phase of the menstrual cycle), early‐pregnancy (4–8 weeks gestation), late‐pregnancy (32–36 weeks gestation), and postpartum testing (6–10 weeks post‐delivery). Subjects were in the supine (rotated about 15° into the left lateral) position, and venous occlusion plethysmography with strain gauges was used to measure calf venous compliance in the right leg. Brachial blood pressure (BP, SunTech) and heart rate (HR, lead II of electrocardiogram) were also measured on each testing day.ResultsThe changes in calf venous compliance between pre, early, and late pregnancy (0.05 ± 0.01, 0.06 ± 0.01, and 0.05 ± 0.01 ml/100 ml/min, respectively) appears to be relatively stable. However, there was a significant decrease in calf venous compliance post pregnancy (0.04 ± 0.01 ml/100 ml/min, ANOVA p<0.05) as compared to during pregnancy. Resting systolic BP was significantly lower during early pregnancy as compared to pre and late pregnancy (101±7 vs. 107±8 and 108±7 mmHg, respectively; p<0.05) but not different from post pregnancy (103±7 mmHg). Resting diastolic BP during early pregnancy (59±4 mmHg) had a tendency to differ from pre (63±3 mmHg, p=0.081) and post pregnancy (64±6 mmHg, p=0.072). HR, however, decreased significantly during postpartum (58±9 bpm, ANOVA p<0.001) as compared to pre, early, and late pregnancy (74±13, 69±11, 78±12 bpm respectively).ConclusionDespite blood volume expansion and a fall in systemic vascular tone during pregnancy, venous compliance remains relatively stable throughout the entire gestation. The decrease in venous compliance during postpartum may be related to the hormone oxytocin, as approximately 90% of the women were lactating after delivery.Support or Funding InformationNIH R21 grant (HL088184)AHA Grant‐in‐Aid (13GRNT16990064)The Harry S. Moss Heart Foundation
TNFα and IL‐17 downregulates βENaC expression and reduces migration in vascular smooth muscle cells
Authors: Duncan Jeremy W. , Warrington J. Paula , Ryan Michael J. , Granger Joey P. , Drummond Heather A. 
Published: November 2023

Studies from our laboratories have shown that beta Epithelial Na+ Channel protein (βENaC) mediates vascular smooth muscle cell (VSMC) and cytotrophoblast cell migration. Inflammatory cytokines have also been shown to play a role in VSMC and trophoblast migration. However, whether cytokines regulate βENaC protein expression has never been determined. Therefore, the purpose of this study was to determine if the cytokines, Tumor Necrosis Factor‐alpha (TNFα) and Interleukin‐17 (IL‐17), alter expression of βENaC and migration in VSMCs. To address this, cultured VSMCs (A10; rat) were treated with recombinant TNFα or IL‐17 (0 – 100 ng/mL). βENaC expression was assessed after 16 hours using Western blotting. Cellular migration responses were assessed at 24 and 48 hours using a scratch wound assay. TNFα inhibited the expression of βENaC in VSMCs by 51% (49.3 ± 9.6 vs 100 ± 0; p= 0.006) and 59% (40.7 ± 12.8 vs 100 ± 0; p= 0.01) at 50 and 100 ng concentrations vs control cells, respectively. TNFα (50 ng) impaired wound healing compared to control cells at 24 hr (89 ± 7.8% vs 58 ± 4.8%) and 48 hr (84 ± 8.2% vs 34 ± 9.7%) following injury, as measured as a percentage of initial wound area (p < 0.05). This effect persisted at 100 ng, where TNFα abolished wound healing at 24 hr (100 ± 12% vs 58 ± 4.8%) and 48 hr (93 ± 17% vs 34 ± 9.7%) vs control cells (p< 0.05). IL‐17 also significantly reduced βENaC by 30% (100ng vs Control; 70.1 ± 10.6 vs 100 ± 0; p= 0.037). Similarly, IL‐17 (100 ng) impaired wound healing at 24 hr (85 ± 7.4% vs 62 ± 2.4%) and 48 hr (83 ± 8.3% vs 45 ± 5.2%) compared to control cells (p< 0.05). These data indicate that the inflammatory cytokines TNFα and IL‐17 reduce βENaC protein expression and cell migration in VSMCs. Whether TNFα and IL‐17 attenuate βENaC expression in cytrotrophoblasts or attenuate migration through βENaC inhibition remains to be determined. These findings suggest VSMC and cytotrophoblast migration may be compromised in conditions of high circulating levels of cytokines, such as pre‐eclampsia. Further studies to determine the molecular mechanisms, as well as potential approaches to rescue βENaC could be beneficial in certain pathophysiological cases where appropriate cell migration is critical.Support or Funding InformationThis study was supported by a National Institutes of Health Grant, HLHL51971, and an NRSA Institutional Training Grant, T32HL105324.
Effect of Maternal Antioxidant MitoQ Treatment on Offspring Cardiovascular Function in a Rat Model of Intrauterine Growth Restriction (IUGR)
Authors: Aljunaidy Mais M , Morton Jude S , Kirschenman Raven , Case Patrick , Cooke Christy‐Lynn , Davidge Sandra T 
Published: November 2023

IntroductionA suboptimal environment in fetal life is linked to cardiovascular disease in adult life. Maternal hypoxia can lead to placental oxidative stress, which is associated with abnormal cardiovascular function in the offspring. We hypothesize that maternal treatment with MitoQ, a mitochondrial antioxidant, may prevent the development of cardiovascular disease in adult offspring.MethodsPregnant rats were injected with either MitoQ loaded nanoparticles (nMitoQ; 125 μM‐nanoparticles prevent MitoQ from crossing to the fetus) or saline via tail vein on gestational day (GD) 15. Rats then were subdivided into two groups exposed to either hypoxia (11% O2) or normoxia (21% O2) from GD 15–21 (term; 22 days). At 7 months of age, blood pressure (tail‐cuff plethysmography), in vivo cardiac function (echocardiography) and ex vivo cardiac susceptibility to ischemia‐reperfusion (I/R) injury were assessed in both male and female offspring. A 2‐way ANOVA was used for analyses.ResultsHypoxia led to diastolic dysfunction in male offspring (P<0.05) and tended to cause diastolic dysfunction in female offspring (P=0.07). nMitoQ treatment improved diastolic function in only female offspring in both normoxic and hypoxic groups [mitral valve E wave velocity/A wave velocity (MV E/A): normoxia + saline: 1.52±0.10 vs. normoxia + nMitoQ: 1.23±0.09 and hypoxia + saline: 2.18±0.40 vs. hypoxia + nMitoQ: 1.29±0.08, P<0.01]. In male offspring only, hypoxia reduced the pulmonary valve peak velocity (PV Peak Vel) and nMitoQ treatment ameliorated this effect (PV Peak Vel: hypoxia + saline 620±28 mmHg vs. hypoxia + nMitoQ 781±53 mmHg, P<0.05). Neither hypoxia nor nMitoQ altered blood pressure and cardiac susceptibility to I/R injury.ConclusionnMitoQ treatment in mid gestation restored PV Peak Vel in hypoxic male offspring. In female offspring, maternal treatment with nMitoQ improved diastolic function in both normoxic and hypoxic animals. This study suggests that maternal/placental treatment can alter cardiovascular function of offspring later in life.Support or Funding InformationCIHR, WCHRI, SCHF and RAHF
The Androgen Receptor Contributes to Hypertension in Ovariectomized IUGR but Not in Ovariectomized Control Rats
Authors: Davis Gwendolyn K. , Newsome Ashley D. , Alexander Barbara T. 
Published: November 2023

The prevalence of hypertension (HTN) is two‐fold higher in low birth weight (LBW) women at age 60 relative to normal birth weight (NBW) counterparts. Yet, the mechanisms that contribute to greater cardiovascular risk (CVR) in LBW women are unknown. Previous studies from our laboratory demonstrate that intrauterine growth restriction (IUGR) programs persistent estrus and a significant increase in circulating testosterone (T) and blood pressure (BP) in female Sprague Dawley (SD) IUGR rats at 12 months of age. Androgen receptor (AR) blockade abolishes HTN in female IUGR at 12 months of age indicating a role for the AR in the etiology of age‐dependent HTN in female IUGR. We previously reported that ovariectomy (OVX) at 10 weeks of age has no effect on BP or T levels in NBW (control) SD rats at 4 months of age. However, OVX at 10 months of age induces a significant increase in BP and T in SD controls compared to intact SD controls by 12 months of age. However, the importance of T in OVX‐induced HTN, a model of menopausal HTN, is not known. We tested the hypothesis that OVX‐induced HTN in female SD rats in later life is T dependent. Rats underwent sham (intact) or OVX at 10 months of age followed by vehicle or flutamide, an AR antagonist (8mg/kg/day, SC at 12 months of age for two weeks). Total fat and lean mass were measured via Echo MRI pre‐OVX and after treatment (Paired T‐test). BP was measured in conscious, chronically catheterized rats following treatment (2way ANOVA; Tukey's multiple comparison). BP was increased in vehicle OVX control relative to vehicle intact control (137±3 vs.129±3 mmHg, respectively). However, BP did not differ upon comparison of flutamide OVX control versus vehicle OVX control (140±7 mmHg) suggesting that OVX‐induced increase in BP in control rats does not involve a role for the AR. As observed previously, BP was not further elevated by OVX in IUGR. Furthermore, BP was decreased by 19 mmHg in flutamide intact IUGR relative to vehicle intact IUGR. Yet, BP was decreased by only 10 mmHg in flutamide OVX IUGR versus vehicle OVX IUGR suggesting that the importance of the AR in BP control may differ in ovarian intact IUGR versus ovarian deficient IUGR. OVX induced an increase in total fat mass, but attenuation of the OVX‐induced increase in total fat mass by flutamide was specific to IUGR (Table). Therefore, this study indicates that the AR contributes to enhanced CVR in female IUGR regardless of ovarian status, but not in OVX control SD rats.Support or Funding InformationNIH: T32HL105324‐07, HL074927, HL51971, P20GM104357; AHA: GRNT19900004.

Total Fat Mass (grams):
Pre‐OVX
Post‐Treatment

Control Vehicle
26±2
62±4*

Control Flutamide
34±7
60±10*

IUGR Vehicle
27±10
53±12*

IUGR Flutamide
22±3
35±8

P<0.05 vs Pre‐OVX.
Chronic Central Leptin Infusion Improves Cardiac Function in Diabetic Rats With Heart Failure
Authors: da Silva Alexandre A. , Gava Fábio N. , Lataro Renata M. , Silva Carlos Alberto A. , Rodrigues Driéli P. , Guida Tamires , do Carmo Jussara M. , Salgado Hélio C. 
Published: November 2023

Myocardial infarction (MI) is a major cause of mortality and morbity and the leading cause of heart failure (HF) worldwide. We previously demonstrated that leptin, a peptide hormone produced by adipocytes, exerts powerful antidiabetic effects via activation of its receptors in the central nervous system (CNS). We also showed that chronic central leptin infusion restores intrinsic heart rate, cardiac sympathetic‐vagal balance and baroreflex sensitivity in uncontrolled diabetes. Therefore, in this study we examined if chronic intracerebroventricular infusion of leptin improves cardiac function in rats with HF induced by MI. Wistar Munich rats (275–300 g, n=4–5/group) were submitted to MI by ligation of the left descending coronary artery. Diabetes was induced one week later by a single injection of streptozotocin (STZ, 35 mg/kg, i.p.). Seven days later, rats were instrumented with an intracerebroventricular (ICV) cannula into the lateral ventricle for continuous infusion of leptin (0.62 μg/h, 0.5 μL/h, n=5) or vehicle (0.5 μL/h, n=4), for 4 weeks using osmotic pumps (Alzet, model 2002). Cardiac function was evaluated 6 days after MI surgery and on days 14 and 28 of ICV leptin or vehicle infusion using the echocardiograph VEVO 2100 (VisualSonics, Canada). STZ caused severe hyperglycemia in both groups (ranging from 472±17 to 477±14 mg/dl) which was completely normalized by chronic ICV leptin infusion (120±8 mg/dl). Compared to vehicle group, leptin infusion for 4 weeks also markedly ameliorated cardiac function as evidenced by lower left atrium/aorta ratio (1.73±0.07 vs. 2.63±0.23 mm) and higher cardiac output (113.8±27.6 vs. 69.5±10.0 ml/min) and ejection fraction (36.7±2.3 vs. 30.7±8.7 %). These results suggest that in addition to its powerful CNS‐mediated antidiabetic effects, leptin attenuates the progression of HF after MI in diabetic rats by improving cardiac function.Support or Funding InformationNHLBI‐PO1HL51971, NIGMS‐P20GM104357, FAPESP, CNPq
A role for Sweet Taste Receptors (T1R2/T1R3) in fructose‐induced increase in NKCC2 Phosphorylation in thick ascending limbs (TALs)
Authors: Kassem Kamal M , Ares Gustavo , Ortiz Pablo 
Published: November 2023

High fructose consumption has been implicated in hypertension, renal damage and metabolic syndrome in humans. We previously showed that a fructose‐enriched diet does not increase blood pressure in rats unless it is combined with high salt intake. This effect was accompanied by a large increase in phosphorylation of the renal Na/K/2Cl cotransporter NKCC2 at threonine 96/101. The mechanisms by which fructose induces salt‐sensitive hypertension are not clear. In a proteomics screen, we found that the sweet taste receptor T1R2 was present in TALs. Others reported mRNA expression of T1R2 and T1R3 in whole kidney homogenates. Both T1R2 and T1R3 are required to initiate signaling by sweet agonists such as fructose. Unlike glucose, fructose is not fully reabsorbed in the proximal tubule, thus it is possible that activation of sweet taste receptors induce signaling leading to NKCC2 phosphorylation. We hypothesize that a fructose‐enriched diet (20% fructose in drinking water) stimulates NKCC2 phosphorylation in part by acting on sweet taste receptors (T1R2/T1R3). To test this, we used C57 wild‐type mice (WT) and mice on the C57 background with dual deletion of T1R2 and T1R3 (T1R2/T1R3 KO). Mice were given tap water or 20% fructose in drinking water for 7–8 days. TAL suspensions from WT and T1R2/T1R3 KO mice were obtained to measure total NKCC2 expression, GAPDH (loading control) and NKCC2 phosphorylation at Thre96/101 by Western blot. In WT mice, fructose in drinking water increased phosphorylated NKCC2 by 248 ± 82% (n=5, p<0.01), whereas it decreased total NKCC2 expression by 38 ± 18% (p<0.05). In contrast, in TALs from T1R2/T1R3 KO mice, fructose in drinking water did not affect phosphorylated NKCC2 (PNKCC2/total NKCC2: − 16 ± 28%, p=0.88). We conclude that 1‐week of a fructose‐enriched diet enhances NKCC2 phosphorylation in the mouse TAL, and this effect is in part due to sweet taste receptors T1R2/T1R3. Hence, our data shows for the first time that sweet taste receptors T1R2 and T1R3 play a role in regulating renal transporters. These receptors could play a role in the deleterious effects of fructose intake in the kidney.Support or Funding InformationNIH‐NIDDKAHA
Central Angiotensin II Modulation of Hypoxia‐Inducible Factor (HIF)‐1 Alpha in the PVN: Possible Mechanism for Sympathetic Activation
Authors: Haibara Andrea , Sharma Neeru , Zheng Hong , Liu Xuefei , Patel Kaushik P 
Published: November 2023

Upregulation of Angiotensin II (Ang II) in the paraventricular nucleus (PVN) of the hypothalamus has been associated with the increased sympathetic outflow observed in chronic heart failure (CHF). Recently, we have shown the contribution of HIF‐1α in augmentation of the NMDA‐NR1 mediated sympathoexcitatory responses from the PVN in CHF. HIF‐1α silencing in the PVN normalizes the increased renal sympathetic nerve activity observed in rats with CHF. However, the mechanism of increased expression of HIF‐1α remains unclear. In the present study, we evaluated whether the chronic increase in Ang II levels in the brain could cause augmentation of the HIF‐1α expression in the PVN which in turn may contribute to the sympathoexcitation. Sprague‐Dawley rats (250–300 g) were subjected to 14 days of ICV infusion of Ang II (20 ng/min) or 0.9% sterile saline (0.5μl/h) through osmotic mini‐pumps. Ang II infusion increased baseline mean arterial pressure (84 ± 4 vs. 126 ± 9 mmHg), increased baseline renal sympathetic nerve activity (6.4 ± 1.9 vs. 20.5 ± 2.3 % of Max), increased cardiac sympathetic tone (75 ± 6 vs. 96 ± 7 bpm) and decreased cardiac parasympathetic tone (36 ± 3 vs. 16 ± 2 bpm) compared to saline. The Ang II‐infused group also showed an impairment of baroreflex control of heart rate (1.5 ± 0.3 vs. 0.5 ± 0.1 ms/mmHg), a potentiation of the pressor chemoreflex response (30 ± 7 vs. 53 ± 7 mmHg) and increased sympathoexcitation induced by NMDA (200 pmol) microinjected into the PVN (23 ± 4 vs. 73 ± 16 %). Concomitantly, Ang II infusion increased the expression of HIF‐1α mRNA (2.79 fold) and protein l(1.54 fold) and also the expression of NMDA‐type1 (NR1) receptors mRNA (3.17 fold) and protein (1.52 fold) in the PVN. In contrast, the Ang II treatment failed to induce any significant changes in mRNA expression of HIF‐1α and NR1 receptors in the cerebral cortex. Taken together, our studies suggest that increased central levels of Ang II contribute to the regulation of HIF‐1α expression in the PVN, which may be involved in the potentiation of glutamatergic activation of pre‐autonomic neurons in the PVN, suggesting a relationship between Ang II, HIF‐1α, and sympathoexcitation.Support or Funding InformationSupported by CNPq‐Brazil 234520/2014‐0 and NIH grants HL124104 & HL62222.