Oxygen Consumption, Carbon Dioxide Excretion and Respiratory Quotient of Larval Lampreys (Mordacia mordax) in Air

Author(s):  
I.C Potter ◽  
D.J Macey ◽  
A.R Roberts ◽  
P.C Withers
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.


1965 ◽  
Vol 20 (2) ◽  
pp. 308-310 ◽  
Author(s):  
Hrishikesh Jana

The energy metabolism of 14 healthy males was studied before and during a hypnotic trance in the basal state. Metabolic rates during the basal waking, the basal hypnotic trance and the basal sleep were also determined in three subjects for 3 consecutive days, respectively. It was observed that a hypnotic trance does not significantly influence the metabolic rates in a basal condition while natural sleep lowers the basal metabolic rates by 8.73%. hypnosis; oxygen consumption; carbon dioxide; elimination; respiratory quotient Submitted on April 7, 1964


1969 ◽  
Vol 23 (2) ◽  
pp. 407-413 ◽  
Author(s):  
L. E. Mount

1. Rates of oxygen consumption and carbon dioxide production were measured in pigs from birth to 3 days of age in an open-circuit system.2. The mean respiratory quotient (RQ) during the first 6 h following birth was 0.95 in fasted pigs and 0.91 in pigs which were allowed to feed.3. The RQ fell during the remainder of the first postnatal day to mean values close to 0.85, whether the pigs were allowed to feed from birth or were fasted.4. From 1 to 3 days of age the RQ had a mean value of 0.79.5. There was little difference in the RQ of pigs exposed to environmental temperatures of either 32 or 16°.6. It is concluded that the baby pig is not exclusively dependent on carbohydrate for its energy metabolism.


2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Patrick Lauscher ◽  
Sabine Lauscher ◽  
Harry Kertscho ◽  
Oliver Habler ◽  
Jens Meier

Aim. Ventilation with pure oxygen (hyperoxic ventilation: HV) is thought to decrease whole body oxygen consumption (VO2). However, the validity and impact of this phenomenon remain ambiguous; until now, under hyperoxic conditions,VO2has only been determined by the reverse Fick principle, a method with inherent methodological problems. The goal of this study was to determine changes ofVO2, carbon dioxide production (VCO2), and the respiratory quotient (RQ) during normoxic and hyperoxic ventilation, using a metabolic monitor.Methods. After providing signed informed consent and institutional acceptance, 14 healthy volunteers were asked to sequentially breathe room air, pure oxygen, and room air again.VO2, VCO2, RQ, and energy expenditure (EE) were determined by indirect calorimetry using a modified metabolic monitor during HV.Results. HV reducedVO2from 3.4 (3.0/4.0) mL/kg/min to 2.8 (2.5/3.6) mL/kg/min (P<0.05), whereas VCO2remained constant (3.0 [2.6/3.6] mL/kg/min versus 3.0 [2.6/3.5] mL/kg/min, n.s.). After onset of HV, RQ increased from 0.9 (0.8/0.9) to 1.1 (1.0/1.1). Most changes during HV were immediately reversed during subsequent normoxic ventilation.Conclusion. HV not only reducesVO2, but also increases the respiratory quotient. This might be interpreted as an indicator of the substantial metabolic changes induced by HV. However, the impact of this phenomenon requires further study.


1998 ◽  
Vol 84 (6) ◽  
pp. 2177-2182 ◽  
Author(s):  
Saul Miodownik ◽  
Jose Melendez ◽  
Vittoria Arslan Carlon ◽  
Brian Burda

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.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Koichiro Shinozaki ◽  
Yu Okuma ◽  
Kota Saeki ◽  
Santiago J. Miyara ◽  
Tomoaki Aoki ◽  
...  

AbstractUsing a new method for measuring the molecular ratio (R) of inhalation to exhalation, we investigated the effect of high fraction of inspired oxygen (FIO2) on oxygen consumption (VO2), carbon dioxide generation (VCO2), and respiratory quotient (RQ) in mechanically ventilated rats. Twelve rats were equally assigned into two groups by anesthetics: intravenous midazolam/fentanyl vs. inhaled isoflurane. R, VO2, VCO2, and RQ were measured at FIO2 0.3 or 1.0. R error was ± 0.003. R was 1.0099 ± 0.0023 with isoflurane and 1.0074 ± 0.0018 with midazolam/fentanyl. R was 1.0081 ± 0.0017 at an FIO2 of 0.3 and 1.0092 ± 0.0029 at an FIO2 of 1.0. There were no differences in VCO2 among the groups. VO2 increased at FIO2 1.0, which was more notable when midazolam/fentanyl was used (isoflurane-FIO2 0.3: 15.4 ± 1.1; isoflurane-FIO2 1.0: 17.2 ± 1.8; midazolam/fentanyl-FIO2 0.3: 15.4 ± 1.1; midazolam/fentanyl-FIO2 1.0: 21.0 ± 2.2 mL/kg/min at STP). The RQ was lower at FIO2 1.0 than FIO2 0.3 (isoflurane-FIO2 0.3: 0.80 ± 0.07; isoflurane-FIO2 1.0: 0.71 ± 0.05; midazolam/fentanyl-FIO2 0.3: 0.79 ± 0.03; midazolam/fentanyl-FIO2 1.0: 0.59 ± 0.04). R was not affected by either anesthetics or FIO2. Inspired 100% O2 increased VO2 and decreased RQ, which might be more remarkable when midazolam/fentanyl was used.


PEDIATRICS ◽  
1972 ◽  
Vol 50 (3) ◽  
pp. 361-371
Author(s):  
Elizabeth J. James ◽  
John R. Raye ◽  
Edwin L. Gresham ◽  
Edgar L. Makowski ◽  
Giacomo Meschia ◽  
...  

Metabolic studies were carried out in 22 sheep fetuses free of operative stress. The studies included measurements of umbilical blood flow (175 ± 8 ml/min/kg), fetal oxygen consumption (5.99 ± 0.15 ml/min/kg), carbon dioxide production (5.65 ± 0.17 ml/min/kg), glucose uptake (3.06 ± 0.28 mg/min/kg), respiratory quotient (0.94 ± 0.01), and glucose/oxygen quotient·(0.41 ± 0.03). The studies demonstrated that fetal glucose uptake could be correlated with the glucose concentration difference betsveen maternal arterial and fetal umbilical arterial blood, as well as with maternal arterial glucose concentration. Umbilical arterial glucose concentration was a function of maternal arterial concentration over the concentration range studied. The study demonstrates that the fetal respiratory quotient is significantly less than one. These data suggest that the accumulation of carbon in the fetus for growth represents approximately 40% of the carbon intake in the growing fetal lamb.


2010 ◽  
Vol 53 (3) ◽  
pp. 131-137 ◽  
Author(s):  
Zdeněk Zadák ◽  
Radomír Hyšpler ◽  
Miloslav Hronek ◽  
Alena Tichá

Measurement of parameters of energy requirement, respiratory quotient (RQ), rate of oxygen consumption (VO2) and rate of carbon dioxide production (VCO2) reveal Ringerfundin as an excellent and metabolically stable-acting balanced ionic solution, which does not increase the consumption of O2 or the total energy requirement. In conclusion, Ringerfundin was very well tolerated and in no case were observed undesirable effects.


No method has so far been published for obtaining the respiratory quotient of small pieces of tissue or living organisms the total gas turnover of which in the available experimental period is likely to be of the order of 1/10 cu. mm. In the present paper we shall describe such a method and give details of the results obtained with it on single isolated pieces of the regions of the amphibian gastrula. Dixon (1934) and others have given sufficient reasons for rejecting all methods which do not determine the oxygen consumption and the production of carbon dioxide on the same piece of tissue so that the simplest method on the usual large scale is that of Dickens and Šimer (1930) in which annular cups are used. As this necessitates the use of phosphate buffer solutions, which are regarded as unphysiological for work with mammalian tissues, the later more complicated methods in which bicarbonate is employed came into general use. For the present problem, however, in which thee amphibian embryonic tissues studied remain perfectly normal in Holtfeter solution or even tap or river water, the difficulties caused by bicarbonate were avoided. At the same time, we believe that is should be by no means impossible to adapt the driver manometer to measurements of respiratory quotient even in bicarbonate medium.


Author(s):  
Grażyna Mazurkiewicz-Boroń ◽  
Teresa Bednarz ◽  
Elżbieta Wilk-Woźniak

Microbial efficiency in a meromictic reservoirIndices of microbial efficiency (expressed as oxygen consumption and carbon dioxide release) were determined in the water column of the meromictic Piaseczno Reservoir (in an opencast sulphur mine), which is rich in sulphur compounds. Phytoplankton abundances were low in both the mixolimnion (up to 15 m depth) and monimolimnion (below 15 m depth). In summer and winter, carbon dioxide release was 3-fold and 5-fold higher, respectively, in the monimolimnion than in the mixolimnion. Laboratory enrichments of the sulphur substrate of the water resulted in a decrease in oxygen consumption rate of by about 42% in mixolimnion samples, and in the carbon dioxide release rate by about 69% in monimolimnion samples. Water temperature, pH and bivalent ion contents were of major importance in shaping the microbial metabolic efficiency in the mixolimnion, whilst in the monimolimnion these relationships were not evident.


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