bluuebunny/crossref_metadata_2025_split huggingface dataset:
Role of blood pressure in chronic aldosterone‐mediated cardiac injury (701.5)
Authors: Ball Jana , Syed Maryam , Maranon Rodrigo , Reckelhoff Jane , Yanes Cardozo Licy , Iyer Rugmani , Lindsey Merry , Romero Damian 
Published: June 2021

Excess aldosterone (ALDO) causes hypertension (HTN), and cardiac hypertrophy, injury and dysfunction. The role of HTN in ALDO‐mediated cardiac injury remains controversial. We aim to study the role of blood pressure (BP) in chronic ALDO‐mediated cardiac hypertrophy and fibrosis.Eight‐week old uninephrectomized male Sprague Dawley rats (N=6/grp) were implanted with radiotelemetry probes for BP monitoring and allowed to recover for 2 wks. Animals were assigned to 4 groups: Control, ALDO (0.75 µg/h)/SALT (1.0 % NaCl + 0.3 % KCl in drinking water), ALDO/SALT+2‐AHT (240 mg/kg hydralazine and 15 mg/kg reserpine in the food) or ALDO/SALT+3‐AHT (2‐AHT plus 75 mg/kg hydrochlorothiazide). Tissue weights and cardiac fibrosis were determined at the end of the 8‐week experimental period.All three ALDO‐treated groups reached the same BP value at the end of the 8‐wk period. However, the MAP area under the curve (AUC) was decreased in 2‐AHT (1.47 AU vs. ALDO, p<0.05; vs. 3‐AHT, p<0.05) and 3‐AHT (1.29 AU vs. ALDO, p<0.0.5) vs. ALDO (1.73 AU vs. control, p<0.05). Cardiac fibrosis positively correlated with MAP AUC (R2=0.51, p<0.05) as well as with heart, left ventricle, kidney and lung weights.These results suggest that ALDO‐mediated cardiac hypertrophy and fibrosis is BP‐dependent without excluding that ALDO may exacerbate the HTN‐mediated cardiac injury. Stricter BP management may benefit patients with elevated ALDO levels.Grant Funding Source: Supported by American Heart Association Grant 12SDG8980032.
REDD1 reduces the responsiveness of mTORC1 after resistance exercise and amino acid intake in skeletal muscle of elderly people (702.4)
Authors: Francaux Marc , Demeulder Bénédicte , Naslain Damien , Fortin Raphaël , Lutz Olivier , Caty Gilles 
Published: June 2021

The aim of the present experiment was to highlight the difference in mTORC1 regulation between young and elderly people after exercise and amino acid intake. Eight younger (23±1 y) and 8 older (70±7 y) healthy volunteers were recruited. After an overnight fast, a first biopsy sample was taken in the vastus lateralis muscle. Then, the subjects performed a one‐leg resistance exercise consisting in 10 sets of 10 leg extensions at 70% of their 3‐RM (repetition‐maximum) previously measured. Immediately after the exercise completion, the subjects drank a beverage containing 30 g of whey protein hydrolyzate whose 2.5 g was leucine. Thirty minutes after the beverage intake, a second biopsy was taken in the exercised leg and a third one in the contralateral leg. In both groups, feeding increased the S6K1 phosphorylation and resistance exercise potentiated this effect. However, the range of these increases was about the half in elderly as compared to the young subjects confirming a reduced responsiveness of mTORC1 in elderly people. Feeding doubled the phosphorylation of PKB (Ser473) in both groups. Resistance exercise reinforced this effect in young but not in elderly people. The expression of REDD1 was systematically higher in elderly people. REDD1 was slightly and not significantly increased by exercise in young subjects whereas it was doubled in elderly suggesting that REDD1 is probably a major actor for the development of anabolic resistance during ageing. The phosphorylation state of PRAS40 (Thr246) increased after feeding but similarly in both groups. The phosphorylation state of AMPK (Thr172) was affected neither by feeding nor by exercise. All together, these results indicate that mTORC1 acts as a molecular integrator receiving positive and negative signals from its upstream regulators. The reduced responsiveness to anabolic stimuli observed in elderly people seems related to a higher REDD1 expression combined with a lower exercise‐induced activation of PKB.Grant Funding Source: Supported by the Walloon Region (Plan Marshall – Wagralim ‐ Geramino)
Effect of early and late outpatient exercise training on muscle mass and protein kinetics in severely burned children (702.5)
Authors: Hardee Justin , Porter Craig , Sidossis Labros , Carson James , Herndon David , Suman Oscar 
Published: June 2021

Severe thermal trauma is associated with profound muscle wasting and long‐term functional impairments in burn survivors. Late exercise training performed 6 to 9 months post‐injury increases leg lean mass (LM) in burned children. The impact of early outpatient exercise, initiated immediately following hospital discharge, on muscle mass has yet to be examined. Therefore, we examined the effects of early and late outpatient rehabilitative exercise training (RET) on muscle mass and protein kinetics in severely burned children. Eighty‐six children with 蠅40% total body surface area burn were randomized to 12‐weeks standard of care rehabilitation (SoC) or RET at discharge (DC) and 6 months (6M) post‐burn. DEXA was used to determine changes in LM. In a subset of patients (N=30), stable isotope infusion studies were conducted to determine muscle protein synthesis (MPS). RET increased LM compared to SoC at each time‐point (DC: 4.7% vs 17.0%; 6M: 3.0% vs 13.0%). No differences in LM were found between RET interventions. MPS decreased from DC to 6M (6.3 ± 1.4% and 3.4 ± 0.6%, respectively); however no differences were observed between SoC and RET. No changes in MPS were observed from 6 to 9 months. In addition, no differences in blood flow were found with each treatment. These results demonstrate that improvements in LM can be achieved immediately following hospital discharge and 6 months post‐burn without alterations to basal muscle protein turnover. Early and late outpatient RET are effective methods to augment muscle mass following severe burn injury.Grant Funding Source: Supported by NIDRR grant H133A120091; NIH P50 GM060388, R01 HD049471, R01 GM056687
Daily living physical activities and muscle protein synthesis: a new and applied method with intrinsically stable isotope‐labeled milk proteins as tracer (702.8)
Authors: Reitelseder Søren , Bülow Jacob , Agergaard Jakob , Kjaer Michael , Holm Lars 
Published: June 2021

Aims of this study were to evaluate effects of daily physical activities on muscle protein synthesis (MPS) and to validate a tracer protocol with intrinsically labeled milk proteins. 24 elderly (70 ± 1 y) men were recruited and randomly assigned to: inactivity (IA), daily activities (DA), or strength exercise (SE). The study protocol simulated a normal daily eating routine containing carbohydrates, fat, and [1‐13C]leucine‐labeled whey and caseinate as the primary protein source. Regular ingestion of labeled protein served to prime (whey) and maintain (caseinate) tracer enrichment for determination muscle protein fractional synthesis rates (FSR). Physical activities were monitored and venous blood and muscle biopsies collected. Total physical activity was highest in DA compared to IA and SE. Protein ingestion increased leucine and phenylalanine plasma concentrations in all groups. Plasma [1‐13C]leucine enrichment was stable throughout the 10‐h FSR measurement period. Muscle protein FSR were for IA, DA, and SE 0.065 ± 0.0050 %/h, 0.077 ± 0.0081 %/h, and 0.081 ± 0.0057 %/h, respectively (means ± SE, one‐way ANOVA P = 0.199). The prerequisites for calculating FSR was fulfilled with the tracer coming solely from oral intake of milk proteins. Under these applied settings it was not possible to detect significant differences in MPS between the inactivity, daily activities, and strength exercise interventions.Grant Funding Source: Supported by Arla Foods Ingredients P/S and Lundbeck Foundation
Salivary mtDNA copy number: index of aerobic efficiency? (705.6)
Authors: Chen Yang , Hill Helene , Klein Jacquelyn , Ndirangu Duncan , Falvo Michael 
Published: June 2021

Objective: Mitochondrial DNA (mtDNA) is central to oxidative phosphorylation and energy production. mtDNA copy number (mtDNAcn) may serve as an index of mitochondrial density, but has not been well studied in saliva. Our goal was to determine whether salivary mtDNAcn is related to measures of aerobic efficiency and fitness.Methods: 15 men (32±8.3 yrs) volunteered for this study and performed exercise challenge testing, completed physical activity questionnaires, and provided a saliva sample for mtDNAcn analysis. Relative mtDNAcn was determined by real‐time PCR in saliva DNA from individuals. Subjects were assigned to HIGH and LOW aerobic efficiency groups based on the ratio of ventilation and oxygen consumption (Ve/VO2). Variables of interest were mtDNAcn, maximum oxygen consumption (VO2/kg), respiratory exchange ratio (RER) and physical activity scores.Results: Ve/VO2 was significantly correlated with relative mtDNAcn (R2=0.32, p=0.03). HIGH aerobic efficiency group had significantly higher mtDNAcn (t=2.34, p=0.03), VO2/kg (t=3.25, p<0.01), physical activity scores (t=2.24, p=0.04) and a lower RER (t=2.50, p=0.03) than LOW aerobic efficiency group.Conclusions: mtDNAcn is related to aerobic efficiency such that individuals with HIGH aerobic efficiency have significantly greater mtDNAcn. Future studies may consider salivary mtDNAcn in the evaluation of exercise tolerance and efficiency.Grant Funding Source: VA Grants 1I21RX001079‐01 and 1I21CX000797‐01
Exercise causes repositioning of the ‐1 nucleosome within the PGC1α promoter in association with altered gene expression in skeletal muscle (705.7)
Authors: Henagan Tara , Covington Jeffrey , Stewart Laura , Galgani Jose , Ravussin Eric , Bajpeyi Sudip 
Published: June 2021

Skeletal muscle PGC1α expression is epigenetically regulated by promoter methylation. Methylation status at the ‐260 nucleotide (nt) within the promoter plays an important regulatory role in determining PGC1α expression and consequently mitochondrial number and function and insulin sensitivity. Here we identified ‐1 nucleosome (‐1N) position within the PGC1α promoter in muscle from sedentary, lean men (n=18, aged 24±1 yrs, BMI 23.8±0.4) before and immediately after an acute bout of exercise (50% VO2max, ~650 kcal). Nucleosome position was measured by scanning PCR. At baseline, the ‐1N position spanned the promoter region from nt ‐350 to ‐190, covering the regulatory ‐260 nt methylation site. Following the exercise bout, the ‐1N was repositioned upstream, spanning the region from nt ‐500 to ‐300. PGC1α expression was significantly increased (1.05±.08 to 1.29±0.11 fold change, P = 0.02) following the exercise bout. Increased PGC1α expression was correlated with the upstream ‐1N position following the exercise bout (R2 = 0.43, P = 0.03). We provide evidence that an acute bout of exercise repositions the ‐1N in the PGC1α promoter upstream of the regulatory ‐260 nt methylation site, which may prevent DNA methyltransferase recruitment and methylation thus causing increased gene expression.Grant Funding Source: Support by NIH NIDDK 5T32‐DK064584‐09 (TMH)
The role of skeletal myofiber VEGF in the cerebral neurogenic response to exercise (706.21)
Authors: Rich Benjamin , Scadeng Miriam , Wagner Peter , Breen Ellen 
Published: June 2021

Exercise induces cerebral neurogenesis. This phenomenon has been suggested to require peripheral vascular endothelial growth factor (VEGF). We hypothesized that skeletal myofiber VEGF may regulate blood flow and neurogenesis in the hippocampus. This was tested in adult skeletal myofiber specific VEGF gene ablated mice (skmVEGF‐/‐) provided running wheels for 14 days. We measured exercise capacity, neurogenesis (BrDU+/NeuN+ cells) and post‐training cerebral blood flow (CBF) detected by fMRI. Voluntary distances ran each day did not differ between groups. There was a trend for higher BrDU+/NeuN+ cells/0.1 mm2 in WT mice (WT, 4.8+2.0, skmVEGF‐/‐ 1.8+0.6; p=0.08). CBF in mice breathing 21% or 10% O2 did not differ between groups. Endurance was increased in WT compared to skmVEGF‐/‐ mice post‐training (Pre‐training; WT 80+15 min., skmVEGF‐/‐, 27+5 min., Post‐training; WT 107+21 min., skmVEGF‐/‐, 42+8 min., p<0.05). Speed improved in WT mice with training (Pre‐training; WT 61+2 cm/s, skmVEGF‐/‐, 51+3 cm/s, Post‐training; WT 69+3 cm/s, skmVEGF‐/‐, 61+4 cm/s, p<0.05). These data suggest that myofiber VEGF, independent of CBF, may regulate exercise‐induced neurogenesis.Grant Funding Source: American Heart Association
Impact of biorhythms to athletic performance of kickboxers high skills (706.23)
Authors: Daulenbaev M. , Syzdykova S. , Slivkina N. , Kudashov E. 
Published: June 2021

The purpose is to determine the effect of multi‐day biorhythms to the success of the performance at the kickboxing high qualifications competition. The analysis of the data based on performances in the competition professional kickboxer K. Ustinov (Russia) in 2009‐2010. According to the tables for sports performances in the competitions, multi‐day biorhythms were determined according to the computer program at fights on the “ Biorhythm Windows” BIOW, version v 3.20). Results. We can conclude that won fights by a boxer of high qualifications according to two years of follow‐up was 42.8% in fights by decision, 14.3%‐ knockout, and 56.1% by technical knockout.The influence of multi‐rhythms reflected in the results of the fight match, and it was positive with intellectual rhythm and negative with the physical biorhythms that should be included in training and competitive periods of sportsmen training.Analysis of the data for 2 years fighting performances of boxer Alexei Ustinov allowed to conclude the following: 1.Multi‐day biorhythms have an impact to the outcome of the match and it the biggest with intelligent (r=0,845) and natural biorhythms (r=0,665; r=0,68) with a technical knockouts, and negative (by winning fights by decision) with the physical biorhythms (r=‐0,822).
Actual issues of sports training system (706.24)
Authors: Kudashova L. , Syzdykova S. , Dyusupova R. , Lozbina A. 
Published: June 2021

Further growth in athletic performance should be associated with the revision of the existing system of training and to search the most significant factors determining and limiting athletic performance. The aim of this work is to give scientific and methodological rationale role of functional training athletes in the training process. Methods: analysis of scientific literature, teaching observation, research methods of physical performance volleyball, electrocardiography. The results of the study. Our studies on highly skilled volleyball players showed that the dependences are quite high between the studied parameters regulating heart rhythm, physical performance under different pulse modes 130,150,170 beats per minute, maximum oxygen consumption, alaktat and glycolytic reserves of volleyball players in the preparatory period.It is revealed that aerobic reserves are closely dependent on the performance of regulation of heart rate , stress index , physical performance at the pulse of 130 and 170 beats per minute. It is proved that the physical working capacity at the pulse of 170 beats per minute depends on the level of the MOC and the stress index of cardiac activity, and glycolytic reserves had a close relationship with the level of the heart rate , sympathetic regulation of the body's capacity for work , and when the pulse 150 beats per minute.
Effects of swimming training and estrogen therapy on the vascular reactivity of hypertensive ovariectomized rats: role of renin angiotensin system (706.7)
Authors: Abreu Glaucia , Bissoli Nazare , Carvalho Ana Ligia , Gonçalves Erick , Endlich Patrick 
Published: June 2021

Effects of swimming training and estrogen therapy on the vascular reactivity of hypertensive ovariectomized rats: role of renin angiotensin system Glaucia R Abreu, Nazare S Bissoli, Ana Ligia R Carvalho, Erick Roberto C Gonçalves, Patrick W Endlich: Health Science Center, Federal University of Espirito Santo, Brazil Several studies showed up regulation of Renin Angiotensin System (RAS) after menopause and the ability of physical training in reduces cardiovascular risk factors. The aim of this study was to analyze the effects of swimming training (eight weeks) and estrogen therapy (5 mg of 17β‐Estradiol, s.c.) on vascular reactivity and the expression of RAS of aorta rings in ovariectomized spontaneously hypertensive rats (SHR). The groups were divided: Sham (S), Ovariectomized (OVX), ovariectomized (OTE2), ovariectomized+swimming ON) and ovariectomized treated with E2 plus swimming (OE2+N). The systolic blood pressure was measured after the animals were sacrificed and blood was collected to measure Angiotensin II plasma levels by radioimmunoassay. Aorta reactivity we evaluated in response to Ang II and Angiotensin‐(1‐7) and RAS proteins expression were made by Western Blotting method. Both exercise and E2 increased Ang II plasma levels. However, the systolic blood pressure was attenuated by treatments. The OVX group showed increase in the constrictor response to Ang II and decrease dilatator response to Ang (1‐7), that was reverted by swimming training or E2 therapy associated to swimming. Moreover, ON and OE2+N groups showed increase in the AT2 and Mas receptor expression. On the other hand, the ON showed increase in the superoxide dismutase (SOD) anti‐oxidant enzyme and only the groups treated with E2 showed increase on eNOS expression. Then both swimming training and E2 treatment may play a non‐additive, role in the cardioprotection and the chronic physical exercise can be a feasible alternative in relation to estrogen therapy in post‐menopausal women.Grant Funding Source: Capes;CNPq
Catecholamine responses to central hypovolemia induced by lower body negative pressure and blood loss in humans (707.2)
Authors: Johnson Blair , van Helmond Noud , Curry Timothy , Convertino Victor , Joyner Michael 
Published: June 2021

We tested the hypothesis that the catecholamine response would be similar during lower body negative pressure (LBNP) vs. blood loss (BL). Twelve men underwent randomized LBNP and BL protocols on the same day. LBNP consisted of 5‐minute stages at 0, ‐15, ‐30, and ‐45 mmHg of pressure. The BL protocol included 5 minutes at baseline and then after three stages of 333 ml of whole blood draws (1000 ml total) which were stored for reinfusion. Central venous pressure (CVP) was recorded during each protocol. Blood samples were collected at baseline and at the end of the last stage of each protocol. CVP was greater in LBNP vs. BL at baseline (7.3 ± 0.6 vs. 6.1 ± 0.6 mmHg; P < 0.01) and was lower during LBNP vs. BL (‐0.2 ± 0.6 vs. 1.8 ± 0.8 mmHg; P < 0.01). The increase in epinephrine (EPI) during LBNP (53 ± 7 vs.144 ± 30 pg/ml) and BL (49 ± 7 vs. 103 ± 19 pg/ml; P < 0.01) was similar (P = 0.16). An increase in norepinephrine (NE) during LBNP (148 ± 20 vs. 354 ± 44 pg/ml; P < 0.01) was greater (P < 0.01) than the trend to increase during BL (155 ± 22 vs. 211 ± 29 pg/ml; P = 0.09). Individual slopes of catecholamines vs. CVP were calculated to determine if the responses had similar trajectories between the two protocols. The EPI vs. CVP slope was steeper in LBNP vs. BL (‐13.5 ± 4.6 vs. ‐0.6 ± 0.1 pg/ml/mmHg; P < 0.01). The NE vs. CVP slope was steeper in LBNP vs. BL (‐27.8 ± 5.6 vs. ‐8.7 ± 5.9 pg/ml/mmHg; P = 0.01). LBNP to ‐45 mmHg appears to be a greater sympathetic stressor than 1000 ml of BL.Grant Funding Source: Supported by US Army MRMC Combat Casualty Care Research Program Grant # W81XWH‐11‐1‐0823
Hemorrhagic shock resuscitation using a polymerized hemoglobin oxygen carrier versus whole blood (707.5)
Authors: Ortiz Daniel , Cabrales Pedro 
Published: June 2021

The development of an efficient alternative to blood transfusion to treat severe hemorrhage is of great public health importance, especially in far forward scenarios where blood is not available. Hemoglobin (Hb) based oxygen (O2) carriers (HBOCs) have been developed to address this need. Hemopure® (HBOC‐201, bovine Hb glutamer‐250, OPK Biotech,Cambridge, MA, USA), a polymerized Hb based HBOC, has been approved for clinical use in South Africa and Russia. At the time of its approval, however, few studies aimed to understand Hemopure’s function, administration, and adverse effects compared to blood. We have used intravital microscopy to study the microcirculation hemodynamics (arteriolar and venular diameters and blood flow and functional capillary density (FCD)) and oxygenation outcomes of Hemopure® administration at different Hb concentrations _4, 8, and 12 gHb/dL_ compared to fresh blood transfusion for resuscitation from hemorrhagic shock. Experiments are performed in unanesthetized hamsters instrumented with a skinfold window chamber, subjected to hemorrhage (50% of the blood volume, BV), followed by 1 hour hypovolemic shock and fluid resuscitation (50% of the shed volume). Our results show that fluid resuscitation with Hemopure® or blood restored systemic and microvascular parameters. O2 delivery in the microcirculation was directly correlated with Hemopure® concentration, however,increased vasoconstriction was as well. FCD reflected the balance between enhanced O2 transport and reduced blood flow: 12 gHb/dL of Hemopure® and blood had lower FCD compared to the lower concentrations of Hemopure® (p<0.05). The balance between O2 transport and tissue perfusion can provide superior resuscitation from hemorrhagic shock compared to blood transfusion by using a low Hb concentration of HBOCs relative to blood.Grant Funding Source: Supported by: NIH R01 HL52684, R01 HL064395 and R01 HL062318 and ARMY: W81XWH‐11‐2‐0012
Augmented carotid body chemosensitivity during hyperthermia is blunted with low‐dose dopamine (709.3)
Authors: Thomas Kathryn , Johnson Blair , Schlader Zachary , Amaefuna Steve , Crandall Craig , Joyner Michael 
Published: June 2021

We tested the hypothesis that ventilation (VE) and the hypoxic ventilatory response (HVR) during hyperthermia would be attenuated when carotid body chemosensitivity is blunted by an IV infusion of dopamine (2 µg/kg/min) vs. IV saline. We studied 9 subjects (1 woman, 32 ± 2 years, 25.7 ± 0.7 kg/m2) over two randomized dopamine and saline study visits. We measured VE and HVR (3 minutes at: room air, 16% O2, and 10% O2) at baseline and during normothermia (NORMInf) and hyperthermia (HYPInf) (core temperature 1.2‐1.5°C above baseline) infusion conditions. VE increased during HYPInf vs. NORMInf during dopamine (8.2 ± 0.3 vs. 10.2 ± 1.1 L/min; P = 0.04) and saline (8.9 ± 0.3 vs. 9.7 ± 0.5 L/min; P = 0.04) with no difference between conditions (P = 0.95). HVR during saline increased from baseline (0.30 ± 0.1 L/min/%SaO2; P < 0.01) and NORMInf (0.42 ± 0.1 L/min/%SaO2; P = 0.02) to HYPInf (0.77 ± 0.2 L/min/%SaO2). HVR did not change throughout the dopmaine visit (baseline = 0.38 ± 0.1; NORMInf = 0.27 ± 0.1; HYPInf 0.42 ± 0.1 L/min/%SaO2; P > 0.46). Dopamine HVR was lower than saline during HYPInf (P < 0.01). These data indicate that carotid body chemosensitivity to hypoxia is augmented during hyperthermia and that low dose dopamine was unable to lower normoxic VE during hyperthermia.Grant Funding Source: Supported by NIH R01DK090541 and RO1HL61388