bluuebunny/crossref_metadata_2025 huggingface dataset:
Sex Dimorphism of Systolic Blood Pressure and Proteinuria during High Salt Intake in Ang II‐dependent Hypertension
Authors: Planchard Jeffrey A , Lowenburg Benjamin M , Martin Victoria L , Botros Fady T , Prieto Minolfa C
Published: June 2021

Salt intake inhibits the renin angiotensin system (RAS), but when angiotensin II (AngII) levels are not suppressed, increased salt intake exacerbates hypertension and renal injury. We determined whether the pressor response to AngII and associated kidney injury exhibit sex differences during high salt (HS) intake and endogenous RAS blockade. In this study, 35 Sprague‐Dawley rats: [1) Sham+HS [male n=5; female n=4]; 2) AngII [male n=3; female n=3] 3) AngII+HS [male n=5; female n=5]; 4) AngII+HS+LOS [male n=5; female n=5], were infused with AngII (80ng/min; 14 days), fed with HS diet (8% NaCl), and treated with losartan (LOS, 30 mg/L). Systolic blood pressure (SBP) baseline was not different between males and females (116±3 vs.119±2 mmHg) or after 2‐weeks of AngII infusions (228±9vs.217±20 mmHg). Addition of HS diet did not modify the SBP (228±13 vs.211±16 mmHg). LOS similarly ameliorated the increases in SBP in both genders (156±15 vs.157±10 mmHg). HS intake increased proteinuria in AngII‐infused rats (48±5vs.19±6 mg/day) and augmented progressively with a greater increase in males than females (79±6 vs.47±6 mg/day). The proteinuria in female rats was ameliorated by LOS. Salt sensitivity of SBP does not exhibit sexual dimorphism, however the augmented proteinuria in male rats may reflect a greater degree of renal injury than in female rats.

Support from Tulane‐BIRCWH and Merck & Co., Inc.
An increase in renal sympathetic nerve activity (RSNA) is evoked by γ‐melanocyte stimulating hormone (γMSH) infusion in High Salt fed Wistar rats and is associated with a natriuresis and diuresis induced by this hormone
Authors: Cope Georgina , Houghton Belinda L , Healy Vincent , Johns Edward J
Published: June 2021

This study investigated whether high dietary Na+ intake, from weaning (4 weeks) to adulthood (11 weeks) influenced the RSNA, natriuretic and diuretic responses to intra‐renal infusion of γMSH. In anaesthetized (urethane/chloralose) male Wistar rats fed normal (N) Na+ (0.3%, n=3) or high (H) Na+ (3%, n=5), cannulae were inserted into the bladder for urine collection, into the cortico‐medullary boarder of the right kidney, the femoral artery to measure mean arterial pressure (MAP) and femoral vein. RSNA was recorded from nerves to the left kidney. Data, mean±SEM were compared using paired t‐tests and P<0.05 indicated significance. Infusion of γMSH into the right kidney (29.4 nM, 1ml/h), increased fractional Na+ excretion to a greater extent in the HNa+ (165±14% P<0.01) as compared to the NNa+ group (9±5%), raised urinary volume more in HNa+, 35±12.7 μl/min/kg (P<0.03) than NNa+, 8.1± 5.4 μl/min/kg and RSNA was elevated more in HNa+, 46±10% (P<0.001) than NNa+, 0.4±0.1%. MAP was similar on both diet regimens (NNa+, 96±3mmHg; HNa+ 96±1mmHg) and did not change during γMSH infusion (NNa+ 88±4mmHg; HNa+ 88±8mmHg). These data demonstrate that the augmented natriuretic and diuretic effect induced by right renal γMSH infusion in HNa+ rats occurs with an elevation in left RSNA. Funding: SFI RFP2007/BIMF514.
Cardiovascular and Renal Responses Produced by the Central Microinjection of Salvinorin A in Ketamine/Xylaxine‐Anesthetized Rats
Authors: Gottlieb Helmut B , Ji Lisa , Cunningham JT
Published: June 2021

One of active ingredients of Salvia divinorum, Salvinorin A (Sal A), has been shown to be a kappa opioid receptor agonist. The activation of central kappa opioid systems markedly affects renal function (water diuresis) in a manner that is different from any clinically used diuretic to date. The cardiovascular and renal effects produced by central administration of Salvinorin A are yet to be determined.

Methods

Sprague‐Dawley rats were implanted with chronic arterial, venous and bladder cannulas and infused with isotonic saline (55 ml/min, iv) containing ketamine (1 mg/Kg/min) and xylazine (80 mg/Kg/min). After equilibration, urine was collected during two control periods (C, 10‐min ea) and immediately after ICV Salvinorin A (10 nmol or 30 nmol) for 80 min (10‐min ea). Controls received injections of vehicle (DMSO) into the lateral ventricle (n=6).

Results

ICV injection of Salvinorin A markedly increased V without significantly changing UNaV or blood pressure.

Conclusion

In anesthetized rats, Salvinorin A selectively affected urine output (diuresis), whereas the activation of central kappa receptors U‐50488H affects both urine flow and UNaV. From these studies, it is apparent that Salvinorin A's effects on renal differ from those elicited by central kappa agonists (endogenous and synthetic). Supported by HL62579 and NIH EARDA grant.
Renal outer medullary oxidative stress is dependent upon elevated renal perfusion pressure in angiotensin II‐induced hypertensive rats
Authors: Polichnowski Aaron James , Jin Chunhua , Yang Chun , Cowley Allen W.
Published: June 2021

Renal outer medullary (OM) injury in angiotensin II (AngII)‐infused rats is largely pressure dependent. We investigated the role of elevated renal perfusion pressure (RPP) versus circulating AngII on renal OM oxidative stress and nitric oxide synthase (NOS) activity in male Sprague Dawley rats. An aortic balloon occluder positioned between the renal arteries maintained RPP to the servocontrolled (SC) left kidney at baseline levels while the uncontrolled (UC) right kidney was exposed to elevated RPP during 14 days of AngII (25 ng/kg/min) infusion. RPP in UC kidneys was higher (p < 0.05) compared to SC kidneys and sham rats (170.3 ± .1, 117.3 ± .7, 115.8 ± .4 mmHg; respectively). OM superoxide production, determined using an oxy‐ethidium fluorescence assay, was higher (p<0.05) in UC vs. SC and sham kidneys (8149 ± 474, 7024 ± 472, 6465 ± 279 RFU, respectively). OM SOD activity (U/mL/ug protein) was unchanged in SC kidneys (2.3 ± .2), but was reduced (p<0.05) in UC vs. sham kidneys, (2.0 ± .2 vs. 2.7 ± .3, respectively). OM NOS activity (nmol cit/hr/mg protein) was increased (p<0.05) in UC (6.5 ± .7) and SC (7.0 ± .7) versus sham kidneys (4.3 ± .6). Elevated RPP tended (p=0.09) to lower OM NOS activity in UC vs. SC kidneys. In conclusion, elevated RPP stimulated excess OM superoxide production and tended to lower NOS activity in AngII‐induced hypertension, which can explain the significant pressure‐induced OM injury in this model.
High blood pressure in aged Fischer 344 X Brown Norway F1 rats is associated with increased oxidative stress, NFkB activation and exaggerated renal AT1R response to Ang II
Authors: Chugh Gaurav , Lokhandwala Mustafa , Asghar Mohammad
Published: June 2021

Aging is characterized by a progressive decline in physiological functions. Although the underlying mechanisms are not well understood, increasing number of evidence points towards oxidative stress as one of the primary determinants of aging. In this study, we compared 3 month‐ (adult) and 21 month‐ (aged) old Fischer 344 X Brown Norway F1 rats for age‐related changes in kidney function. We measured blood pressure, sodium potassium ATPase activity in proximal tubules, AT1 receptor binding in proximal tubular membranes, NFkB transcription factor in nuclear fractions and oxidative stress markers such as protein carbonyls and urinary 8‐isoprostane. Our results showed an increase in systolic, diastolic and mean arterial blood pressure in aged animals. In response to Ang II, there was increased stimulation of sodium potassium ATPase in aged animals accompanied by increased AT1R binding. Protein carbonyls and 8‐isoprostane were also increased in aged animals. We also found increased NFkB in nuclear fractions from aged animals. While Ang II activates NFkB through AT1 receptors, NFkB has putative response elements on AT1 receptor promoter. Therefore, it appears that age‐related increase in oxidative stress increased renal AT1R function via activating NFkB. This may have caused increased sodium retention and hypertension in aged animals (NIH/NIA AG25056, AG29904).
Angiotensin (Ang) II mediated thrombosis in cremaster muscle microvessels.
Authors: Senchenkova Elena , Russell Janice M , Vital Shantel , Granger D. Neil
Published: June 2021

Hypertension is associated with an increased risk of thrombosis. The aims of this study were to determine whether AngII‐induced thrombosis occurs in arterioles and/or venules, and whether the thrombosis is mediated by AT1‐ or AT2‐receptors. Thrombosis in mouse cremaster microvessels was quantified after light/dye injury using the time of onset of the thrombus and time to blood flow cessation. Wild type (WT), AT1R deficient (AT1R−/−), and AT1R−/− to WT bone marrow chimeras (AT1R−/−Chim) were implanted with an AngII‐loaded Alzet pump (1 ug/kg/min) for 2 wks. AngII administration in both WT and AT1R−/− mice significantly accelerated thrombosis in both arterioles and venules. Losartan, while reducing the AngII‐induced hypertension, did not affect the accelerated thrombosis caused by AngII in WT mice but it significantly increased thrombosis in AT1R−/−Chim arterioles. Inhibition of AT2R in WT mice with PD123319 significantly blunted the AngII enhanced thrombosis response (onset), but only in arterioles. Our findings indicate that AngII‐induced hypertension is accompanied by enhanced thrombosis in both arterioles and venules. The AngII‐mediated thrombosis in arterioles does not involve AT1R dependent signaling. (HL26441).
GPR30 activation in salt‐sensitive mRen2.Lewis females induces beneficial effects independent of alterations in blood pressure
Authors: Lindsey Sarah Hoffmann , Chappell Mark C.
Published: June 2021

Female mRen2.Lewis (mRen2) rats display only mild increases in blood pressure in comparison to male littermates unless ovariectomized or fed a high salt (HS) diet. This estrogen‐ and salt‐sensitive model may reflect the higher pressure and salt‐sensitivity associated with the postmenopausal state. We reported that in vivo activation of the novel estrogen receptor GPR30 by the agonist G‐1 significantly reduced blood pressure and Ang II‐induced vasoconstriction in ovariectomized mRen2. The current study assessed whether GPR30 activation ameliorates salt‐sensitive hypertension and vascular dysfunction in intact mRen2 fed a HS diet (4% Na+, 10 wks). Systolic pressures in HS females treated with G‐1 were not different from HS controls (G‐1: 225±4 vs. 238±9 mmHg; n=5 each). G‐1 significantly reduced Ang II vasoconstriction in both endothelium‐intact (10% vs. 16%; P <0.01) and denuded aortic rings (19% vs. 26%; P <0.05). In addition, G‐1 reduced renal hypertrophy (4.4±0.1 vs. 5.0±0.1 mg/g body weight; P <0.01) and cardiac hypertrophy (4.8±0.1 vs. 5.4±0.1 mg/g; P <0.01). G‐1 also enhanced creatinine clearance (1.94±0.3 vs. 0.97±0.2 ml/min; P <0.05) and reduced proteinuria (98±33 vs. 331±67 mg/mg creatinine; P <0.05). We conclude that activation of the estrogen receptor GPR30 induces beneficial cardiovascular actions in the salt‐sensitive mRen2 strain independent from changes in blood pressure.
Modeling Forearm Vascular Mechanics in Hypertension
Authors: Norton Katelyn N , Zamir Mair , Frances Maria , Usselman Charlotte W , Fleischauer Arlene , Shoemaker J. Kevin
Published: June 2021

An emerging hypothesis states that vascular disease is initiated within the microvasculature. Using a modified Windkessel model, lumped mechanical properties of the forearm vascular bed were examined to determine the effect of chronic hypertension on the blood supply to skeletal muscle. Systemic pulse pressure (PP; Finometer), brachial artery radius (BAR; Ultrasound), vascular bed compliance (C), and resistance (R) were measured in (I), Hypertensive (HT) patients with controlled blood pressure (CBP) and high glucose (HG)(n=8), (II) HT patients with CBP and normal glucose (NG)(n=10), (III) HT patients with uncontrolled blood pressure (UBP) and HG (n=18), (IV) HT patients with UBP and NG (n=16), and (V) age‐matched, healthy controls (n=27). R was decreased and BAR was increased in UBP groups with HG levels compared to all other groups (p<0.05). PP was found to vary across groups, but was unrelated to C. These findings support a model of systolic HT which is consistent with the PP results. UBP with high glucose appears to initiate hypertrophic remodelling leading to reduced vascular R. However, from a vascular mechanics perspective, hypertension, with or without high glucose, does not modify microvascular compliance in skeletal muscle. Supported by Canadian Institutes of Health Research, NSERC, and the Canadian Diabetes Association.
ANTIHYPERTENSIVE EFFECT OF THE NOVEL FAAH INHIBITOR AM3506
Authors: Batkai Sandor , Godlewski Gregorz , Liu Jie , Nikas Spyros P , Makriyannis Alexandros , Cravatt Benjamin F , Pacher Pal , Kunos George
Published: June 2021

The endocannabinoid system (ES) has been implicated in the regulation of blood pressure. We have previously shown that inhibition of fatty acid amide hydrolase (FAAH), the enzyme that degrades endogenous anandamide, transiently normalizes the elevated blood pressure and cardiac contractility in different experimental models of hypertension. Here we tested the effects of a novel, selective, highly potent and in vivo effective FAAH inhibitor, AM3506, in SHR and WKY rats. AM3506 has a Ki of 31 nM for FAAH, with much lower affinity for other ES targets. At a dose of 0.1 mg/kg i.p., AM3506 caused >85% inhibition of brain FAAH with no appreciable inhibition of other serine hydrolase targets. In anesthetized SHR, basal mean arterial pressure (MAP, 179.8±7.6 mmHg) was reduced to 113.7±20.4 mmHg by 1mg/kg AM3506 with no sign of recovery for over an hour. Left ventricular (LV) function was analyzed using pressure‐volume catheter system. LVESP, dP/dt, SV, CO and TPR were elevated in SHR compared to WKY and were markedly reduced by 1 mg/kg AM3506. In awake, freely moving SHR, AM3506 caused a dose‐dependent and long lasting reduction in MAP (173.0±3.8 to 126.0±2.2 mmHg). The effects of AM3506 in both anesthetized and conscious SHR could be prevented by CB1 antagonist pretreatment, suggesting that they are triggered by the rise in endogenous anandamide acting via CB1 receptors. Because inhibition of FAAH does not elicit behavioral effects predictive of addictive potential, FAAH inhibitors such as AM3506 may be considered for the treatment of hypertension.
The pressor effect of water: mechanism and location of action
Authors: McHugh Julia , Raj Satish , Diedrich Andre , Appalsamy Martin , Robertson David
Published: June 2021

Water ingestion induces a robust, sustained pressor response in patients with baroreflex impairment and in mice with sinoaortic deafferentation (SAD). The mechanism of water's effect on blood pressure remains unknown. In order to isolate the location at which water acts, SAD mice were given water via intragastric or intraduodenal routes. In both cases a similar pressor response appeared. The presence of a pressor response following intraduodenal infusion indicates that the pharynx, esophagus, and stomach are not critical sites for water's pressor action. Administering an identical volume of physiological saline did not induce a significant pressor response. Osmolality of portal and systemic circulations was measured 15 minutes post intraduodenal water infusion and found to be 292.7 and 304.4 mOsm/kg, respectively. TRPV4 is an osmo‐sensitive cation channel found throughout the body, and has been reported to be activated under hypotonic conditions. To investigate the potential role of TRPV4 in water's pressor response, animals lacking TRPV4 were given water intraduodenally. Compared to wild type, TRPV4 ‐/‐ animals had a greatly diminished pressor response to water. We conclude that the pressor effect of water is not dependent on pharyngeal, esophageal, nor gastric mechanisms; portal osmolality is reduced following water administration; and that the TRPV4 channel is essential for water's effect.
Dietary Quality is not Determined by Children's Willingness to Try F&V.
Authors: Onufrak Steve , McCabe‐Sellers Beverly , Lovera Dalia , Bogle Margaret
Published: June 2021

Introduction

Fruit and vegetable (F&V) consumption is generally inadequate among children and lack of willingness to try F&V is often cited as a reason for this. We examined whether dietary quality and F&V consumption differed according to children's objectively measured willingness to try F&V.

Methods

Research was conducted at a summer day camp program in Marvell, AR attended by 84 AA children ages 5‐12. Dietary quality was measured using Healthy Eating Index‐2005 (HEI‐05) components based upon 24‐hour recalls. Children were offered a variety of F&V items as an afternoon snack over 6 weeks. Willingness to try an item was defined as consumption of 20% of item weight. Children who tried at 75% of F&V items offered were classified as "triers".

Results

The mean number of F&V offered was 16.7 (range 1 to 27). Overall HEI‐05 did not differ by trier status (Mean HEI 44.1 for triers, 45.6 for non‐triers, p=0.56). No differences were observed between F&V triers and non‐triers for HEI‐05 component scores for total fruit (1.6 vs. 2.2, p=0.18), whole fruit (1.2 vs. 0.9, p=0.51), total vegetables (2.2 vs. 2.0, p=0.60), or dark green and orange vegetables (0.3 vs. 0.7, p=0.16).

Conclusion

Unwillingness to try new F&V items was not associated with overall dietary quality or F&V consumption. Low consumption of F&V observed among children may be related to inadequate exposure and availability rather than lack of willingness to try them.
Cerebral non‐oxidative carbohydrate consumption in humans driven by adrenaline
Authors: Larsen Thomas Seifert , Brassard Patrice , Jorgensen Thomas Bech , Hamada Ahmad , Rasmussen Peter , Quistorff Bjørn , Secher Niels H. , Nielsen Henning B.
Published: June 2021

During brain activation, the decrease in the ratio between cerebral oxygen and carbohydrate uptake [6 O2/(glucose + 1/2lactate); OCI] is attenuated by the non‐selective beta‐adrenergic receptor antagonist propranolol, whereas OCI remains unaffected by the beta1‐adrenergic receptor antagonist metroprolol. These observations suggest involvement of a beta2‐adrenergic mechanism in non‐oxidative metabolism for the brain. Therefore, we evaluated the effect of adrenaline (0.08 micrograms kg‐1 min‐1 iv. for 15 min) and noradrenaline (0.5, 0.1 and 0.15 micrograms kg‐1 min‐1 iv. for 20 min) on the arterial to internal jugular venous concentration differences (a‐v diff) of O2, glucose, and lactate in healthy humans. Adrenaline (n=10) increased the arterial concentrations of O2, glucose and lactate (P < 0.05) and also increased the a‐v diff for glucose from 0.6 ± 0.1 to 0.8 ± 0.2 mM (mean ± SD; P < 0.05). The a‐v diff for lactate shifted from a net cerebral release to an uptake and OCI was lowered from 5.1 ± 1.5 to 3.6 ± 0.4 (P < 0.05) indicating a 8‐fold increase in the rate of non‐oxidative carbohydrate uptake during adrenaline infusion (P < 0.01). Conversely, noradrenaline (n=8) did not affect the OCI despite an increase in the a‐v diff for glucose (P < 0.05). These results support that non‐oxidative carbohydrate consumption for the brain is driven by a beta2‐adrenergic mechanism, making neurons abundantly provided with energy when plasma adrenaline increases.
Effects of central insulin treatment on the mechanisms controlling energy balance in male and female juvenile rats
Authors: Keen‐Rhinehart Erin M , Liljelund Patricia , Desai Mina , Ross Michael G
Published: June 2021

The incidence of juvenile obesity is increasing at an alarming rate. In adults, central insulin treatment decreases food intake, body weight and hypothalamic orexigenic neuropeptides in a sex dependent manner. Mechanisms regulating energy balance in juvenile animals are inherently different from those in adults due to differences in growth rates and hormonal milieu. Therefore, we sought to determine if central insulin treatment in juvenile rats (21 day old) would have similar effects on energy balance as those reported in adult rats. 24 h food intake was measured after male and female rats were injected with saline, 0.1 or 0.5 U insulin icv just before lights out, and all rats received all treatments in a counterbalanced fashion with 48 h between injections. Additional sets of animals were used to assess the effects of insulin on c‐fos protein expression and NPY mRNA. Insulin treatment increased meal latency, decreased food intake, increased neuronal activation and decreased hypothalamic NPY expression. Unlike previous adult studies, there were no sex differences and decreases in food intake were small (10‐30%) with central insulin treatment. Therefore, central mechanisms regulating juvenile energy balance are significantly different from those in adults, and further study of these mechanisms should generate information to combat the increasing incidence of juvenile obesity. Funded by: NIH 1R01HD054751‐01A2
Association between physical activity, insulin resistance, body fat, and leptin in patients after gastric bypass surgery, obese, and non‐obese controls
Authors: Ramirez‐Marrero Farah A , Somaraju Madhuri , Vaa Brianna E , Roberts Shelly K , Joyner Michael J , Miles John , Curry Timothy B
Published: June 2021

Physical activity (PA) is inversely related with body fat, insulin resistance (IR), and leptin. However, these associations are not clear in patients after gastric bypass surgery (GBS). We hypothesized an inverse relation between PA, BMI, IR, and leptin; and a positive relation between leptin, BMI, and IR in a group of 9 patients after GBS, 8 obese (Ob), and 7 non‐obese (N‐Ob) controls (age=39.0±5.7, 27.7±6.9, 28.0±10.2 yr, respectively). Subjects wore an accelerometer from 6‐7 days, and underwent measurements of height, weight, DEXA, blood glucose, insulin and leptin. IR was estimated using HOMA. Between group differences in PA, BMI, IR, and leptin were determined with ANOVA; and the relation between these variables was determined with simple linear regressions. Between group differences were observed for BMI (Ob=38.7±1.6, GBS=30.4±1.5, N‐Ob=23.8±1.7 kg/m2), IR (Ob=3.0±0.5, GBS=1.1±0.5, N‐Ob=0.7±0.5), and leptin (Ob=55.9, GBS=28.7±4.5, N‐Ob=5.1±5.6 ng/ml). PA was not different between groups. Inverse associations were observed between PA and BMI (r= ‐ 0.55), and leptin (r= ‐ 0.56); and positive associations were observed between leptin and BMI (r= 0.92), and IR (r= 0.63). PA appears to be associated with the control of obesity and IR possibly via reductions in leptin, a mechanism that requires further study.

Funded by NIH CTSA UL1‐RR24150, NIH CTSA KL2‐RR024151
Lung microvascular mitochondria regulate TNFα‐induced TNFR1 shedding
Authors: Rowlands David John , Lindert Jens , Bhattacharya Jahar
Published: June 2021

Ligation of endothelial (EC) TNFα receptor 1 (TNFR1) by circulating tumor necrosis factor alpha (TNFα) promotes lung inflammation. TNFR1 shedding by inflammatory cells limits inflammation. However, it is not known whether TNFR1 shedding occurs in lung microvessels. To determine shedding mechanisms, we viewed ECs of single microvessels in inflated, isolated, blood‐perfused rat lungs by live confocal microscopy. To quantify cytosolic (Ca2+cyt) and mitochondrial (Ca2+mit) calcium levels, we co‐infused dyes fluo 4 AM and rhod 2 AM respectively. To determine TNFR1 EC expression, we infused vehicle or TNFα then microinjected a fluorophore‐conjugated TNFR1mAb followed with a buffer wash. After infusion of vehicle alone, Ca2+cyt and Ca2+mit oscillation amplitudes and EC TNFR1 expression were stable. By contrast, after TNFα infusion (1 ng/ml, 10 min) oscillation amplitudes increased two fold (p<0.05, n=3) and TNFR1 fluorescence decreased by 68±7% (p<0.05, n=4), indicating TNFR1 shedding. Pre‐infusion of TNFα converting enzyme (TACE) inhibitor TAPI‐1, or mitochondrial SOD mimetic, MnTBAP blocked TNFα‐mediated TNFR1 decrease. These findings imply novel signaling in which TNFR1 ligation enhances Ca2+mit oscillations, leading to increased mitROS triggering TNFR1 shedding. We provide the first evidence that TNFα induces TNFR1 shedding in lung EC in situ. We propose TNFR1 shedding limits lung inflammation.
Mitochondrial Clustering and Nuclear Reactive Oxygen Species Enrichment with Hypoxia and Flow
Authors: Reed Darla J , Swiger Brad , Patel Mita , Gillespie Mark , Al‐Mehdi Abu‐Bakr
Published: June 2021

Changes in oxygen tension and shear stress in vascular endothelial cells (ECs) activate specific signaling pathways utilizing second messengers produced by mitochondria. Since mitochondria are motile signaling organelles, mitochondrial redistribution may be an essential response to the changing requirements under hypoxia and flow. We hypothesize that hypoxia and shear stress results in cytoplasmic mitochondrial redistribution in ECs. To study this, rat pulmonary artery and microvascular ECs were subjected to either 3 h hypoxia or 6 h flow at 14 dynes/cm2, respectively. MitoTracker Red (MTR) was utilized to image and track mitochondrial movement. MTR signal was quantified in individual cells at different time points. Our results show increased perinuclear MTR signal at 3 and 6 h of flow and with 3 h hypoxia. Nocodozole abolished the mitochondrial translocation response in both hypoxia and flow. The probe DCF and a reactive‐oxygen species (ROS) sensitive GFP construct with a nuclear localizing sequence were used to study nuclear ROS. DCF studies revealed sustained nuclear ROS production with flow, and increased nuclear ROS production with hypoxia. Preliminary roGFP flow studies indicate nuclear oxidant stress at 1 h and 6 h. We conclude that hypoxia and flow induce microtubule dependent mitochondrial translocation, which may serve to create a nuclear ROS‐signaling mechanism.
Analysis of arginase and nitric oxide synthase (NOS) to excess collagen deposition in inhalation injury
Authors: Sousse Linda Elias , Wells Sandra , Enkhbaatar Perenlei , Esechie Aimalohi , Traber Daniel L
Published: June 2021

Approximately 15,000 United States victims of burn trauma have inhalation injuries and suffer from acute lung injury. Burn victims have decreased levels of arginine, which can contribute to excessive collagen synthesis. We hypothesize that lung arginase activity is increased by burn and inhalation injury in murine and ovine models, which contributes to collagen deposition. C57BL6 mice were divided into three groups (n=6): Control/Uninjured, pre‐injured, and injured mice with a burn and smoke injury. Female sheep were divided into the following groups (n=4): SHAM, Uninstrumented, and injured sheep with burn and smoke injury sacrificed after 4, 8, 12, 18, 24, and 96 hours and 2 weeks. Murine arginase activity (Control: 0.159 ± 0.004, Injured: 0.329 ± 0.076), MPO activity, NOx activity, and iNOS activity (p < 0.0001) significantly increased after the injury, and immunostaining showed septal thickening and edema. Arginase activity increased directly in sheep after increasing time after the injury. The increase in arginase activity could lower body arginine levels and lead to the uncoupling of NOS and the increase in asymmetrical dimethyl arginine formation. The increase in arginase is may be vital to the increase in collagen deposition and may interfere with gas exchange in the lung. Supported by the Shrine Hospital for Children Grant No. 8541
Tannic Acid Specific Inhibition of Angiotensin Type 1 Receptor in Rat Liver Epithelial Cells
Authors: Yesudas Rekha , Biju Prabath , Thekkumkara Thomas
Published: June 2021

Previous studies have shown that plant‐derived polyphenols appear to provide protection from hypertension. However, the target or mechanism of protective effects of polyphenols remains unclear. In the present study, we investigated the effects of tannic acid on angiotensin type 1 receptor (AT1R) expression. Exposure of rat liver epithelial cells to tannic acid resulted in significant down‐regulation of [3H]angiotensin II specific binding (81432±1981 to 40399±1952 dpm/mg protein) and AT1R protein (55%) and mRNA (60%) expression in a concentration and time dependent manner. The inhibitory effect of tannic acid on AT1R was specific and reversible. Under similar conditions, we observed increased phosphorylation of both MAP‐kinases (MAPK) p42 & p44. Pretreatment of cells with MAPK specific inhibitor prevented tannic acid induced MAPK phosphorylation and down regulation of the AT1R suggesting that the observed inhibitory effect is mediated through MAPK signaling intermediate(s). Our studies demonstrate for the first time that tannic acid inhibits the AT1R gene expression and illustrate that dietary polyphenols blunt hypertension, in part through inhibition of AT1R. Supported by NIH Grant DK072140
The differentiation potential of rat bone marrow stem cells to cartilage and integrin antibody can blocking this course in vitro
Authors: Deng Juan , Jin Huan , Liu Jian , Liu Yongming
Published: June 2021

Integrins mediate cell attachment to a variety of extracellular matrix proteins. These interactions play an important role in morphogenesis and differentiation. The mediating functions of integrins during chondrogenesis in vitro were investigated by using BMSCs of adult rat. This research have three groups:A,The cells were treated with anti‐β1‐ Integrin, dexamethasone, insulin, VitC .B,The cells were treated with TGF‐β3, dexamethasone, insulin, VitC .C,the control group .Cells were harvested after 7 and 14 days. The differentiation of the cells was investigated with bright‐field microscopy, the expression patterns of distinct proteins using immunohistochemistry and western blotting . the group A :The chondrocytes showed a strong proliferation. collagen I and II were downregulated; collagen II and Integrin‐β 1 was activated. But the blocking group could not happen,Integrin‐β1 were downregulated and the expression of collagen II was negative. These findings suggest that β1‐integrins play a crucial role in cartilage differentiation and point to a possible important cell‐matrix interaction in the induction of chondrogenesis .
Interleukin‐1β (IL‐1β) induced formation of embryoid body (EB)‐like structures in human term placenta derived stem cells
Authors: Strakova Zuzana , Reed Jennifer
Published: June 2021

Interleukin‐1 β (IL‐1 β) induced formation of embryoid body (EB)‐like structures in human term placenta derived stem cells

Human decidua parietalis placenta stem cells (hdpPSC) display pluripotency markers and are able to differentiate into mesenchymal lineages (osteoblasts, adipocytes, chondrocytes) as well as decidual cells (Strakova Z. et al., Cell Tissue Res 332:479, 2008). Moreover, hdpPSC express a basic marker for the endoderm, α‐fetoprotein, as well as nestin, a marker for neural/progenitor cells, suggesting the potential to differentiate into all three germ layers. Exposure (12‐40 days) to a stimulus mimicking an embryonic signal for decidualization (the cytokine IL‐1β with estradiol‐17β and medroxyprogesterone acetate) induced the formation of net‐like structures with dense cell aggregates. Round discrete conglomerates appear similar to EB structures described during the differentiation of embryonic stem cells. Continued growth resulted in a cystic appearance (200‐827 βm). Immunodetection of EB‐like structures showed retention of pluripotency markers SSEA‐4 and Oct‐4. Intensive cofilin staining confirmed the active reorganization of actin. The fixed specimen displayed simple mesodermal tissue morphology. It was positive for vimentin and α‐SMA and negative for α‐fetoprotein and cytokeratin. However, strong positivity for nestin in EB‐like structures confirms the early progenitor status of the cells and suggests the potential of these easily available cells as an alternative source of human stem cells.
HYPOXIC VASORELAXATION IN PORCINE CORONARY ARTERY IS NOT MEDIATED BY REACTIVE OXYGEN SPECIES
Authors: Paul Richard J. , Bowman Peggy Sue , Parr Anthony J. , Ishida Yukisato , Wardle Robert L. , Gu Min
Published: June 2021

Acute hypoxia dilates systemic arteries leading to increased tissue perfusion. Reactive Oxygen Species (ROS) have been proposed in oxygen‐sensing mechanisms modulating vascular smooth muscle contractility. ROS are also reported to relax human and porcine coronary arterioles. We tested the hypothesis that hypoxia induces coronary vasorelaxation via altering ROS. We used xanthine (X, 300 μM) with xanthine oxidase (XO, 30 mU/ml) as a ROS generator and N‐acetyl‐L‐cysteine (NAC, 10 mM) to scavenge ROS. X/XO relaxed endothelium‐denuded coronary artery contracted with U46619 or KCl. NAC blocked this X/XO relaxation but had little effects on the relaxation induced by hypoxia (aerating with N2). X/XO relaxation was associated with a decrease in [Ca2+]i, whereas N2 at high levels of stimulation could relax coronary artery without a decrease in [Ca2+]i. X/XO did not relax the α‐toxin permeabilized artery contracted with either buffered Ca2+ or GTPγS. In contrast, N2 relaxed permeabilized preparations despite fixed [Ca2+]. NAC blocked X/XO but not the N2 relaxation. Thus hypoxic vasorelaxation differs from the mechanism of ROS relaxation, which requires an intact sarcolemma and decreases [Ca2+]i. We conclude that hypoxic vasorelaxation of porcine coronary artery is not mediated by changes in ROS.
Influence of a Negative Hydrostatic Column and Central Fluid Shift via ‐6° Head‐down Tilt Posture on Cardiovascular Performance
Authors: Ade Carl J , Harms Craig A , Musch Tim I , Barstow Tomas J
Published: June 2021

Aims

To examine the influence of a negative hydrostatic column via ‐6° head‐down tilt (HDT) exercise on cardiovascular performance and to determine if the HDT posture stimulates greater cardiovascular adaptations during exercise training compared to upright (UPR).

Methods

9 males (21±2 yrs) performed VO2peak cycle exercise tests in the UPR, supine (SUP), and HDT positions. 9 different males (20±2 yrs) were endurance trained on a cycle ergometer in the UPR position for 8 wks (UPRTN) or in the UPR position for 4 wks followed by 4 wks in the HDT position (HDTTN).

Results

During acute exercise, VO2peak was decreased in the SUP and HDT positions compared to the UPR (2.01±0.46, 2.01±0.51 vs. 2.32±0.61 L/min respectively, P < 0.05). Stroke volume (SV) at 100 watts was greater in the HDT position compared to the UPR (77±5 vs 71±4 ml/beat, P < 0.05). Following training SV at 100 watts increased from 77±1 to 85±9 ml/beat in the HDTTN group during UPR exercise (P < 0.05). In addition, SV increased from 76±10 to 85±16 ml/beat in the HDT position for the same individuals (P < 0.05). SV in the UPRTN during 100 watts in the HDT position was unchanged but increased during UPR exercise following 8wks of training (65±3 to 75±5 ml/beat, P = 0.21).

Conclusions

HDT exercise increases sub‐maximal SV compared to UPR exercise. Training in the HDT position induces cardiovascular adaptations in both UPR and HDT exercise that are not achieved with UPR training.
Prediction of Changes in Orthostatic Tolerance after Head down Bed Rest With and Without Artificial gravity Training
Authors: Evans Joyce McClendon , Meng Martha , Patwardhan Abjihit , Stenger Michael , Feiveson Alan , Knapp Charles
Published: June 2021

In a recent study to evaluate the potential for artificial gravity (AG) to counteract spaceflight‐induced cardiovascular deconditioning, 8 men received a daily, one hour dose of AG (2.5 Gz ) while 7 underwent no countermeasure, during 21 days of head down bed rest (HDBR).

Results

After bed rest, AG‐treated subjects demonstrated greater orthostatic tolerance (OT) than control subjects, p = 0.012 (Stenger, 2008). Variables recorded during HDBR days were then analyzed to develop a model to predict OT before return to gravity. The variables evaluated represent control aspects of heart rate, blood pressure, spontaneous baroreflex activity, and breathing activity. From 16 available variables, 120 combinations were used to build a two variable model. The combination of high frequency spectral power of systolic blood pressure and mean blood pressure correctly classified subjects as trained or untrained 93% of the time. Predictive potential of this classifier was verified by bootstrap analysis.

Conclusions

Our data support the hypothesis that AG treatment lessens cardiovascular deconditioning in bed rested men. In addition, differences in AG treated and control subjects can be discriminated by a combination of variables related to regulation of blood pressure. This same combination of variables may be able to predict OT upon return from space. Supported by NASA AG‐Bed Rest Project (IMAG Pilot Study).
Cardiovascular Regulation During Artificial Gravity Stress
Authors: Evans Joyce McClendon , Ayanampudi Vijaya , Howarth Mark , Moore Fritz , Patwardhan Abjihit , Knapp Charles
Published: June 2021

Physiological deconditioning of astronauts returning from space may be lessened by inflight centrifuge usage. We assessed radius of rotation, G level and exercise components of an artificial gravity (AG) countermeasure for future use in preventing weightlessness‐induced cardiovascular deconditioning. 12 healthy, ambulatory men (35 ± 9 y, 83 ± 8 kg) underwent 4 AG and 1 earth gravity protocols that varied g level, radius of rotation and level of preexercise.

Radius and G level effects

Mean heart rate (HR) and sympathetic control of HR (Spectral power LF/HF of RR Interval) increased with increasing G level and radius.

Exercise effects

MHR increased with exercise and exercise prevented increased LF/HF and decreased HF/ (LF+HF) that occurred during the same protocol with no exercise.

Protocol duration effects

The sympathetic index increased, and parasympathetic index decreased, across the protocols.

CONCLUSIONS

Radius of rotation had the greatest effect on autonomic balance, while exercise had its greatest effect on mean HR. Autonomic balance shifted toward sympathetic dominance during centrifugation and this effect was lessened by exercise. Results support the idea that short radius AG plus exercise may provide an effective countermeasure to space flight deconditioning that may be more effective in preserving orthostatic tolerance than current countermeasures. Supported by KY NASA EPSCoR WKU62611, NASA Ames.
Bioavailability of gallic acid and catechins from neuroprotective grape seed extract is improved by repeated dosing in rats
Authors: Lobo Jessica Kathleen , Ferruzzi Mario G , Janle Elsa M , Whittaker Naomi , Cooper Bruce R , Weaver Connie M , Simon James E , Wu Qing‐Li , Welch Cara , Ho Lap , Pasinetti Giulio M
Published: June 2021

Grape Seed Extract (GSE), a rich source of biologically active phenolic acids and proanthocyanidins (PAC's), has demonstrated neuroprotective activities consistent with prevention of Alzheimer disease (AD). To understand how specific GSE components are absorbed, the impact of acute and repeated GSE exposure on bioavailability and brain deposition of major phenolics was investigated. Rats were pre‐treated with GSE acutely and in dose‐escalation from 50 to 150 mg/kg BW over 10 d prior to assessment of pharmacokinetic response. LC‐MS identified gallic acid (GA), catechin (C), epicatechin (EC) in plasma of rats gavaged with GSE. Additionally, 4‐methylgallic acid (4‐OMeGA), 3′‐methytlcatechin (3′‐OMeC) and 3′‐methylepicatechin (3′‐OMeEC) were identified as circulating metabolites of GSE phenolics. Repeated daily exposure to GSE was found to significantly increase bioavailability relative to animals receiving a single acute GSE dose. EC and C were not detectable in brain tissues of rats receiving a single GSE dose but reached levels of 290.7±45.9 and 576.7±227.7 pg/g respectively in brain of rats administered GSE for 10 d. These results suggest that GA, C and EC are readily absorbed and metabolized from acute doses of GSE and that plasma response and brain deposition of these neuroprotective phenolic compounds may be enhanced by repeated dosing. Supported by NIH‐NCCAM grant P01AT004511‐01.
Effect of black garlic on acute alcohol‐induced hangover and chronic alcohol‐induced liver injury in rats
Authors: Kim Min Hee , Kim Mi Yeon , Son Chan Wok , Cheong Sun Hee , Kim Mee Ree
Published: June 2021

The hepatoprotective effect of black garlic against ethanol‐induced oxidative damage was investigated in adult male SD rats. Black garlic (50, 100 and 400mg/kg) and ethanol (15mL/kg, 20% w/v) were administered orally to animals for 4 weeks. To investigate anti‐hangover effect, alcohol and acetaldehyde concentration of blood were measured at 1, 3, 5 and 7 h after oral black garlic and ethanol treatment. Blood alcohol and acetaldehyde concentration were dose‐dependently reduced in BG compared to ET. Serum alanine transaminase, aspartate transaminase, alkaline phosphatase, lactate dehydrogenase activities of BG were significantly decreased compared to those of ET. Lipid peroxidations of BG were significantly decreased in blood, liver, heart and kidney, compared to those of ET. Glutathione content in liver and RBC, antioxidant and anticancer enzyme activities such as glutathione peroxidase, glutathione reductase, catalase, quinone reductase and glutathione‐S‐transferase were improved in rats administered black garlic. The pretreatment of black garlic also significantly decreased by 45% in cytochrome P450 2E1 (CYP2E1) activity as well as lymphocyte DND damage expressed by tail length using the comet assay. These results support that the pretreatment of black garlic could provide preventive effect against alcohol‐induced liver injury through suppression of lipid peroxidation and oxidative DNA damage.
Tandem mass spectrometry method to measure serum 25‐hydroxy‐vitamin D concentrations for the National Health and Nutrition Examination Survey (NHANES)
Authors: Schleicher Rosemary Lawless , McCoy Leslie F , Chaudhary‐Webb Madhu , LaVoie Donna J , Chen Huiping , Pfeiffer Christine M , Phinney Karen W
Published: June 2021

CDC has measured 25‐hydroxy‐vitamin D for NHANES using the DiaSorin RIA since NHANES III (1988‐94). Starting with NHANES 2007‐08, a tandem mass spectrometry method (LCMSMS) using a stable isotope internal standard will be used to measure 25‐hydroxy‐vitamin D2 (VID2) and 25‐hydroxy‐vitamin D3 (VID3). The method (Clin Chim Acta 2008;391:6) was recently revised to provide better chromatographic resolution, better sensitivity, and automation of sample preparation. Robotic volume delivery, robotic mixing and 96‐well plate format permit high throughput sample processing. The chromatographic run time is <10 min. Limits of detection are ≤1 ng/mL. Analytical coefficients of variation are <10% for VID3. Results for standard reference material (SRM 972) from the National Institute of Standards and Technology indicated acceptable accuracy for VID2 and VID3. Because of periodic fluctuations in long‐term quality control pools using RIA, samples from NHANES 2001‐06 are being tested using the LCMSMS method and conversion equations for LCMSMS‐RIA are being developed for each year. Samples (100/yr) were selected based on 2 criteria: 1) proportionally distributed RIA results (25 samples per unweighted quartile) and 2) an even distribution of RIA assay performance spread throughout the year. The goal of this change of methods is to improve VID assay precision. The simultaneous availability of SRM 972 will insure accuracy.
Defining the role of Notch3 in smooth muscle differentiation and blood vessel formation
Authors: Liu Hua , Lilly Brenda
Published: June 2021

The heterotypic communication of endothelial cells and mural cells (pericytes, smooth muscle cells or fibroblasts) is crucial for the assembly and subsequent function of blood vessels. We have demonstrated that Notch3 is strongly induced in mural cells upon coculture with endothelial cells in vitro. To assess the significance of Notch3 on blood vessel formation, we silenced Notch3 by siRNA in mural cells and cocultured them with endothelial cells in a 3‐dimensional angiogenesis assay. Interestingly, deletion of Notch3 decreased endothelial‐promoted smooth muscle differentiation and attenuated mural cell‐enhanced angiogenesis. In vivo, Notch3 is selectively expressed in mural cells, including retinal pericytes, and our data show that Notch3 deficient mice exhibit decreased expression of smooth muscle α‐actin and enlarged arteries in retinas. Furthermore, preliminary results indicate that Notch3 expression is perturbed in a mouse model of retinopathy of prematurity (ROP). Our study provides evidence that during blood vessel formation the expression of Notch3 in mural cells is modulated by endothelial cells, which in turn serves to facilitate the differentiation of mural cells and regulate blood vessel formation. Supported by NIH HL076428.
GADD45 INDUCTION IN THE LIVER OF RATS FED ETHANOL CHRONICALLY
Authors: Oliva Joan , French Samuel W , Bardag‐Gorce Fawzia
Published: June 2021

Ethanol metabolism generates a high level of oxidative stress in the cell by increasing the levels of reactive oxygen species, which is responsible for hepatotoxicity and impairs the replication of normal hepatocytes. Recovery of the liver from ethanol injury requires replacement of dead cells. It is hypothesized in this study that a chronic exposure to an elevated level of oxidative stress, generated by chronic ethanol feeding, may cause cell cycle to switch to a proliferating state. GADD45 proteins are key players in cellular stress responses, and their activation results in cell cycle arrest, DNA repair, cell survival and senescence, or apoptosis. GADD45 proteins function is then dictated by the extent and nature of the stress stimuli, which results in their association with cell death or cell survival partners. Chronic ethanol feeding and proteasome inhibition caused a significant up regulation of GADD45 gene expression and protein levels, which was associated with a marked oxidative stress, a decrease in cell death pathways (p38, Erk, and JNK), and an increase in proliferating cell nuclear antigen (PCNA), in the livers of rats fed ethanol. PI3K pro survival pathway (phospho‐Akt threonine 308) was also increased, which suggests that cell survival is manifest. GADD45 proteins are partner of the PI3K/Akt pathway, promoting cell survival by protecting hepatocytes from genotoxic stress induced by chronic ethanol feeding and by ethanol induced proteasome inhibition. These results provide new insights towards defining the molecular mechanisms of ethanol effects on the cell cycle. Supported by NIH/NIAAA Grants 8116 and P50‐011999 Alcohol Center Grant, Liver/Pancreas.
Hypoxia‐inducible factor‐dependent production of profibrotic mediators by hypoxic Kupffer cells
Authors: Copple Bryan Lloyd , Moon Jeon‐OK
Published: June 2021

Liver fibrosis develops when chronic liver injury stimulates cells in the liver to produce mediators that activate hepatic stellate cells and stimulate them to secrete collagen. Recent studies have shown that the hypoxia‐regulated transcription factor, hypoxia‐inducible factor‐1α (HIF‐1α), is essential for upregulation of profibrotic mediators, such as platelet‐derived growth factor (PDGF), in the liver during the development of liver fibrosis. What remains unknown, however, is the cell type‐specific regulation of profibrotic mediators by HIFs. Accordingly, in the present study the hypothesis was tested that HIFs regulate production of profibrotic mediators by hypoxic Kupffer cells. Exposure of Kupffer cells isolated from Control mice to 1% oxygen activated HIF‐1α, and increased mRNA levels of PDGF‐B, vascular endothelial cell growth factor, Angiopoietin‐1, and monocyte chemotactic protein‐1. Upregulation of all of these mediators by hypoxia was prevented in Kupffer cells isolated from hypoxia‐inducible factor‐1β‐Deficient mice. Results from these studies suggest that HIFs are critical regulators of profibrotic mediator production by hypoxic Kupffer cells. This study was supported by NIH grants DK073566 and RR021940.