Effects of 8 Weeks of 2S-Hesperidin Supplementation on Performance in Amateur Cyclists

2S-Hesperidin is a flavanone (flavonoid) found in high concentrations in citrus fruits. It has an antioxidant and anti-inflammatory effects, improving performance in animals. This study investigated the effects of chronic intake of an orange extract (2S-hesperidin) or placebo on non-oxidative/glycolytic and oxidative metabolism markers and performance markers in amateur cyclists. A double-blind, randomized, placebo-controlled trial was carried out between late September and December 2018. Forty amateur cyclists were randomized into two groups: one taking 500 mg/day 2S-hesperidin and the other taking 500 mg/day placebo (microcellulose) for eight weeks. All participants completed the study. An incremental test was used to evaluate performance, and a step test was used to measure oxygen consumption, carbon dioxide, efficiency and oxidation of carbohydrates and fat by indirect calorimetry. The anaerobic power (non-oxidative) was determined using Wingate tests (30 s). After eight weeks supplementation, there was an increase in the incremental test in estimated functional threshold power (FTP) (3.2%; p ≤ 0.05) and maximum power (2.7%; p ≤ 0.05) with 2S-hesperdin compared to placebo. In the step test, there was a decrease in VO2 (L/min) (−8.3%; p ≤ 0.01) and VO2R (mL/kg/min) (−8.9%; p ≤ 0.01) at VT2 in placebo. However, there were no differences between groups. In the Wingate test, there was a significant increase (p ≤ 0.05) in peak and relative power in both groups, but without differences between groups. Supplementation with an orange extract (2S-hesperdin) 500 mg/day improves estimated FTP and maximum power performance in amateur cyclists.

Indirect Calorimetry Overestimates Oxygen Consumption in Young Children: Caution is Advised Using Direct Fick Method as a Reference Method in Cardiac Output Comparison Studies

Direct Fick method is considered a standard reference method for estimation of cardiac output. It relies on indirect calorimetry to measure oxygen consumption. This is important as only a minor measurement error in oxygen consumption can result in false estimation of cardiac output. A number of studies have shown that indirect calorimetry overestimates oxygen consumption in adults. The aim of this prospective single center observational method comparison study was to compare the determination of oxygen consumption by indirect calorimetry and reverse Fick method in pediatric patients. Forty-two children mean age 352 days (range 30 to 1303 days) and mean weight 7.1 kg (range 2.7–13.6 kg) undergoing corrective cardiac surgery were included in the study. The mean (standard deviation) oxygen consumption by reverse Fick method was 43.5 (16.2) ml/min and by indirect calorimetry 49.9 (18.8) ml/min (p < 0.001). Indirect calorimetry overestimated the reverse Fick oxygen consumption by 14.7%. Bias between methods was 6.5 (11.3) ml/min, limits of agreement (LOA) − 15.7 and 28.7 ml/min and percentage error of 47.7%. A significant bias and large percentage error indicates that the methods are not interchangeable. Indirect calorimetry and the direct Fick method should be used with caution as a reference method in cardiac output comparison studies in young children.

WRIST-WORN TRI-AXIAL ACCELEROMETER VALIDATION IN YOUNG, MIDDLE-AGED, AND OLDER ADULTS

Purpose: This study evaluated wrist-worn accelerometers for estimating metabolic intensity and classifying activity types across a wide age spectrum. Methods: Participants (n=141, 67% women, aged 20-89 yrs) performed a battery of 31 common daily activities (e.g. washing dishes, walking) in a standardized laboratory setting. A tri-axial accelerometer was worn on the right wrist during each activity whiel a portable metabolic unit was used to measure oxygen consumption (ml/kg/min), which was converted into metabolic equivalents (METs). Random forest analyses estimated metabolic intensity and classified activity type based on seven data features. Resulting estimates were cross-evaluated on a separate sample of 16 participants who performed a sub-set of activities in their home. Results: In the laboratory setting, mean differences between measured and predicted MET value for sedentary (0.36), lifestyle (0.02) and locomotor (0.30) activities were low, but the 95% limits of agreement ranges were relatively large (+/-1.0, +/-1.8, +/-3.1, respectively). Data features were 85%, 88%, and 71% accurate for identifying sedentary, lifestyle and locomotor activities. Prediction equations had an overall mean difference of 0.19 METs (95% limits of agreement = -1.3 to 1.7) when activities were performed at home. Conclusion: Data features extracted from a wrist worn tri-axial accelerometer provide a moderate-to-high group estimate of metabolic intensity and had modest accuracy in identifying activity types across a variety of daily activities. However, significant between person variations were evident. Additional work is needed to refine wrist-worn accelerometers for estimating physical activity type, intensity, duration and frequency across the age spectrum.

P4463The pineal hormone melatonin inhibits doxorubicin-induced mitochondrial dysfunction and apoptosis in cardiomyocytes

Background Heart failure (HF) is a major end-point of cardiovascular diseases (CVD). The pathogenesis of HF is mostly unresolved but involves metabolic alterations. Treatment of animals and cardiomyocytes with β-adrenergic receptor agonists induces HF. Mitochondrial dysfunction and HF are common complications of anticancer drugs such as doxorubicin (DOX). Melatonin synthesis dramatically decreases with age and in patients with CVD. Purpose The aim of this study was to investigate whether DOX-induced cardiac dysfunction can be attenuated by melatonin. Methods The Seahorse XF analyser was utilised (with the XFp Cell Energy Phenotype kit) to measure oxygen consumption rate [OCR; oxidative phosphorylation (OXPHOS)] and extracellular acidification rate (ECAR; glycolysis) in living rat cardiomyocyte-derived H9c2 cell line. Mono-layers of cells were treated with cardiotoxic drugs [isoproterenol (ISO, 100μM) or DOX (0.1μM)] for 24hr with and without melatonin co-treatment (MEL, 1μM). Cyan ADP flow cytometry was used to examine the anti-apoptotic properties of MEL (1μM) on DOX-treatment (0.5μM, 24hr). Data are given as mean±SEM (n=separate experiments) and analysis was performed using ANOVA and two-tail unpaired Student's T-test, as applicable. Results Isoproterenol-treatment increased peak OCR of H9c2 cells by ∼30% which was inhibited by MEL [CON, 384±17; ISO, 496±33; ISO+MEL, 412±31pmol/min; n=3 (six replicates); CON vs. ISO, p<0.05; ISO vs. ISO+MEL, p<0.05; CON vs. ISO+MEL, p>0.05]. Doxorubicin-treatment decreased OCR by ∼40% which was reversed by MEL [CON, 934±69; DOX, 554±52; DOX+MEL, 858±97pmol/min; n=3 (six replicates); CON vs. DOX, p<0.05; DOX vs. DOX+MEL, p<0.05; CON vs. DOX+MEL, p>0.05]. ISO and DOX significantly increased (∼30%) and decreased (∼25%) ECAR respectively (n=3, p<0.05) which was not inhibited by MEL. Melatonin alone had no significant effect on OCR and ECAR. Melatonin inhibited DOX-induced apoptosis in H9c2 cells [CON, 6.3±0.8%; DOX, 22±1.8%; DOX+MEL, 11±1.7%, n=4 (two replicates); CON vs. DOX, p<0.001; DOX vs. DOX+MEL, p<0.004; CON vs. DOX+MEL, p>0.05]. Conclusions ISO and DOX-treatment induced mitochondrial dysfunction in H9c2 cells by alteration of OXPHOS and glycolysis; changes in OXPHOS were prevented by MEL. These data indicate that DOX-induced apoptosis in cardiac cells may be mediated, at least in part, by OXPHOS dysfunction which was attenuated by MEL treatment.

Growth of Spiny Lobster Panulirus homarus Fed with Moist Diet

Oxygen is a vital parameter in aquaculture activities. The decrease of dissolved oxygen levels in aquaculture media should be highly observed, since very low dissolved oxygen conditions (hypoxia) could negatively affect to the growth and survival of fish. Therefore, research on the condition of hypoxia is very important to be studied. This study was conducted in January-February 2013 at the Laboratorium of Fish Reproductive Physiology, Pukyong National University, South Korea to measure oxygen consumption in tilapia Oreochromis niloticus (total length: 14.2 ± 1.4 cm, weight: 31.3 ± 2.0 g) under normal conditions (normoxia) and hypoxia. Measurement was conducted using respirometer (dimension: 20 × 17,5 × 10 cm; volume: 3,5 L) every 10 minutes during four hours of observation. Experiment was conducted with three replications. The results showed that oxygen consumption of tilapia fingerlings in hypoxia conditions (12.09 ± 3.20 mg O2/kg/h) was lower than normoxia (35.67 ± 4.19 mg O2/kg/h) (P&lt;0.01). Continuous hypoxic conditions could negatively affect fish movements, which could ultimately lead to mortality when dissolved oxygen levels are very low. Meanwhile, the results on determination of critical oxygen levels for tilapia showed a dissolved oxygen range of 1.9 ± 0.5 mg/L

Effects of Hypoxia on Oxygen Consumption of Tilapia Fingerlings (Oreochromis niloticus)

Oxygen is a vital parameter in aquaculture activities. The decrease of dissolved oxygen levels in aquaculture media should be highly observed, since very low dissolved oxygen conditions (hypoxia) could negatively affect to the growth and survival of fish. Therefore, research on the condition of hypoxia is very important to be studied. This study was conducted in January-February 2013 at the Laboratorium of Fish Reproductive Physiology, Pukyong National University, South Korea to measure oxygen consumption in tilapia <em>Oreochromis niloticus</em> (total length: 14.2 ± 1.4 cm, weight: 31.3 ± 2.0 g) under normal conditions (normoxia) and hypoxia. Measurement was conducted using respirometer (dimension: 20 × 17,5 × 10 cm; volume: 3,5 L) every 10 minutes during four hours of observation. Experiment was conducted with three replications. The results showed that oxygen consumption of tilapia fingerlings in hypoxia conditions (12.09 ± 3.20 mg O₂/kg/h) was lower than normoxia (35.67 ± 4.19 mg O₂/kg/h) (P&lt;0.01). Continuous hypoxic conditions could negatively affect fish movements, which could ultimately lead to mortality when dissolved oxygen levels are very low. Meanwhile, the results on determination of critical oxygen levels for tilapia showed a dissolved oxygen range of 1.9 ± 0.5 mg/L.

Abstract 232: Bendavia, a Novel Mitochondria Targeting Peptide, Improves Mitochondrial Function in Circulating Blood Monocytes From Dogs With Chronic Heart Failure

Background: Mitochondrial (MITO) function is abnormal in heart failure (HF) as evidenced by reduced MITO respiration and rate of ATP synthesis. We showed that MITO dysfunction can be normalized in HF dogs after therapy with Bendavia (BEN), a novel MITO targeting peptide. This study tested the hypothesis that BEN will also reverse abnormalities of MITO function present in blood monocytes (MCs) of HF dogs. Methods: Blood samples obtained from 6 normal (NL) dogs and 6 dogs with coronary microembolizations-induced HF (LV ejection fraction ~30%) were used to isolate MCs by sequential Ficoll and Percoll density gradients. An XFe/XF96 analyzer (Seahorse Bioscience) was used to measure oxygen consumption rates (OCR) in MCs in the presence and absence of 1 μM oligomycin, 0.5 μM FCCP, or 1 μM each rotenone and antimycin. MITO proton leak, maximal respiration (MAXresp) and spare respiratory capacity (SRC) were measure in the presence and absence of 0.1, 1.0 and 10 μM concentrations of BEN and results expressed in pmols OCR/min/μg protein. Results: Proton leak, MAXresp and SRC were abnormal in MCs of HF dogs compared to NL. Incubation with BEN had no effect on measures of MCs MITO function of NL dogs but nearly normalized MITO function of MCs of HF dogs as evidenced by a dose-dependent increase MAXresp and SRC and dose-dependent decrease in proton leak (Table). Conclusions: MITO function is abnormal in blood MCs of HF dogs. BEN had no effect on MITO function of MCS from NL dogs but normalized MITO function in MCs from HF dogs. These findings support the use of circulating blood MCs as means of assessing MITO dysfunction in HF and as a marker of potential benefits derived from treatment with MITO targeted therapies.

Combined effect of body weight, temperature and salinity on shrimp Litopenaeus vannamei oxygen consumption rate

Aiming to optimize the calculations of mechanical aeration requirements in Litopenaeus vannamei marine shrimp cultures, oxygen consumption was quantified in combined conditions of temperature (20, 25 and 30ºC) and salinity (1, 13, 25 and 37 ‰) at three body weights (2, 6 and 12 g) for juvenile L. vannamei. To measure oxygen consumption, shrimps were placed in a semi-open respirometry system. Results demonstrate that temperature, salinity, shrimp size and the interaction of these parameters significantly influence the specific oxygen consumption (mg O2 g-1 h-1). The 2-g shrimp perhaps suffered osmotic stress and consumed more oxygen at salinity 37 ‰, whereas 6 and 12-g shrimp suffered such stress at salinity 1 ‰. At 25 and 30ºC oxygen consumption was more stable at salinities 13 and 25 ‰ for all groups. At 20ºC and salinity below 25 ‰ oxygen consumption was higher, possibly due to the reduced hyperosmoregulatory ability in lower temperatures. The resulting regression equations allowed the calculation of L. vannamei shrimp oxygen consumption at the temperatures, salinities and sizes tested in this study. The equations can be used for the estimation of the environmental capacity and also the mechanical aeration requirements to secure ideal levels of oxygen in L. vannamei culture systems.