Alterations in ventilation and gas exchange during exercise-induced carbohydrate depletion

1979 ◽  
Vol 57 (6) ◽  
pp. 615-618 ◽  
Author(s):  
H. Green ◽  
M. Houston ◽  
J. Thomson ◽  
P. Reid
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Consumption ◽  
Gas Exchange ◽  
Respiratory Exchange Ratio ◽  
Treadmill Exercise ◽  
Carbon Dioxide Production ◽  
Progressive Reduction ◽  
Energy Substrate ◽  
Carbohydrate Depletion ◽  
Exercise Induced

The relationships between ventilation [Formula: see text], oxygen consumption [Formula: see text], and carbon dioxide production [Formula: see text] during work were studied in four trained males during exercise-induced carbohydrate depletion. Repeated bouts of heavy treadmill exercise (6 min at 95% [Formula: see text]max) were performed once per hour for 24 h in order to promote a shift in energy substrate from carbohydrate to fat. Measurements of [Formula: see text] and [Formula: see text] recorded during each minute indicated that [Formula: see text] was unaffected by the number of runs, whereas [Formula: see text] showed a progressive reduction which amounted to 24% during the final run. A corresponding decline of 19% was observed in the respiratory exchange ratio. No significant change in [Formula: see text] occurred between any of the runs. It is concluded that during heavy, repeated, muscular exercise, reductions in [Formula: see text], strongly suggestive of an increased fat oxidation, are not accompanied by a corresponding change in ventilation.

Blood fuel metabolites in asthma during and after progressive submaximal exercise

1987 ◽  
Vol 73 (1) ◽  
pp. 81-86 ◽  
Author(s):  
G. E. Packe ◽  
J. Wiggins ◽  
B. M. Singh ◽  
M. Nattrass ◽  
A. D. Wright ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Consumption ◽  
Oxygen Saturation ◽  
Ketone Body ◽  
Respiratory Exchange Ratio ◽  
Carbon Dioxide Production ◽  
Hydrogen Ion ◽  
Control Subjects ◽  
Progressive Exercise ◽  
And Control

1. Ten male stable asthmatic subjects and 10 matched control subjects performed a progressive exercise test on a treadmill to 85% of their predicted maximum heart rate. 2. Blood lactate, pyruvate, hydrogen ion, glucose, alanine, glycerol and total ketone body concentrations were measured at frequent intervals during and up to 60 min after exercise. Carbon dioxide production, oxygen consumption, ventilation, respiratory exchange ratio and oxygen saturation were also measured during and up to 10 min after exercise. 3. There were no significant differences between the asthmatic and control subjects in levels of carbon dioxide production, oxygen consumption and ventilation. The respiratory exchange ratio was greater in the asthmatic subjects during recovery from exercise (P < 0.05). No changes in oxygen saturation were observed during exercise in either group. 4. In both asthmatic and control subjects, lactate, pyruvate, hydrogen ion, alanine and glycerol concentrations showed an increase from baseline levels, reaching maximum levels up to 10 min after exercise and returning to baseline within 1 h after exercise. Total ketone body concentrations decreased during exercise. 5. There were no significant differences between the asthmatic and control subjects in the concentration of any metabolite over the study period. 6. These data indicate that fuel metabolism during and after short-term progressive exercise is similar in stable asthmatic and normal subjects.

Quantitative methanol-burning lung model for validating gas-exchange measurements over wide ranges of F I O 2

1998 ◽  
Vol 84 (6) ◽  
pp. 2177-2182 ◽  
Author(s):  
Saul Miodownik ◽  
Jose Melendez ◽  
Vittoria Arslan Carlon ◽  
Brian Burda
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Consumption ◽  
Gas Exchange ◽  
Combustion Rate ◽  
Respiratory Quotient ◽  
Infusion Rate ◽  
Carbon Dioxide Production ◽  
Lung Model ◽  
Burner Device ◽  
Extended Range

The methanol-burning lung model has been used as a technique for generating a predictable ratio of carbon dioxide production (V˙co 2) to oxygen consumption (V˙o 2) or respiratory quotient (RQ). Although an accurate RQ can be generated, quantitatively predictable and adjustableV˙o 2 andV˙co 2 cannot be generated. We describe a new burner device in which the combustion rate of methanol is always equal to the infusion rate of fuel over an extended range of O2 concentrations. This permits the assembly of a methanol-burning lung model that is usable with O2 concentrations up to 100% and provides continuously adjustable and quantitativeV˙o 2 (69–1,525 ml/min) and V˙co 2 (46–1,016 ml/min) at a RQ of 0.667.

scholarly journals The Relative Efficiency of Gaseous Exchange Across the Lungs and Gills of an African Lungfish Protopterus Aethiopicus

1970 ◽  
Vol 52 (1) ◽  
pp. 1-15
Author(s):  
B. R. McMAHON
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Consumption ◽  
Gas Exchange ◽  
Direct Measurement ◽  
Relative Efficiency ◽  
Lung Ventilation ◽  
Carbon Dioxide Production ◽  
Gaseous Exchange ◽  
Terrestrial Vertebrates ◽  
African Lungfish

1. The efficiency of gas exchange over the lung and gill surfaces of Protopterus has been investigated. 2. Animals confined in water or in air showed an increased respiratory frequency in the remaining medium, indicating that both routes were important in the total gas exchange. 3. Direct measurement of the oxygen and carbon dioxide tensions of pulmonary air and inspired and expired branchial water showed gas exchange ratios (R) of 0.2 for the lung and 5.0 for the gills approximately, demonstrating that more oxygen was consumed via the lungs and more carbon dioxide excreted via the gills. 4. Oxygen consumption and carbon dioxide production were measured directly in a respirometer in which respiratory air and water streams could be kept separate except during lung ventilation. At least 90% of the animals' oxygen consumption occurred in the lung, while 60 % of the carbon dioxide excreted passed via the aquatic route. 5. The results are discussed with reference to the animals' adaptation to its environment and with reference to the evolution of the terrestrial vertebrates.

scholarly journals Prolonged treadmill running in normobaric hypoxia causes gastrointestinal barrier permeability and elevates circulating levels of pro- and anti-inflammatory cytokines

2020 ◽  
Vol 45 (4) ◽  
pp. 376-386 ◽  
Author(s):  
Garrett W. Hill ◽  
Trevor L. Gillum ◽  
Ben J. Lee ◽  
Phebe A. Romano ◽  
Zach J. Schall ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Consumption ◽  
Treadmill Exercise ◽  
Minute Ventilation ◽  
Carbon Dioxide Production ◽  
Normobaric Hypoxia ◽  
Treadmill Running ◽  
Gut Barrier ◽  
Barrier Permeability ◽  
Gastrointestinal Barrier

This study examined the impact of treadmill running in normobaric hypoxia on gastrointestinal barrier permeability and the systemic inflammatory response. Ten recreationally active participants completed two 1-h bouts of matched-workload treadmill exercise (65% normoxic maximal oxygen consumption) in counterbalanced order. One bout was performed in normoxia (NORM: fraction of inspired oxygen (FIO2) = 20.9%) and the other in normobaric hypoxia (HYP: FIO2 = 13.5%). Minute ventilation, respiratory rate (RR), tidal volume (VT), oxygen consumption, carbon dioxide production, respiratory exchange ratio (RER), and heart rate (HR) were measured with a metabolic cart. Peripheral oxygen saturation (SpO2) was measured with pulse oximetry. Absolute tissue saturation (StO2) was measured with near-infrared spectroscopy. Fatty acid-binding protein (I-FABP) and circulating cytokine concentrations (interleukin (IL)-1Ra, IL-6, IL-10) were assayed from plasma samples that were collected pre-exercise, postexercise, 1 h-postexercise, and 4 h-postexercise. Data were analyzed with 2-way (condition × time) repeated-measures ANOVAs. Newman–Keuls post hoc tests were run where appropriate (p < 0.05). As compared with NORM, 1 h of treadmill exercise in HYP caused greater (p < 0.05) changes in minute ventilation (+30%), RR (+16%), VT (+10%), carbon dioxide production (+18%), RER (+16%), HR (+4%), SpO2 (–16%), and StO2 (–10%). Gut barrier permeability and circulating cytokine concentrations were also greater (p < 0.05) following HYP exercise, where I-FABP was shown increased at postexercise (+68%) and IL-1Ra at 1 h-postexercise (+266%). I-FABP and IL-1Ra did not change (p > 0.05) following NORM exercise. IL-6 and IL-10 increased with exercise in both study conditions but were increased more (p < 0.05) following HYP at postexercise (+705% and +127%, respectively) and 1 h-postexercise (+400% and +128%, respectively). Novelty Normobaric hypoxia caused significant desaturation and increased most cardiopulmonary responses by 10%–30%. Significant gut barrier permeability and increased pro- and anti-inflammatory cytokine concentrations could promote an “open window” in the hours following HYP exercise.

scholarly journals The influence of temperature on the metabolic regulation and gas exchange of the Highveld scorpion, Opistophthalmus latimanus ( Koch ) ( Scorpionidae )

2012 ◽  
Vol 31 (1) ◽  
Author(s):  
Willie J. Van Aardt ◽  
Japie Mienie ◽  
J.M. Le Roux
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Consumption ◽  
Gas Exchange ◽  
Oxygen Consumption Rate ◽  
Metabolic Regulation ◽  
Consumption Rate ◽  
Carbon Dioxide Production ◽  
Influence Of Temperature ◽  
Influence Of Temperature On ◽  
Carbon Dioxide Production Rate

Adult scorpions (2.4g – 4.5 kg) were collected near Potchefstroom (26° .55’10” – 27° 10” 5”). Oxygen consumption rate (MO2) and carbon dioxide production rate (MCO2) were measured together with the metabolism of injected radioactive glucose.

Metabolism during normoxia, hyperoxia, and recovery in newborn rats

1992 ◽  
Vol 70 (3) ◽  
pp. 408-411 ◽  
Author(s):  
Peter B. Frappell ◽  
Andrea Dotta ◽  
Jacopo P. Mortola
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Consumption ◽  
Metabolic Rate ◽  
Carbon Dioxide Production ◽  
Oxygen Availability ◽  
Aerobic Metabolism ◽  
Newborn Rats ◽  
Ambient Temperatures ◽  
Positive Effects

Aerobic metabolism (oxygen consumption, [Formula: see text], and carbon dioxide production, [Formula: see text]) has been measured in newborn rats at 2 days of age during normoxia, 30 min of hyperoxia (100% O2) and an additional 30 min of recovery in normoxia at ambient temperatures of 35 °C (thermoneutrality) or 30 °C. In normoxia, at 30 °C [Formula: see text] was higher than at 35 °C. With hyperoxia, [Formula: see text] increased in all cases, but more so at 30 °C (+20%) than at 35 °C (+9%). Upon return to normoxia, metabolism readily returned to the prehyperoxic value. The results support the concept that the normoxic metabolic rate of the newborn can be limited by the availability of oxygen. At temperatures below thermoneutrality the higher metabolic needs aggravate the limitation in oxygen availability, and the positive effects of hyperoxia on [Formula: see text] are therefore more apparent.Key words: neonatal respiration, oxygen consumption, thermoregulation.

GASEOUS METABOLISM IN PREMATURE INFANTS AT 32-34°C AMBIENT TEMPERATURE

PEDIATRICS ◽  
1964 ◽  
Vol 33 (1) ◽  
pp. 75-82
Author(s):  
Forrest H. Adams ◽  
Tetsuro Fujiwara ◽  
Robert Spears ◽  
Joan Hodgman
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Consumption ◽  
Premature Infants ◽  
Rectal Temperature ◽  
Respiratory Quotient ◽  
Carbon Dioxide Production ◽  
Open Circuit ◽  
Co2 Production ◽  
O2 Consumption ◽  
Rate Of Increase

Thirty-four measurements of oxygen consumption, carbon dioxide production, respiratory quotient, and rectal temperature were made on 22 premature infants with ages ranging from 2½ hours to 18 days. The studies were conducted at 32-34°C utilizing an open circuit apparatus and a specially designed climatized chamber. Oxygen consumption and carbon dioxide production were lowest in the first 12 hours and increased thereafter. The rate of increase in O2 consumption was greater than that of CO2 production, with a consequent fall in respiratory quotient during the first 76 hours of life. A reverse relation of O2 consumption and CO2 production was found following the 4th day of life with a consequent rise in respiratory quotient. There was a close correlation between O2 consumption and rectal temperature regardless of age. A respiratory quotient below the value of 0.707 for fat metabolism was observed in 7 premature infants with ages ranging from 24 to 76 hours.

Measurement of ‘Basal’ and Total Metabolism in Hereditarily Obese-Hyperglycemic Mice

1958 ◽  
Vol 193 (3) ◽  
pp. 495-498 ◽  
Author(s):  
Ruth McClintock ◽  
Nathan Lifson
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Consumption ◽  
Energy Expenditure ◽  
Voluntary Movement ◽  
Carbon Dioxide Production ◽  
Open Circuit ◽  
Energy Output ◽  
Obese Mice ◽  
Energy Expenditures ◽  
Isotope Method

Measurements of oxygen consumption and carbon dioxide production were made by the Haldane open circuit method on hereditarily obese mice and littermate controls, and the energy expenditures were estimated. Studies were made on mice for short periods under ‘basal’ conditions, and for periods of approximately a day with the mice fasted and confined, fasted and relatively unconfined, and fed and unconfined. The total energy expenditures of fed and unconfined obese mice were found to be higher than those of nonobese littermate controls by virtue of a) increased ‘basal metabolism’, b) greater energy expenditure associated with feeding, and possibly c) larger energy output for activity despite reduced voluntary movement. The values obtained for total metabolism confirm those previously determined by an isotope method for measuring CO2 output.

Sign in / Sign up

Export Citation Format

Share Document