Glycogen utilization in rat respiratory muscles during intense running

1988 ◽  
Vol 66 (7) ◽  
pp. 917-923 ◽  
Author(s):  
Howard J. Green ◽  
M. E. Ball-Burnett ◽  
M. A. Morrissey ◽  
J. Kile ◽  
G. C. Abraham
Keyword(s):  
Energy Metabolism ◽  
Vastus Lateralis ◽  
Lactate Concentration ◽  
Respiratory Muscles ◽  
Large Degree ◽  
Recruitment Strategy ◽  
Rat Diaphragm ◽  
Intercostal Muscles ◽  
Glycogen Concentration ◽  
Locomotor Muscles

Glycogen concentration in the adult rat diaphragm and intercostal muscles has been examined following heavy treadmill exercise to determine the recruitment strategy and the significance of glycogen as a substrate to satisfy the elevated energy requirements accompanying hyperpnea. Short-term continuous running at 60 m/min and a 12° grade resulted in a reduction (p < 0.05) in the concentration of glycogen (39%) in the costal region of the rat diaphragm. Similarly, glycogen concentration was significantly reduced (p < 0.05) with this exercise protocol in all respiratory muscles studied, with the exception of the sternal region of the diaphragm. With the less intense running protocols, glycogen degradation continued to be pronounced (p < 0.05) in the majority of the respiratory muscles sampled. The significance of muscle glycogen as a substrate for energy metabolism in the respiratory muscles was not affected by the procedure used to prepare the animal for tissue sampling (Somnitol, diethyl ether, decapitation). Examination of selected locomotor muscles revealed extensive glycogen loss in muscles composed of essentially slow oxidative fibres (soleus), fast oxidative glycolytic fibres (vastus lateralis red), and fast glycolytic fibres (vastus lateralis white). It is concluded that during heavy exercise in the rat, recruitment of motor units occurs in all regions of the diaphragm and in the intercostal muscles. At least for the costal region of the diaphragm and as evidenced by the modest (two- to four-fold) but significant (p < 0.05) increases in lactate concentration, the increased ATP requirements in these muscles are met to a large degree by increases in aerobic metabolism. It is concluded that endogenous glycogen is an important substrate for energy metabolism during intense running in both the respiratory and locomotor muscles regardless of fibre composition.

scholarly journals Sex-Differences in the Oxygenation Levels of Intercostal and Vastus Lateralis Muscles During Incremental Exercise

2021 ◽  
Vol 12 ◽  
Author(s):  
Maximiliano Espinosa-Ramírez ◽  
Eduardo Moya-Gallardo ◽  
Felipe Araya-Román ◽  
Santiago Riquelme-Sánchez ◽  
Guido Rodriguez-García ◽  
...  
Keyword(s):  
Sex Differences ◽  
Physical Exercise ◽  
Oxygen Saturation ◽  
Vastus Lateralis ◽  
Respiratory Muscles ◽  
Lung Ventilation ◽  
Cycle Ergometer ◽  
Incremental Test ◽  
Physically Active ◽  
Locomotor Muscles

This study aimed to examine sex differences in oxygen saturation in respiratory (SmO2-m.intercostales) and locomotor muscles (SmO2-m.vastus lateralis) while performing physical exercise. Twenty-five (12 women) healthy and physically active participants were evaluated during an incremental test with a cycle ergometer, while ventilatory variables [lung ventilation (V.E), tidal volume (Vt), and respiratory rate (RR)] were acquired through the breath-by-breath method. SmO2 was acquired using the MOXY® devices on the m.intercostales and m.vastus lateralis. A two-way ANOVA (sex × time) indicated that women showed a greater significant decrease of SmO2-m.intercostales, and men showed a greater significant decrease of SmO2-m.vastus lateralis. Additionally, women reached a higher level of ΔSmO2-m.intercostales normalized to V.E (L⋅min–1) (p &lt; 0.001), whereas men had a higher level of ΔSmO2-m.vastus lateralis normalized to peak workload-to-weight (watts⋅kg–1, PtW) (p = 0.049), as confirmed by Student’s t-test. During an incremental physical exercise, women experienced a greater cost of breathing, reflected by greater deoxygenation of the respiratory muscles, whereas men had a higher peripheral load, indicated by greater deoxygenation of the locomotor muscles.

scholarly journals Ultrasonographic assessment of parasternal intercostal muscles during mechanical ventilation

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Paolo Formenti ◽  
Michele Umbrello ◽  
Martin Dres ◽  
Davide Chiumello
Keyword(s):  
Mechanical Ventilation ◽  
Ultrasound Imaging ◽  
Muscle Weakness ◽  
Respiratory Muscle ◽  
Muscle Activation ◽  
Invasive Mechanical Ventilation ◽  
Respiratory Muscles ◽  
Course Of Illness ◽  
Intercostal Muscles ◽  
Predictive Parameters

Abstract Although mechanical ventilation is a lifesaving treatment, abundant evidence indicates that its prolonged use (1 week or more) promotes respiratory muscle weakness due to both contractile dysfunction and atrophy. Along with the diaphragm, the intercostal muscles are one of the most important groups of respiratory muscles. In recent years, muscular ultrasound has become a useful bedside tool for the clinician to identify patients with respiratory muscle dysfunction related to critical illness and/or invasive mechanical ventilation. Images obtained over the course of illness can document changes in muscle dimension and can be used to estimate changes in function. Recent evidence suggests the clinical usefulness of ultrasound imaging in the assessment of intercostal muscle function. In this narrative review, we summarize the current literature on ultrasound imaging of the parasternal intercostal muscles as used to assess the extent of muscle activation and muscle weakness and its potential impact during discontinuation of mechanical ventilation. In addition, we proposed a practical flowchart based on recent evidence and experience of our group that can be applied during the weaning phase. This approach integrates multiple predictive parameters of weaning success with respiratory muscle ultrasound.

Muscle glycogen availability and temperature regulation in humans

1989 ◽  
Vol 66 (1) ◽  
pp. 72-78 ◽  
Author(s):  
L. Martineau ◽  
I. Jacobs
Keyword(s):  
Skeletal Muscle ◽  
Muscle Glycogen ◽  
Temperature Regulation ◽  
Vastus Lateralis ◽  
Water Immersion ◽  
Vastus Lateralis Muscle ◽  
Glycogen Concentration ◽  
Exercise Regimen ◽  
Before And After ◽  
Muscle Groups

The effects of intramuscular glycogen availability on human temperature regulation were studied in eight seminude subjects immersed in 18 degrees C water for 90 min or until rectal temperature (Tre) decreased to 35.5 degrees C. Each subject was immersed three times over a 3-wk period. Each immersion followed 2.5 days of a specific dietary and/or exercise regimen designed to elicit low (L), normal (N), or high (H) glycogen levels in large skeletal muscle groups. Muscle glycogen concentration was determined in biopsies taken from the vastus lateralis muscle before and after each immersion. Intramuscular glycogen concentration before the immersion was significantly different among the L, N, and H trials (P less than 0.01), averaging 247 +/- 15, 406 +/- 23, and 548 +/- 42 (SE) mmol glucose units.kg dry muscle-1, respectively. The calculated metabolic heat production during the first 30 min of immersion was significantly lower during L compared with N or H (P less than 0.05). The rate at which Tre decreased was more rapid during the L immersion than either N or H (P less than 0.05), and the time during the immersion at which Tre first began to decrease also appeared sooner during L than N or H. The results suggest that low skeletal muscle glycogen levels are associated with more rapid body cooling during water immersion in humans. Higher than normal muscle glycogen levels, however, do not increase cold tolerance.

scholarly journals Noninvasive evaluation of respiratory muscles in pre-clinical model of Duchenne Muscular Dystrophy

2016 ◽  
Vol 36 (4) ◽  
pp. 290-296
Author(s):  
Daniela M. Oliveira ◽  
Stefano C. Hagen ◽  
Amilton C. Santos ◽  
Maria A. Miglino ◽  
Antônio C. Assis Neto
Keyword(s):  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Respiratory Muscles ◽  
Experimental Models ◽  
Noninvasive Evaluation ◽  
Control Group ◽  
Clinical Model ◽  
Intercostal Muscles ◽  
Invasive Method ◽  
Clinical Conditions

Abstract Since respiratory insufficiency is the main cause of death in patients affected by Duchenne Muscular Dystrophy (DMD), the present study aims at establishing a new non-invasive method to evaluate the clinical parameters of respiratory conditions of experimental models affected by DMD. With this purpose in mind, we evaluated the cardiorespiratory clinical conditions, the changes in the intercostal muscles, the diaphragmatic mobility, and the respiratory cycles in Golden Retriever Muscular Dystrophy (GRMD) employing ultrasonography (US). A control group consisting of dogs of the same race, but not affected by muscular dystrophy, were used in this study. The results showed that inspiration, expiration and plateau movements (diaphragm mobility) were lower in the affected group. Plateau phase in the affected group was practically non-existent and showed that the diaphragm remained in constant motion. Respiratory rate reached 15.5 per minute for affected group and 26.93 per minute for the control group. Expiration and inspiration movements of intercostal muscles reached 8.99mm and 8.79mm, respectively, for control group and 7.42mm and 7.40mm, respectively, for affected group. Methodology used in the present analysis proved to be viable for the follow-up and evaluation of the respiratory model in GRMD and may be adapted to other muscular dystrophy experimental models.

Electrical and mechanical activity of respiratory muscles during hypercapnia

1986 ◽  
Vol 61 (2) ◽  
pp. 719-727 ◽  
Author(s):  
E. van Lunteren ◽  
N. S. Cherniack
Keyword(s):  
Moving Average ◽  
Respiratory Muscles ◽  
Mechanical Activity ◽  
Intercostal Muscles ◽  
Co2 Rebreathing ◽  
Single Breath ◽  
Linear Relationships ◽  
Muscle Shortening ◽  
Close Relationship ◽  
Spontaneously Breathing

In nine anesthetized supine spontaneously breathing dogs, we compared moving average electromyograms (EMGs) of the costal diaphragm and the third parasternal intercostal muscles with their respective respiratory changes in length (measured by sonomicrometry). During resting O2 breathing the pattern of diaphragm and intercostal muscle inspiratory shortening paralleled the gradually incrementing pattern of their moving average EMGs. Progressive hypercapnia caused progressive increases in the amount and velocity of respiratory muscle inspiratory shortening. For both muscles there were linear relationships during the course of CO2 rebreathing between their peak moving average EMGs and total inspiratory shortening and between tidal volume and total inspiratory shortening. During single-breath airway occlusions, the electrical activity of both the diaphragm and intercostal muscles increased, but there were decreases in their tidal shortening. The extent of muscle shortening during occluded breaths was increased by hypercapnia, so that both muscles shortened more during occluded breaths under hypercapnic conditions (PCO2 up to 90 Torr) than during unoccluded breaths under normocapnic conditions. These results suggest that for the costal diaphragm and parasternal intercostal muscles there is a close relationship between their electrical and mechanical behavior during CO2 rebreathing, this relationship is substantially altered by occluding the airway for a single breath, and thoracic respiratory muscles do not contract quasi-isometrically during occluded breaths.

SR stress in locomotor muscles of patients with chronic obstructive pulmonary disease

2020 ◽  
Author(s):  
Rizwan Qaisar ◽  
Mughal Qayyum ◽  
Tahir Muhammad
Keyword(s):  
Chronic Obstructive Pulmonary Disease ◽  
Skeletal Muscle ◽  
Pulmonary Disease ◽  
Vastus Lateralis ◽  
Therapeutic Interventions ◽  
Chronic Obstructive ◽  
Potential Contribution ◽  
Healthy Controls ◽  
Obstructive Pulmonary Disease ◽  
Locomotor Muscles

Abstract Background The potential contribution of chronic dysregulation of sarcoplasmic reticulum (SR) protein homeostasis (a condition called SR stress) to skeletal muscle loss is poorly understood. We investigated the degree of activation of SR stress in locomotor muscles of patients with chronic obstructive pulmonary disease (COPD), a respiratory disease with systemic manifestations. Methods We analyzed the markers of SR stress and associated pathologies in vastus lateralis muscles of 60-65 years old male healthy controls and patients with mild (COPD stages 1 & 2) and advanced (COPD stages 3 & 4) COPD (N = 6-8 / group). Results Skeletal muscle proteins expressions of GRP94, BiP, CHOP and ATF were significantly elevated in advanced COPD (≈53%, ≈3.6 fold, ≈3.5 fold and ≈3.2 fold, respectively) compared with healthy controls. The expression of downstream markers of SR stress including apoptosis, inflammation and autophagy was increased, while the maximal activity of SR Ca2+ ATPase (SERCA) enzyme was significantly reduced in advanced COPD (≈41%) than healthy controls. Single muscle fiber diameter and cytoplasmic domain per myonucleus were significantly smaller (≈14% and 13%, respectively) in patients with advanced COPD than healthy controls. These changes in SR dysfunction were accompanied by substantially elevated levels of global oxidative stress including lipid peroxidation and mitochondrial ROS production. Conclusion Taken together, our data suggests that the muscle weakness in advanced COPD is in part driven by elevated SR stress and its pathological consequences. The data provided can lead to potential therapeutic interventions of SR dysfunction for muscle detriment in COPD.

Action potentials of accessory respiratory muscles in dogs

1960 ◽  
Vol 199 (3) ◽  
pp. 569-572 ◽  
Author(s):  
T. Ogawa ◽  
N. C. Jefferson ◽  
J. E. Toman ◽  
T. Chiles ◽  
A. Zambetoglou ◽  
...  
Keyword(s):  
Action Potentials ◽  
Respiratory Muscles ◽  
Transversus Abdominis ◽  
Intercostal Muscles ◽  
Intrinsic Muscle ◽  
Internal Oblique ◽  
Accessory Respiratory Muscles

Among 30 so-called accessory respiratory and other muscles tested, the presence of rhythmic respiratory impulses was found in 12. Both expiratory and inspiratory impulses were detected in certain muscles, in others only in- or expiratory ones. The muscles with most frequent inspiratory impulses were the intercartilaginous intercostal muscles, the intrinsic muscle of the larynx and the nostril; those with expiratory impulses were abdominis, external and internal oblique, transversus abdominis, scalenus anterior, and lower interosseous intercostal muscles.

scholarly journals A Novel Method for Classification of Running Fatigue Using Change-Point Segmentation

Sensors ◽  
2019 ◽  
Vol 19 (21) ◽  
pp. 4729 ◽  
Author(s):  
Taha Khan ◽  
Lina E. Lundgren ◽  
Eric Järpe ◽  
M. Charlotte Olsson ◽  
Pelle Viberg
Keyword(s):  
Random Forest ◽  
Blood Lactate ◽  
Change Point ◽  
Vastus Lateralis ◽  
Lactate Concentration ◽  
Treadmill Running ◽  
Vastus Lateralis Muscle ◽  
Semg Signal ◽  
Novel Method

Blood lactate accumulation is a crucial fatigue indicator during sports training. Previous studies have predicted cycling fatigue using surface-electromyography (sEMG) to non-invasively estimate lactate concentration in blood. This study used sEMG to predict muscle fatigue while running and proposes a novel method for the automatic classification of running fatigue based on sEMG. Data were acquired from 12 runners during an incremental treadmill running-test using sEMG sensors placed on the vastus-lateralis, vastus-medialis, biceps-femoris, semitendinosus, and gastrocnemius muscles of the right and left legs. Blood lactate samples of each runner were collected every two minutes during the test. A change-point segmentation algorithm labeled each sample with a class of fatigue level as (1) aerobic, (2) anaerobic, or (3) recovery. Three separate random forest models were trained to classify fatigue using 36 frequency, 51 time-domain, and 36 time-event sEMG features. The models were optimized using a forward sequential feature elimination algorithm. Results showed that the random forest trained using distributive power frequency of the sEMG signal of the vastus-lateralis muscle alone could classify fatigue with high accuracy. Importantly for this feature, group-mean ranks were significantly different (p < 0.01) between fatigue classes. Findings support using this model for monitoring fatigue levels during running.

Extra- and intracellular water spaces in muscles of man at rest and with dynamic exercise

1982 ◽  
Vol 243 (3) ◽  
pp. R271-R280 ◽  
Author(s):  
G. Sjogaard ◽  
B. Saltin
Keyword(s):  
Water Content ◽  
Vastus Lateralis ◽  
Lactate Concentration ◽  
Total Water Content ◽  
Total Water ◽  
Triceps Brachii ◽  
Bicycle Exercise ◽  
Tissue Samples ◽  
Intracellular Space ◽  
Extracellular Lactate

A method was established to analyze the extracellular water space (H2Oe) in small muscle tissue samples as [3H]inulin distribution space. After initial experiments on rats, the method was applied on 13 men and 6 women. Muscles with different fiber compositions (soleus, S; vastus lateralis, (VL; gastrocnemius, G; triceps brachii, TB) were studied at rest. The total water content was the same for all muscles, 320 (313-330) ml/100 g dry wt. However, differences were demonstrated for H2Oe, with 26-34 ml/100 g dry wt in VL and 38-54 ml/100 g dry wt in S, (P less than 0.05); the values for G and TB were in between those for VL and S. The differences in H2Oe were not related to the fiber composition of the muscles. During 3 x 3 min of intense bicycle exercise demanding about 120% VO2 max (6 men), total water content increased in VL from 313 to 359 ml/100 g dry wt and H2Oe increased from 34 to 60 ml/100 g dry wt (P less than 0.05), In TB, which is relatively inactive during bicycle exercise, no such changes occurred. The calculated intracellular lactate concentration increased in VL from 5.7 to 30.6 mmol/l H2Oi. The extracellular lactate concentration amounted to 13.6 mmol/l H2Oe at the end of exercise. The concentration gradient for lactate of 2 from intra- to extracellular space favored a flux of water to the intracellular space. The relative large increase in H2Oe may then be caused by a hydrostatic rather than an osmotic factor.U

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