bluuebunny/crossref_metadata_2025_split huggingface dataset:
Altered coronary vascular function in a mouse model of Hypertrophic Cardiomyopathy
Authors: Muller‐Delp Judy Marie , Maraj Joshua J. , Huke Sabine 
Published: June 2021

Mice with the troponin T (TnT)‐I79N mutation, which is associated with hypertrophic cardiomyopathy in humans, develop arrhythmias during stress despite the absence of an overt anatomical substrate. The arrhythmias are linked to the occurrence of energy deprived regions in the ventricular myocardium, but the underlying mechanism is not completely understood. Preliminary data indicate that vascular dysfunction that results in ischemia is at least in part responsible for the regional energy deprivation. In this study we are investigated whether cardiac microvascular function is altered in TnT‐I79N mice.We isolated resistance arterioles from the hearts of troponinTnT‐I79N mice and non‐transgenic mice, and evaluated vasodilatory responses to endothelium‐dependent (flow) and endothelium‐independent (DeaNONOate) stimuli. Contractile responses to pressure (myogenic responsiveness) and endothelin were also assessed. Flow‐induced vasodilation was significantly increased in coronary arterioles from TnT‐I79N mice (maximal dilation 81±9%) as compared to coronary arterioles from non‐transgenic mice (maximal dilation 58±9%). Endothelium‐independent responses to DeaNONOate were not altered in coronary arterioles from TnT‐I79N mice. Contractile responses to endothelin were significantly reduced in arterioles from TnT‐I79N mice (44±6% in TnT‐I79N arterioles vs. 64±5% in non‐transgenic arterioles; P<0.01). Myogenic responses to increasing transmural pressure were not altered in arterioles from TnT‐I79N mice.Altogether, these data indicate heightened responsiveness of the endothelium of coronary resistance arterioles in the hearts of TnT‐I79N mice. Since the mutant protein is exclusively expressed in the cardiomyocytes, this indicates an indirect effect of the cardiomyocytes on the vasculature.Support or Funding InformationNIH R01 to Sabine HukeThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Improvement of mitochondrial function in human atrial tissue by remote ischemic conditioning
Authors: Kleinbongard Petra , Gedik Nilguen , Frey Ulrich , Zandi Afsaneh , Thielmann Matthias , Jakob Heinz , Peters Jürgen , Kamler Markus , Heusch Gerd 
Published: June 2021

IntroductionRemote ischemic preconditioning (RIPC), repeated cycles of brief limb ischemia/reperfusion, attenuates postoperative troponin release in patients undergoing surgical coronary revascularization and improves clinical outcome in some, but not all studies. Mitochondria are the end‐effectors of cardioprotection by local ischemic conditioning maneuvers in experimental studies. Here, we now analyzed mitochondrial function in response to RIPC in human atrial tissue.MethodsPatients undergoing elective surgical coronary revascularization under isoflurane anesthesia were randomized to RIPC by 3× 5 min/5 min upper arm blood pressure cuff inflation/deflation or placebo (n=30/30), and their right atrial appendages were harvested prior to ischemic cardioplegic arrest. Cardioprotection was reflected by a 14% decrease with RIPC vs. placebo in the area under the curve of serum troponin I/T concentrations over 72 h after surgery. Mitochondria were isolated from the atrial tissue (n=10/10). Mitochondrial function, i.e. mitochondrial respiration, adenosine triphosphate (ATP) production, reactive oxygen species (ROS) production and calcium retention capacity (CRC) to estimate mitochondrial permeability transition pore (mPTP) opening, was measured at physiological temperature of 37°C. Data are given as mean±SEM.ResultsAssociated with the observed cardioprotection in patients, mitochondrial function was improved by RIPC. Basal respiration was not different between RIPC and placebo. ADP‐stimulated complex I respiration was significantly greater with RIPC than with placebo. Mitochondrial complex IV respiration and maximal oxygen uptake of uncoupled mitochondria were not different between RIPC and placebo, reflecting an equal loading of viable mitochondria (Figure 1A). The mitochondrial ATP production (Figure 1B) was greater whereas mitochondrial ROS production (Figure 1C) was less with RIPC than with placebo. CRC of mitochondria (Figure 1D) was improved with RIPC in comparison to placebo, with and without cyclosporine A.ConclusionIn human myocardium, mitochondria are an intracellular target of protection by RIPC.Support or Funding InformationSupported by: German Research Foundation (SFB 1116 B8)This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
The Acute Chronotropic Effect of the Uremic Metabolite, Trimethylamine‐N‐Oxide (TMAO), on Mouse Cardiac Muscle
Authors: Sanborn David Michael , Oakley Carlee , Grillo Michael , Vallejo Julian , Rafie Nikita , Wacker Michael 
Published: June 2021

BackgroundWhile it is understood that patients with chronic kidney disease (CKD) have an increased propensity for developing cardiovascular disease, the exact mechanisms remain unclear. Growing evidence suggests that the gut microbiome and its byproducts, such as TMAO, may be important contributors to this pathologic process. This uremic metabolite is cleared through renal excretion, which is compromised in CKD patients. Therefore, CKD patients often possess elevated plasma levels of this substance. In a previous study, we found that TMAO at pathological concentrations directly increases cardiac contractility in isolated, paced hearts. In this study, we sought to determine if TMAO also has chronotropic effects on isolated, spontaneously beating mouse hearts.MethodsWhole mouse hearts were extracted from anesthetized CD1 adult mice and subsequently connected to a force transducer and bubbled with oxygen inside an organ bath. The atria and sinoatrial node were kept intact to allow for spontaneous beating without artificial pacing. Changes in heart rate (in beats per minute) were measured after treatment with TMAO (3,000 μM) or vehicle (Ringer's solution). Additionally, calcium imaging was performed on cultured spontaneously beating embryonic rat cardiomyocytes. Intracellular Ca2+ responses in rat primary cardiomyocytes were measured with the fluorescent Ca2+ indicator Fura‐2 AM in response to vehicle and TMAO (3,000 uM).ResultsAverage beating frequency (in beats per minutes) of isolated hearts increased by 27% following treatment with 3,000 μM TMAO (P < 0.05, n =3) while there was no change with vehicle. Regarding isolated myocytes, TMAO was found to have a direct chronotropic effect as it increased beating frequency (as measured by calcium waves) by 13% compared to vehicle treatment (P < 0.05, n =4–5).ConclusionsIn addition to our previously described inotropic effects in the mouse heart, pathologic concentrations of TMAO also have a direct and positive chronotropic effect. The direct effects we have observed on the heart may increase cardiac output in early stages of CKD. However, cardiac remodeling as a result of increased beating frequency and contractility may have pathologic consequences in those with chronic disease. Further research is needed in order to elucidate the effect that TMAO has on cardiovascular function and pathology during CKD.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Moderate exercise training under constant light condition amplifies inflammatory signals through disruption of splenic clock mechanism in osteoarthritic animals
Authors: Hong Yunkyung , Hossain Mohammad Farhad , Hong Yonggeun 
Published: June 2021

Physical exercise has been recommended for osteoarthritic(OA) patients, the effects of which depends on exercise protocol. Here, we determined whether the benefits of exercise are influenced by lighting condition in the OA rats. Moderate treadmill exercise(Ex) was performed for 4 weeks at ZT14 under 12:12hr light‐dark(L/D) as well as constant light(LL). Intervention was applied for 30 min on 5 days/week. Splenic Cry1 expression was suppressed in the trained rats under constant light condition, leading to upregulation of proinflammatory cytokines mRNA. Moreover, TNFα level in serum was higher in the LL+Ex group than the L/D+Ex group. Constant light combined with exercise exacerbated primary cartilage lesion through an increase of catabolic molecules as well as a transcriptional suppression of anabolic factors. The level of synovial RANKL protein was elevated in the LL+Ex group, leading to loss of tibial trabeculae. And increased joint diameter was not recovered in the exercise‐trained rats under LL condition. Exercise training under constant lighting condition enhanced activation of catabolic machinery in soleus as well as gastrocnemius muscle. Treatment of proinflammatory cytokines disrupted rhythmic expression of catabolic enzymes in C2C12‐derived myotubes. Taken together, lighting condition might be a considerable environmental factor to obtain exercise‐induced benefits.Support or Funding InformationFunding: NRF‐2015R1C1A2A01055691, NRF‐2017R1A2A2A01067169, KGM4611714This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Left Ventricular Strain and Strain Rate Responses to Submaximal Exercise in Prostate Cancer Patients Treated with Androgen Deprivation Therapy
Authors: Post Hunter K. , Lovoy Garrett M. , Banister Heather R. , Sutterfield Shelbi L. , Caldwell Jacob T. , Ade Carl J. 
Published: June 2021

IntroductionAndrogen Deprivation Therapy (ADT), like that used to treat prostate cancer patients, increases cardiovascular disease risk and mortality. Administration of ADT impairs left ventricular mechanics in animal models, however, it remains poorly understood how ADT influences cardiac function in human prostate cancer patients. Therefore, the aim of the current investigation was to non‐invasively measure left ventricular mechanics at rest and during submaximal exercise in prostate cancer patients with and without a history of ADT treatment. We hypothesized that change in left ventricular strain, strain rate, and tissue velocities during the rest‐to‐exercise transition would be impaired in those with a history of ADT treatment compared to those with no prior ADT.MethodsTo date, 7 prostate cancer patients (66 ± 7 yrs) have completed the experimental protocol. Cancer subjects (n=3 treated with ADT; n=4 no history of ADT) performed echocardiographic measurements at rest and during a supine submaximal cycling exercise to a target heart rate of 100 beats/min. Tissue Doppler echocardiography was used to measure myocardial tissue velocities in systole (S′) and early diastole (E′). In addition, myocardial deformation was assessed via measurements of left ventricular strain (S), and strain rate (SR) from the mid‐interventricular septum. Systolic and diastolic reserve indices were calculated from myocardial velocities.ResultsThe change in systolic S from rest to exercise was significantly different between groups (ADT: 2.8 ± 1.5 %; Non‐ADT: −3.3 ± 4.2 %; p=0.03). The change in systolic SR from rest to exercise was significantly different between groups (ADT: −0.037 ± 0.6 1/s; Non‐ADT: −0.23 ± 0.15 1/s; p=0.03). There were no changes observed between groups from rest to exercise in early diastolic filling SR (ADT: 0.74 ± 0.47 1/s; Non‐ADT: 0.86 ± 0.35 1/s; p=0.35), systolic reserve index (ADT: 2.27 ± 0.07; Non‐ADT: 0.86 ± 1.4; p=0.07), and diastolic reserve index (ADT: −5.05 ± 2.1; Non‐ADT: −2.9 ± 2.5; p=0.14). There were also no significant changes observed between groups in S′ (ADT: 0.034 ± 0.033 cm s−1; Non‐ADT: 0.0017 ± 0.02 cm s−1; p=0.09), and E′ (ADT: 0.046 ± 0.025 cm s−1; Non‐ADT: 0.033 ± 0.033 cm s−1; p=0.31).ConclusionThis preliminary evidence suggests that ADT in prostate cancer patients significantly impairs left ventricular function as determined by changes in systolic SR and S in response to submaximal exercise. These findings may hold significant value beyond the basic characterization of left ventricular function, in particular as part of a risk‐stratification strategy in prostate cancer patients receiving ADT.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Heart Rate Alters but Does Not Improve Calorie Predictions in Fitbit Activity Monitors
Authors: Vusich John W. , Mitrzyk John , Wiersma Matthew , Montoye Alexander HK. 
Published: June 2021

Consumer‐based activity monitors such as Fitbit use accelerometers and possibly heart rate (HR) in proprietary prediction models to estimate calories (kcals). In theory, including HR in a kcal prediction model should improve kcal prediction since HR is a physiologic measure of effort; however, this has not yet been tested for consumer‐based activity monitors.PURPOSETo determine if Fitbits measuring HR estimate kcals differently than Fitbits without HR.METHODSParticipants (n=23) performed nine activities in the laboratory for five minutes each, split into four groupings (G1: sitting, standing, cycling 50–150W, G2: level and inclined (10%) walking at 2.5 miles/hour, G3: level and inclined (10%) walking at 2.5–3.2 miles/hour, G4: level and inclined (3%) jogging at 5–10 miles/hour). These groupings were specifically designed to elicit similar steps for activities but different HR and kcal expenditure. Participants wore five Fitbits, three on the dominant wrist (proximal to distal: Blaze, Alta HR, Alta) and two on the non‐dominant wrist (Charge HR proximal to Flex 2). Three Fitbits (Blaze, Charge HR, Alta) assessed steps, HR, and kcals, and two Fitbits (Alta, Flex2) assessed steps and kcals during each activity. Estimates from the Fitbits were compared to criterion measures, between Fitbits measuring HR and Fitbits without HR, and for each activity grouping, using repeated measures analysis of variance.RESULTSFitbits with HR had significantly higher kcal predictions (10.5–23.8% higher, p<0.05) during inclined walking/jogging than level walking/jogging in groupings G2‐G4, whereas Fitbits without HR had similar kcal estimates between level and inclined activities; this finding indicates that Fitbits with HR were responsive to a change in exercise intensity during inclined walking/jogging compared to level walking/jogging. For G1, estimated kcals were not different between sitting and standing but were significantly higher for cycling in all monitors. The increase in estimated kcal expenditure was much greater in the three Fitbits measuring HR (589–708% increase from sitting/standing to cycling) than in the two Fitbits without HR (90–139% increase from sitting/standing to cycling). However, mean absolute percent error for kcal predictions for Fitbits measuring HR (33.7–38.3%) were similar to Fitbits without HR (32.4–36.6%) overall and for most individual activities.CONCLUSIONFitbits measuring HR do use HR when predicting kcals during physical activity. However, kcal prediction accuracies were similarly poor compared to Fitbits not measuring HR. Individuals looking to use consumer‐based activity monitors to track kcal expenditure should do so cautiously.Support or Funding InformationAlma College CORE Research ProgramThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Circadian Rhythm Does Not Alter the Sweating Response to Exercise in Thermoneutral and Warm Ambient Temperatures
Authors: Ravanelli Nicholas , Imbeault Pascal , Jay Ollie 
Published: June 2021

The present study sought to determine whether the diurnal fluctuation in core temperature alters the sweating response to exercise in thermoneutral (23°C) and warm (33°C) environments. Six healthy males exercised on a semi‐recumbent ergometer at a fixed evaporative requirement for heat balance (200W/m2) for 60 min at two different times of day and two ambient temperatures matched for absolute humidity (1.3 kPa); i) 0800h/23°C, ii) 0800h/33°C, iii) 1600h/23°C, and iv) 1600h/33°C. Esophageal temperature (Tes), mean body temperature (Tb), local sweat rate (LSR) measured at the arm and upper back, and whole body sweat loss (WBSL) were measured. Resting absolute Tes was higher at 1600h compared to 0800h at 23°C (0800h: 36.7±0.2°C, 1600h: 36.9±0.2°C; P=0.04) and 33°C (0800h: 36.6±0.2°C, 1600h 36.9±0.2°C; P=0.005). Similarly, end‐exercise (steady‐state) absolute Tes was higher at 1600h relative to 0800h at 23°C (0800h: 37.4±0.2°C, 1600h: 37.6±0.2°C; P=0.04) and 33°C (0800h: 37.0±0.2°C, 1600h 37.2±0.2°C; P=0.01). However the change in Tes was similar irrespective of the time of day at both 23°C (0800h: 0.7±0.1°C, 1600h: 0.7±0.2°C; P=0.37) and 33°C (0800h: 0.4±0.1°C, 1600h: 0.3±0.1°C; P=0.35). Further, mean steady‐state LSR of arm and back after 60 min of exercise was similar irrespective of time at both 23°C (0800h: 0.66±0.06 mg/cm2/min, 1600h: 0.65±0.13 mg/cm2/min; P=0.74) and 33°C (0800h: 0.62±0.11 mg/cm2/min, 1600 h: 0.58±0.11 mg/cm2/min, P=0.50). Likewise, WBSL at steady‐state (46 to 60 min) was similar between morning and afternoon trials at 23°C (0800h: 156±28 g, 1600h: 162±36 g; P=0.38) and 33°C (0800h: 147±29 g, 1600h: 158±34 g, P=0.55). While sweating commenced prior to exercise in 33°C, the onset threshold for sweating occurred at a higher Tb at 1600h compared to 800h at 23°C (0800h: 35.6±0.1°C, 1600h 35.9±0.2°C; P=0.03), however the change in Tb was similar at 23°C regardless of time of day (0800h: 0.14±0.07°C, 1600h 0.17±0.12°C; P=0.47). Lastly, sudomotor thermosensitivity (LSR‐Tb) was similar at both 23°C (0800h: 0.80±0.26 mg/cm2/min/°C, 1600h: 0.82±0.30 mg/cm2/min/°C; P=0.80) and 33°C (0800h: 0.81±0.18 mg/cm2/min, 1600h: 0.90±0.40 mg/cm2/min, P=0.87). Taken together, preliminary data suggests the difference in absolute core temperature (~0.3°C) associated with diurnal fluctuation does not alter the sweating response at a fixed evaporative requirement for heat balance in both thermoneutral and warm conditions.Support or Funding InformationN.R. was supported by an NSERC Postgraduate Scholarship‐Doctoral and a University of Ottawa Excellence Scholarship.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Crude oil impairs heart cell function in the mahi‐mahi (Coryphaena hippurus)
Authors: Heuer Rachael M. , Shiels Holly A. , Galli Gina L. J. , Cox Georgina K. , Stieglitz John D. , Benetti Daniel D. , Grosell Martin , Crossley Dane A. 
Published: June 2021

The Deepwater Horizon oil spill of 2010 released millions of barrels of crude oil into the Gulf of Mexico. This was particularly concerning for many ecologically and economically important pelagic fish species, since the spill overlapped spatially and temporally with their spawning seasons. Pelagic fish have been shown to be sensitive to the cardiotoxic effects of oil across species, life stages, and levels of organization. Recent work on the mahi‐mahi (Coryphaena hippurus) has revealed that exposure to environmentally‐relevant crude oil concentrations negatively impacts animal performance, causing reductions to maximal sustained swimming speed and maximal metabolic rate. Subsequent in‐situ studies on the heart have revealed a ~40% reduction in cardiac output in oil‐exposed mahi, which explains reduced performance. Although cardiotoxic effects have been widely reported, the mechanisms underlying these impairments remain understudied. In the present study, we examined the impacts of crude oil on isolated mahi ventricular cardiomyocyte contractility to better understand these mechanisms. Contractility and other mechanical aspects of cellular contraction were measured using an IonOptix cell recording system, which uses sarcomere shortening as proxy for contractility. The first objective was to examine cardiomyocyte contractility over range of crude oil exposures. The second objective was to examine the impacts of crude oil contractility over a range of stimulation frequencies representative of heart rates observed in mahi (~100–180 beats per minute). Exposure to crude oil was found to significantly reduce heart cell contractile function, but was not found to be dose‐dependent in the range of tested concentrations (3.0, 6.4, and 12.9 μg l−1 ∑50 PAH). Crude oil was also found to impair contractility over a range of stimulation frequencies (1.5–3.0 Hz; 3.6 μg l−1 ∑50 PAH). Since the oil concentration needed to impair function at the cellular level was much lower than what has been observed to induce impairments to animal performance, the role of circulating catecholamines as a potential protective mechanism during oil exposure will also be explored. This research was made possible by a grant from The Gulf of Mexico Research Initiative. Grant No: SA‐1520Support or Funding InformationGulf of Mexico Research Initiative. Grant No: SA‐1520This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Relationship between Dietary Profile and Blood Glucose Concentration in Birds
Authors: Basile Anthony J. , Jarrett Catherine L. , Sweazea Karen L. 
Published: June 2021

Diet throughout the life history of a species may contribute to their unique fuel physiology. Aves are unique in the animal kingdom as they evolved to have the highest plasma glucose (Pglu) concentration of any animal class. While Pglu is negatively correlated with body mass in Aves, there is considerable variation in Pglu among birds of similar body mass. A potential explanation for this variability may be dietary differences. Therefore, the goal of this study was to determine whether Pglu is related to diet profile (herbivore, omnivore, insectivore, frugivore/nectarivore, carnivore, granivore, and piscivore) within and across animal classes. Data on diet profile, Pglu, and body mass were obtained for 375 species of animals (Amphibia, n = 6; Aves, n = 163; Mammalia, n = 121, Reptilia, n = 85) housed at The Phoenix Zoo in Arizona. Data were analyzed using one‐way ANOVA and Dunn's post hoc analyses with p‐values of < 0.05 considered statistically significant. Data from captive animals are advantageous as the dietary profile and life history of each animal is known, thereby minimizing the unpredictability of wildlife. Consistent with prior studies, Aves maintained the highest Pglu among vertebrates (16.20 mM/L ± 0.26, p < 0.05). Within Aves, animals consuming either insectivorous or granivorous diets had the highest Pglu (p < 0.05). For insectivores, the high glucose concentrations are likely attributed to de novo hepatic and renal gluconeogenesis. Similarly, within Reptilia insectivorous animals maintain the highest Pglu (p < 0.05). No significant differences were found between dietary profile in Mammals (p > 0.05). Understanding the relationship between dietary profiles and Pglu may contribute to our understanding of why Aves evolved to have the highest glucose concentrations among vertebrates.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.