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 ◽  
...  

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.

1979 ◽  
Vol 57 (6) ◽  
pp. 615-618 ◽  
Author(s):  
H. Green ◽  
M. Houston ◽  
J. Thomson ◽  
P. Reid

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.


1992 ◽  
Vol 70 (3) ◽  
pp. 408-411 ◽  
Author(s):  
Peter B. Frappell ◽  
Andrea Dotta ◽  
Jacopo P. Mortola

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.


PEDIATRICS ◽  
1964 ◽  
Vol 33 (1) ◽  
pp. 75-82
Author(s):  
Forrest H. Adams ◽  
Tetsuro Fujiwara ◽  
Robert Spears ◽  
Joan Hodgman

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.


1958 ◽  
Vol 193 (3) ◽  
pp. 495-498 ◽  
Author(s):  
Ruth McClintock ◽  
Nathan Lifson

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.


2018 ◽  
pp. 94-100
Author(s):  
John R. B. Lighton

This chapter demystifies respirometry equations, showing how they can be derived using a simple mental trick: focusing the analysis on the principal gas that is neither consumed nor produced by animals. The effect of dilution of oxygen by carbon dioxide, the enrichment of carbon dioxide by the consumption of oxygen, and the effects of water vapor on the concentrations of both gases are described and quantified. A system of eight equations is derived that allow oxygen consumption and carbon dioxide production to be calculated in practically any feasible flow-through respirometry system.


1953 ◽  
Vol 4 (3) ◽  
pp. 334 ◽  
Author(s):  
RJ Swaby ◽  
BI Passey

A simple macrorespirometer is described which is capable of providing a continuous record of oxygen consumption and an intermittent record of carbon-dioxide production by pure or mixed cultures of microorganisms in soil and compost.


1996 ◽  
Vol 81 (4) ◽  
pp. 1754-1761 ◽  
Author(s):  
Jon K. Moon ◽  
Nancy F. Butte

Moon, Jon K., and Nancy F. Butte. Combined heart rate and activity improve estimates of oxygen consumption and carbon dioxide production rates. J. Appl. Physiol.81(4): 1754–1761, 1996.—Oxygen consumption (V˙o 2) and carbon dioxide production (V˙co 2) rates were measured by electronically recording heart rate (HR) and physical activity (PA). Mean daily V˙o 2 andV˙co 2 measurements by HR and PA were validated in adults ( n = 10 women and 10 men) with room calorimeters. Thirteen linear and nonlinear functions of HR alone and HR combined with PA were tested as models of 24-h V˙o 2 andV˙co 2. Mean sleepV˙o 2 andV˙co 2 were similar to basal metabolic rates and were accurately estimated from HR alone [respective mean errors were −0.2 ± 0.8 (SD) and −0.4 ± 0.6%]. The range of prediction errors for 24-h V˙o 2 andV˙co 2 was smallest for a model that used PA to assign HR for each minute to separate active and inactive curves (V˙o 2, −3.3 ± 3.5%; V˙co 2, −4.6 ± 3%). There were no significant correlations betweenV˙o 2 orV˙co 2 errors and subject age, weight, fat mass, ratio of daily to basal energy expenditure rate, or fitness. V˙o 2,V˙co 2, and energy expenditure recorded for 3 free-living days were 5.6 ± 0.9 ml ⋅ min−1 ⋅ kg−1, 4.7 ± 0.8 ml ⋅ min−1 ⋅ kg−1, and 7.8 ± 1.6 kJ/min, respectively. Combined HR and PA measured 24-h V˙o 2 andV˙co 2 with a precision similar to alternative methods.


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