500 Late-Breaking: Heart Rate During Exercise Is Positively Correlated with State IV Mitochondrial Respiration in the Equine Skeletal Muscle

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 105-106
Author(s):  
Mia Y Kawaida ◽  
Oh-Sung Kwon ◽  
Ahram Anh ◽  
Amanda S Reiter ◽  
Nicole M Tillquist ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Heart Rate ◽  
Oxidative Phosphorylation ◽  
Mitochondrial Respiration ◽  
Recovery Period ◽  
Proton Leak ◽  
Semitendinosus Muscle ◽  
Exercise Tests ◽  
Cardiac Responses ◽  
The Relationship

Abstract Mitochondria are critical for oxidative phosphorylation in skeletal muscle, especially in athletic species such as the horse. Mitochondrial respiration increases with physical exercise, but the relationship between mitochondrial respiration and cardiovascular functions are not well described in the horse. The objective of this study was to determine if there is a relationship between heart rate (HR) during and after submaximal exercise tests (SETs) and skeletal muscle mitochondrial respiration in polo ponies. We hypothesized that horses with greater maximum HR and average HR during the exercise tests would have greater mitochondrial respiration in skeletal muscle. Twelve fit polo ponies (14.8 ± 1.7 years old, 10 mares and 2 geldings) were equipped with Polar equine heart rate monitors (Polar Electro Inc., Lake Success, NY) and underwent 26-minute SETs designed to mimic a polo chukker followed by a 30-minute recovery period. Muscle biopsy samples from the semitendinosus muscle were taken 2 weeks prior to the SET to determine mitochondrial oxygen consumption using the Oroboros O2k high-resolution respirometer (Oroboros Instruments, Innsbruck, Austria). Data were analyzed using the PROC CORR procedure (SAS Inst. Inc., Cary, NC). Correlations were considered strong at r > 0.6 and significant at P < 0.05. Maximum HR during SET and state IV respiration were positively correlated (P = 0.02, r = 0.68). Average HR during SET and state IV respiration were also positively correlated (P = 0.01, r = 0.72). However, correlations between maximum and average HR and state III respiration were not as strong (P ≥ 0.05, r < 0.6). These data suggest that state IV mitochondrial respiration (proton leak) in equine skeletal muscle may impact cardiac responses to high-intensity exercise. Horses with higher HR during exercise may have less efficient oxidative phosphorylation, resulting in earlier fatigue and/or greater formation of reactive oxygen species resulting from proton leak.

Blunted Heart Rate Recovery to Spontaneous Nocturnal Arousals in Short Sleeping Adults

2021 ◽  
Author(s):  
Jeremy A. Bigalke ◽  
Ian M. Greenlund ◽  
Jennifer R. Nicevski ◽  
Carl A. Smoot ◽  
Benjamin Oosterhoff ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Recovery ◽  
Recovery Period ◽  
Sleep Time ◽  
Cardiovascular Complications ◽  
Female Age ◽  
Cardiac Reactivity ◽  
Electrocardiogram Ecg ◽  
The Relationship ◽  
At Home

Chronic insufficient sleep is a common occurrence around the world, and results in numerous physiological detriments and consequences, including cardiovascular complications. The purpose of the present study was to assess the relationship between habitual total sleep time (TST) measured objectively via at-home actigraphy and heart rate (HR) reactivity to nocturnal cortical arousals. We hypothesized that short habitual TST would be associated with exaggerated cardiac reactivity to nocturnal cortical arousals. Participants included in 35 healthy individuals (20 male, 15 female, age: 24 ± 1, BMI: 27 ± 1 kg/m2), and were split using a median analysis into short (SS; n = 17) and normal sleeping (NS; n = 18) adults based on a minimum of 7 days of at-home actigraphy testing. All participants underwent a full overnight laboratory polysomnography (PSG) testing session, including continuous HR (electrocardiogram, ECG) sampling. HR reactivities to all spontaneous cortical arousals were assessed for 20 cardiac cycles following the onset of the arousal in all participants. Baseline HR was not significantly different between groups (P > .05). Spontaneous nocturnal arousal elicited an augmented HR response in the SS group, specifically during the recovery period [F (4.192, 134.134) = 3.413, p = .01]. There were no significant differences in HR reactivity between sexes [F (4.006, 128.189) = .429, p > .05]. These findings offer evidence of nocturnal cardiovascular dysregulation in habitual short sleepers, independent from any diagnosed sleep disorders.

Effect of hyperthermia and acidosis on equine skeletal muscle mitochondrial oxygen consumption

2020 ◽  
pp. 1-10
Author(s):  
M.S. Davis ◽  
M.R. Fulton ◽  
A. Popken
Keyword(s):  
Skeletal Muscle ◽  
Oxygen Consumption ◽  
Oxidative Phosphorylation ◽  
Muscle Fatigue ◽  
Mitochondrial Function ◽  
Mitochondrial Respiration ◽  
Complex I ◽  
Mitochondrial Oxygen Consumption ◽  
Biochemical Basis ◽  
Complex Ii

The skeletal muscle of exercising horses develops pronounced hyperthermia and acidosis during strenuous or prolonged exercise, with very high tissue temperature and low pH associated with muscle fatigue or damage. The purpose of this study was to evaluate the individual effects of physiologically relevant hyperthermia and acidosis on equine skeletal muscle mitochondrial function, using ex vivo measurement of oxygen consumption to assess the function of different mitochondrial elements. Fresh triceps muscle biopsies from 6 healthy unfit Thoroughbred geldings were permeabilised to permit diffusion of small molecular weight substrates through the sarcolemma and analysed in a high resolution respirometer at 38, 40, 42, and 44 °C, and pH=7.1, 6.5, and 6.1. Oxygen consumption was measured under conditions of non-phosphorylating (leak) respiration and phosphorylating respiration through Complex I and Complex II. Data were analysed using a one-way repeated measures ANOVA and data are expressed as mean ± standard deviation. Leak respiration was ~3-fold higher at 44 °C compared to 38 °C regardless of electron source (Complex I: 22.88±3.05 vs 8.08±1.92 pmol O2/mg/s), P=0.002; Complex II: 79.14±23.72 vs 21.43±11.08 pmol O2/mg/s, P=0.022), resulting in a decrease in efficiency of oxidative phosphorylation. Acidosis had minimal effect on mitochondrial respiration at pH=6.5, but pH=6.1 resulted in a 50% decrease in mitochondrial oxygen consumption. These results suggest that skeletal muscle hyperthermia decreases the efficiency of oxidative phosphorylation through increased leak respiration, thus providing a specific biochemical basis for hyperthermia-induced muscle fatigue. The effect of myocellular acidosis on mitochondrial respiration was minimal under typical levels of acidosis, but atypically severe acidosis can lead to impairment of mitochondrial function.

scholarly journals Evaluación del Talk Test como método para estimar la intensidad del ejercicio en niños sanos (Evaluation of the Talk Test as a method to estimate exercise intensity in healthy children)

Retos ◽  
2019 ◽  
pp. 303-308
Author(s):  
Danissa Hernández ◽  
Natalia Pacheco ◽  
Issis Poblete ◽  
Héctor Tórres ◽  
Iván Rodríguez-Núnez
Keyword(s):  
Heart Rate ◽  
Exercise Intensity ◽  
Healthy Children ◽  
Exercise Tests ◽  
Indirect Methods ◽  
A Value ◽  
Significant Difference ◽  
Intensity Of Exercise ◽  
Incremental Step ◽  
The Relationship

Introducción: La frecuencia cardíaca (FC) ha sido tradicionalmente utilizada para regular la intensidad del ejercicio, sin embargo, presenta limitaciones para su cuantificación sin un monitor cardiaco. En consecuencia, métodos indirectos, como el Talk Test (TT), han sido validados en adultos, no así en población infantil. El objetivo de este estudio fue determinar la relación entre el TT y los métodos objetivos para cuantificar la intensidad del ejercicio en niños sanos chilenos. Métodos: Se consideró a niños sanos de ambos géneros entre 8 y 12 años. Los sujetos realizaron dos pruebas de ejercicio incremental en escalón separadas por 7 días. El TT se incorporó en una de las dos pruebas aleatoriamente. Se midió la FC, percepción del esfuerzo (PE) y carga de trabajo, cada un minuto durante la prueba. Se comparó la FC, PE y carga de trabajo entre la respuesta positiva (TT+/+), equívoca (TT+/-) y negativa (TT-/-) del TT. Adicionalmente, se determinó la confiabilidad de los parámetros cardiorrespiratorios durante el TT. Un valor de p<.05 se consideró significativo. Resultados: Ingresaron 48 sujetos, edad 9.7±1.1 años. Existió diferencia significativa en los parámetros cardiorrespiratorios entre las respuestas del TT (p<.0001). El % de la FC máxima en TT+/+ fue 72.2 ± 8.2, en TT+/- fue 87.9 ± 8.1 y en TT-/- fue 92.0 ± 7.5%. La confiabilidad de los parámetros cardiorrespiratorios durante el TT fue regular a excelente en ambos géneros. Conclusiones: El TT se relacionó con los parámetros cardiorrespiratorios para regular la intensidad del ejercicio en niños sanos.Abstract. Introduction: Heart rate (HR) has traditionally been used to regulate the intensity of exercise; however, its measurement is limited in the absence of a heart rate device. Consequently, indirect methods, such as the Talk Test (TT), have been validated in adults, yet not in children. The objective of this study was to determine the relationship between TT and objective methods to quantify the intensity of exercise in healthy Chilean children. Methods: Healthy children of both genders aged between 8 and 12 years old were considered for the study. The participants performed two incremental step exercise tests separated by 7 days. The TT was incorporated in one of the two tests randomly. The HR, effort perception (EP) and workload were measured every one minute during the test. HR, EP and workload were compared by positive (TT + / +), equivocal (TT +/-), and negative (TT - / -) response of the TT. Additionally, the reliability of cardiorespiratory parameters during TT was determined. A value of p <0.05 was considered significant. Results: 48 participants aged 9.7 ± 1.1 years old were selected. There was a significant difference in cardiorespiratory parameters between the TT responses (p <.001). The percent of maximum HR in TT + / + was 72.2 ± 8.2%, in TT +/- was 87.9 ± 8.1% and in TT - / - was 92.0 ± 7.5%. The reliability of cardiorespiratory parameters during TT was fair to excellent in both genders. Conclusions: TT was associated to cardiorespiratory parameters to regulate exercise intensity in healthy children.

scholarly journals THE RELATIONSHIP BETWEEN CYTOCHONDRIA AND MYOFIBRILS IN PIGEON SKELETAL MUSCLE

1953 ◽  
Vol 98 (1) ◽  
pp. 81-98 ◽  
Author(s):  
John W. Harman ◽  
Ursula H. Osborne
Keyword(s):  
Skeletal Muscle ◽  
Oxidative Phosphorylation ◽  
Oxidative Metabolism ◽  
Krebs Cycle ◽  
Oxidative Capacity ◽  
Breast Muscle ◽  
Oxidative Enzymes ◽  
Mitochondrial Oxidative Capacity ◽  
The Relationship ◽  
Oxidative Rate

In pigeon breast muscle the mitochondria are the principal site of oxidative metabolism, whereas the myofibrils are incapable of oxidizing intermediates of the Krebs cycle. The mitochondria contain the oxidative enzymes, and the sarcosomes are associated with a factor which accelerates the mitochondrial oxidative rate. The maintenance of myofibrillar contractility and structure is closely correlated with preservation of mitochondrial oxidative capacity and structure. By use of fluoride and dinitrophenol the connection between mitochondrial metabolism and myofibrillar behavior is shown to occur through the process of oxidative phosphorylation.

scholarly journals Effect of pyruvate, lactate and insulin on ATP supply and demand in unpaced perfused rat heart

2009 ◽  
Vol 423 (3) ◽  
pp. 421-428 ◽  
Author(s):  
Bernard Korzeniewski ◽  
Véronique Deschodt-Arsac ◽  
Guillaume Calmettes ◽  
Gilles Gouspillou ◽  
Jean-Michel Franconi ◽  
...  
Keyword(s):  
Heart Rate ◽  
Oxidative Phosphorylation ◽  
Mitochondrial Respiration ◽  
Rat Heart ◽  
Supply And Demand ◽  
Rate Pressure Product ◽  
Perfused Rat Heart ◽  
Physiological Conditions ◽  
Heart Perfusion ◽  
Atp Supply

Mitochondrial respiration/oxidative phosphorylation is the main source of energy, in the form of ATP, in the heart under physiological conditions. Different respiratory substrates were used in various experiments during heart perfusion: glucose, pyruvate, lactate, glucose+pyruvate, glucose+lactate, glucose+insulin etc. Also under physiological conditions, the concentration of respiratory substrates/hormones in blood can vary significantly. In the present study, we tested the effect of pyruvate, lactate and insulin (all in the presence of glucose) and glucose (in the presence of pyruvate) on the ATP-producing and -consuming blocks in perfused rat heart, in a system where HR (heart rate) was allowed to vary (no pacing). Changes in RPP (rate-pressure product) and PCr (phosphocreatine) concentration were measured. PAA (Proportional Activation Approach) was used to visualize and quantitatively analyse the data. It was demonstrated that addition of glucose (in the presence of pyruvate) exerted essentially no effect on the system. Insulin (in the presence of glucose) activated only the ATP producer. The most interesting finding is that, in our system, pyruvate and lactate (added in the presence or instead of glucose) activated ATP producer, but significantly inhibited ATP consumer (their effect was quantitatively identical).

A single intake of capsiate improves mechanical performance and bioenergetics efficiency in contracting mouse skeletal muscle

2014 ◽  
Vol 306 (10) ◽  
pp. E1110-E1119 ◽  
Author(s):  
Yashiro Kazuya ◽  
Anne Tonson ◽  
Emilie Pecchi ◽  
Christiane Dalmasso ◽  
Christophe Vilmen ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Oxidative Phosphorylation ◽  
Mitochondrial Respiration ◽  
Mechanical Performance ◽  
Uncoupling Protein ◽  
Muscle Performance ◽  
Whole Body ◽  
Resonance Spectroscopy ◽  
Twitch Force

Capsiate is known to increase whole body oxygen consumption possibly via the activation of uncoupling processes, but its effect at the skeletal muscle level remains poorly documented and conflicting. To clarify this issue, gastrocnemius muscle function and energetics were investigated in mice 2 h after a single intake of either vehicle (control) or purified capsiate (at 10 or 100 mg/kg body wt) through a multidisciplinary approach combining in vivo and in vitro measurements. Mechanical performance and energy pathway fluxes were assessed strictly noninvasively during a standardized electrostimulation-induced exercise, using an original device implementing 31-phosphorus magnetic resonance spectroscopy, and mitochondrial respiration was evaluated in isolated saponin-permeabilized fibers. Compared with control, both capsiate doses produced quantitatively similar effects at the energy metabolism level, including an about twofold decrease of the mitochondrial respiration sensitivity for ADP. Interestingly, they did not alter either oxidative phosphorylation or uncoupling protein 3 gene expression at rest. During 6 min of maximal repeated isometric contractions, both doses reduced the amount of ATP produced from glycolysis and oxidative phosphorylation but increased the relative contribution of oxidative phosphorylation to total energy turnover (+28 and +21% in the 10- and 100-mg groups, respectively). ATP cost of twitch force generation was further reduced in the 10- (−35%) and 100-mg (−45%) groups. Besides, the highest capsiate dose also increased the twitch force-generating capacity. These data present capsiate as a helpful candidate to enhance both muscle performance and oxidative phosphorylation during exercise, which could constitute a nutritional approach for improving health and preventing obesity and associated metabolic disorders.

scholarly journals The Relationship Between Dive and Pre-Dive Heart Rates in Restrained and Free Dives by Diving Ducks

1987 ◽  
Vol 127 (1) ◽  
pp. 333-348 ◽  
Author(s):  
R. A. FURILLA ◽  
DAVID R. JONES
Keyword(s):  
Heart Rate ◽  
Marked Effect ◽  
Sympathetic Nerves ◽  
Vagal Activity ◽  
Similar Increase ◽  
Lower Heart Rate ◽  
Diving Ducks ◽  
Cardiac Responses ◽  
Cardiac Control ◽  
The Relationship

Dive heart rate was plotted against pre-dive heart rate in forced and voluntary dives and dabbles by restrained and free ducks. The relationship between pre-dive heart rate and the cardiac interval occurring just before or coincident with submersion (first cardiac interval) and the heart rate after 2–5 s submergence (stabilized heart rate) was emphasized. Stabilized heart rate in forced dives by restrained ducks at rest and at the end of a bout of exercise, and heart rate in voluntary dives and dabbles were linearly related on a plot of dive heart rate against the logarithm of predive heart rate. Even the heart rate occurring 2–5 s after ducks were ‘trapped’ under water, compared with the rate immediately before ‘trapping’, fitted on this line. The line was described by the equation y = - 451 + 2461ogx where y is dive (or trapped) and × is pre-dive (or pre-trap) heart rate (r2 = 0.98). The relationship was unaltered by β-blockade with propranolol. Furthermore, nasal blockade with Xylocaine, O2 breathing before submersion, and arterial baroreceptor denervation had no marked effect on the relationship in voluntary and trapped dives. Implantation of stimulating electrodes bilaterally on the cut distal ends of vagal and cardiac sympathetic nerves suggested that in all these dives there is a similar increase in the level of efferent vagal activity during submersion. However, the first cardiac interval in voluntary dives represents a much lower heart rate and therefore higher level of vagal activity. The present data suggest that there is considerable psychogenic modulation of cardiac responses in voluntary diving and only in forced dives, by restrained animals, is cardiac control largely reflexogenic.

scholarly journals Effects of a vibrational proprioceptive stimulation on recovery phase after maximal incremental cycle test

2020 ◽  
Vol 30 (4) ◽  
Author(s):  
Francesco Coscia ◽  
Paola V. Gigliotti ◽  
Saadsaoud Foued ◽  
Alexander Piratinskij ◽  
Tiziana Pietrangelo ◽  
...  
Keyword(s):  
Heart Rate ◽  
Oxygen Saturation ◽  
Recovery Period ◽  
Lactate Concentration ◽  
Recovery Phase ◽  
Exercise Tests ◽  
Peripheral Oxygen Saturation ◽  
Cardiorespiratory Function ◽  
Low Intensity Exercise ◽  
Post Exercise Recovery

Global Proprioceptive Resonance (GPR) is a recently developed approach conceived to solicit the various cutaneous mechanoreceptors, through application of mechanical multifocal vibration at low amplitude and at definite body sites, limiting the stimulation of the profound structures. This interventional study evaluated the effects of GPR on cardiorespiratory function during the post-exertional recovery period. A group of volunteers involved in Triathlon (a multisport discipline consisting of sequential swim, cycle, and run disciplines higly demanding in terms of metabolic engagment), underwent two maximal incremental exercise tests until exhaustion followed alternatively to (a) a 13 minutes section of GPR or (b) a standard low intensity exercise acute trend of the same duration. These effects of these two approaches were compared in terms of recovery of: heart rate (HR), respiratory rate (RR), peripheral oxygen saturation (SpO2) and venous lactate concentration (Lac). The physiological parameters (HR, RR, SpO2 and Lac) recorded in the pre-exertion session showed similar values between the 40 volunteers while several differences were recorded in the post-exertion phase. After 6 min of GPR recovery it was recorded a drop in RR below baseline (19.4±4.15 min-1 vs. 12.2± 0.4 min-1; p<0.001) coupled with an increase in peripheral oxygen saturation above the baseline (GPR: 99.0%±0.16% vs. 96.6%±0.77%, p<0.001). Moreover, the most striking result was the drop in lactate concentration measured after 13 min of GPR recovery: 84.5±3.5% in GPR vs 2.9±7.6% reduction in standard recovery (p<0.001). Notably no differences were recorded recovery of heart rate. GPR has promising effects on post-exercise recovery on RR, SpO2 and lactate level on young athletes.

scholarly journals Effects of a vibrational proprioceptive stimulation on recovery phase after maximal incremental cycle test

2019 ◽  
Vol 29 (3) ◽  
Author(s):  
Francesco Coscia ◽  
Paola V. Gigliotti ◽  
Alexander Piratinskij ◽  
Tiziana Pietrangelo ◽  
Vittore Verratti ◽  
...  
Keyword(s):  
Heart Rate ◽  
Oxygen Saturation ◽  
Recovery Period ◽  
Lactate Concentration ◽  
Recovery Phase ◽  
Exercise Tests ◽  
Peripheral Oxygen Saturation ◽  
Cardiorespiratory Function ◽  
Low Intensity Exercise ◽  
Post Exercise Recovery

Global Proprioceptive Resonance (GPR) is a recently developed approach conceived to solicit the various cutaneous mechanoreceptors, through application of mechanical multifocal vibration at low amplitude and at definite body sites, limiting the stimulation of the profound structures. This interventional study evaluated the effects of GPR on cardiorespiratory function during the post-exertional recovery period. A group of volunteers involved in Triathlon (a multisport discipline consisting of sequential swim, cycle, and run disciplines higly demanding in terms of metabolic engagment), underwent two maximal incremental exercise tests until exhaustion followed alternatively to (a) a 13 minutes section of GPR or (b) a standard low intensity exercise acute trend of the same duration. These effects of these two approaches were compared in terms of recovery of: heart rate (HR), respiratory rate (RR), peripheral oxygen saturation (SpO2) and venous lactate concentration (Lac). The physiological parameters (HR, RR, SpO2 and Lac) recorded in the pre-exertion session showed similar values between the 40 volunteers while several differences were recorded in the post-exertion phase. After 6 min of GPR recovery it was recorded a drop in RR below baseline (19.4±4.15 min-1 vs. 12.2± 0.4 min-1; p<0.001) coupled with an increase in peripheral oxygen saturation above the baseline (GPR: 99.0%±0.16% vs. 96.6%±0.77%, p<0.001). Moreover, the most striking result was the drop in lactate concentration measured after 13 min of GPR recovery: 84.5±3.5% in GPR vs 2.9±7.6% reduction in standard recovery (p<0.001). Notably no differences were recorded recovery of heart rate. GPR has promising effects on post-exercise recovery on RR, SpO2 and lactate level on young athletes.

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