scholarly journals CO2 Permeability of Rat Hepatocytes and Relation of CO2 Permeability to CO2 Production

2018 ◽  
Vol 46 (3) ◽  
pp. 1198-1208 ◽  
Author(s):  
Mariela Arias-Hidalgo ◽  
Qinggong Yuan ◽  
Fabrizio Carta ◽  
Claudiu T. Supuran ◽  
Gerolf Gros ◽  
...  
Keyword(s):  
Rat Hepatocytes ◽  
Organic Cation Transporter ◽  
Co2 Production ◽  
O2 Consumption ◽  
Low Co2 ◽  
Positive Linear Correlation ◽  
Rate Of Oxygen Consumption ◽  
Membrane Permeabilities ◽  
Intermediate Rate ◽  
Very High

Background/Aims: It has been described that cells in culture with very low oxidative metabolism possess a low CO2 membrane permeability, PCO2, of ∼ 0.01 cm/s. On the other hand, cardiomyocytes and mitochondria with extremely high rates of O2 consumption exhibit very high CO2 membrane permeabilities of 0.1 and 0.3 cm/s, repectively. To ascertain that this represents a systematic relationship, we determine here PCO2 of hepatocytes, which exhibit an intermediate rate of O2 consumption. Methods: We isolated intact hepatocytes with vitalities of ∼ 70% from rat liver and measured their CO2 permeability by the previously published mass spectrometric 18O exchange technique. Results: We find a PCO2 of hepatocytes of 0.03 cm/s in the presence of FC5-208A and verapamil. FC5-208A was necessary to inhibt extracellular carbonic anhydrase, and verapamil was necessary to inhibit intracellular uptake of FC5-208A by the organic cation transporter OCT1 of hepatocytes. Conclusion: Rat hepatocytes with their intermediate rate of oxygen consumption also possess an intermediate CO2 permeability. From pairs of data for five types of cells/organelles, we find an excellent positive linear correlation between PCO2 and metabolic rate, suggesting an adaptation of PCO2 to the rate of O2 consumption.

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.

Chloral Hydrate and the Carbon Dioxide Chemoreceptor Response: A Study of Puppies and Infants

PEDIATRICS ◽  
1982 ◽  
Vol 70 (3) ◽  
pp. 447-450
Author(s):  
Martin H. Lees ◽  
George D. Olsen ◽  
Kip L. McGilliard ◽  
James D. Newcomb ◽  
Cecille O. Sunderland
Keyword(s):  
Carbon Dioxide ◽  
Tidal Volume ◽  
Eye Movement ◽  
Chloral Hydrate ◽  
Nrem Sleep ◽  
Co2 Production ◽  
O2 Consumption ◽  
Rapid Eye Movement ◽  
Natural Sleep ◽  
Co2 Elimination

CO2 chemoreceptor function was assessed during natural sleep and following the administration of 100 mg/kg of chloral hydrate to 26 puppies. With chloral hydrate-induced sleep, there were no significant changes in ventilation or in CO2 chemoreceptor response. The ventilation and CO2 chemoreceptor response of a group of infants in natural sleep were compared with those of a group receiving 50 mg/kg of chloral hydrate. Tidal volume, O2 consumption, and CO2 elimination were slightly higher in the group given chloral hydrate. There was no difference in the CO2 chemoreceptor response. The proportion of time spent in rapid eye movement (REM) and non-rapid eye movement (NREM) sleep in chloral hydrate-induced sleep was similar to that occurring in natural sleep. Use of chloral hydrate stabilizes O2 consumption and CO2 production, and it greatly facilitates the assessment of chemoreceptor function in infants. The CO2 chemoreceptor response appears not to be altered in puppies or infants.

scholarly journals Tequila Still Distillation Fractioned Residual Streams for Use in Biorefinery

Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6222
Author(s):  
Edgardo Martinez-Orozco ◽  
Pablo Gortares-Moroyoqui ◽  
Norberto Santiago-Olivares ◽  
Juan Napoles-Armenta ◽  
Ruth Gabriela Ulloa-Mercado ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Gas Chromatography ◽  
Energy Analysis ◽  
Oxygen Demand ◽  
Solid Content ◽  
Co2 Production ◽  
Second Stage ◽  
Stage Process ◽  
Very High ◽  
Tequila Vinasses

Tequila vinasses is a mixture made from up to six still distillation two-stage process residual effluents. First stage fractions: residual must (60%), heads (0.9%) and tails (20.0%); second stage fractions: non-evaporated (8.0%), heads (0.1%) and tails (1.0%); the result is a more complex effluent for its treatment or biorefining. The objectives of this study were to: (a) characterize the five still distillation volatile streams in the Tequila 100% Agave processing; compounds: methanol, ethanol, acetaldehyde, ethyl acetate, sec-butanol, n-propanol, iso-butanol, n-butanol, iso-amyl, n-amyl, and ethyl lactate were detected by gas chromatography; calculated chemical oxygen demand from chemical composition had very high values (53,760–1,239,220 mg/L); measurement of pH (3.24–4.80), color (38.6 UC Pt-Co max), turbidity (46.1 max), electrical conductivity (3.30–172.20 μS/cm), and solid content (0 mg/L) was also made; (b) report an energy analysis (2.02 × 109 KWh) and CO2 production (429 × 106 kg) in the Tequila industry during 2019; (c) up to date residues (365.2 × 106 kg agave bagasse, 1146.1 × 106 kg agave leaves and 3300.0 × 106 L agave vinasse) in 2019; (d) economic analysis, current tequila vinasses treatment price is 16.00 USD/m3 but could reach a considerable fraction value if is bio-refined, a break down component analysis reach for five volatile streams $51.23–$140.00 USD/m3.

Fast-response whole body indirect calorimeters for infants

1993 ◽  
Vol 74 (1) ◽  
pp. 476-484 ◽  
Author(s):  
J. K. Moon ◽  
C. L. Jensen ◽  
N. F. Butte
Keyword(s):  
Eye Movement ◽  
Fast Response ◽  
Full Term ◽  
Whole Body ◽  
Co2 Production ◽  
Sleep Stages ◽  
System Response ◽  
O2 Consumption ◽  
Rapid Eye Movement ◽  
Term Infants

Portable whole body indirect calorimeters were constructed for full-term (2.5- to 8-kg) and preterm (1- to 2.5-kg) infants. A new calibration system significantly increased the accuracy of flowmeters and gas analyzers. Performance tests with N2 and CO2 infusions and butane combustion demonstrated that the error of individual measurements of O2 consumption and CO2 production were within +/- 2%. The measured error was close to the theoretical uncertainty of approximately +/- 1% calculated from test results of the flowmeters and gas analyzers. System response to a step change in butane combustion rate exceeded 90% within 2 min. Error of +/- 2% and response of 2 min are likely to be the practical lower limits for whole body infant indirect calorimeters with current technology. The calorimeters demonstrated a rapid increase in O2 consumption after feeding (preterm infants) and in the transition from non-rapid-eye-movement to rapid-eye-movement sleep stages (full-term infants).

Effects of glycogen depletion and work load on postexercise O2 consumption and blood lactate

1979 ◽  
Vol 47 (3) ◽  
pp. 514-521 ◽  
Author(s):  
S. S. Segal ◽  
G. A. Brooks
Keyword(s):  
Blood Lactate ◽  
Slow Component ◽  
Minute Ventilation ◽  
Co2 Flux ◽  
Work Load ◽  
Bicycle Ergometer ◽  
Co2 Production ◽  
O2 Consumption ◽  
Glycogen Depletion ◽  
Heavy Exercise

To study a possible relationship between blood lactate and O2 consumption (VO2) after exercise, 11 male subjects exercised on a bicycle ergometer at moderate and heavy work loads in both normal glycogen and glycogen-depleted states. At rest, glycogen depletion resulted in significantly lowered blood glucose and lactate concentrations, CO2 production (VCO2), respiratory exchange ratio (R), and minute ventilation (VE). With the exception of glucose, these variables changed more in response to heavy exercise (HE: 2 min at a mean of 1,750 kg.m/min) than to moderate exercise (ME: 2 min at a mean of 1,000 kg.m/min). At either work load, VCO2, R, and lactate showed consistently greater responses in the normal glycogen state. The slope of the initial component of the postexercise VO2 curve was unaffected by either work load or lactate. Although the slope of the slow component of the postexercise VO2 curve became significantly more negative after HE, it was unaffected by the level of lactate. These results are inconsistent with the hypothesis of a “lactacid O2 debt.” Exercise intensity was the predominant factor influencing the magnitude and kinetics of postexercise VO2. Glycogen depletion resulted in lower VCO2, R, and blood lactate, but higher VE during heavy exercise. The results suggest that factors, in addition to CO2 flux to the lungs, influence VE during exercise.

Photosynthetic utilisation of inorganic carbon and its regulation in the marine diatom Skeletonema costatum

2004 ◽  
Vol 31 (10) ◽  
pp. 1027 ◽  
Author(s):  
Xiongwen Chen ◽  
Kunshan Gao
Keyword(s):  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Skeletonema Costatum ◽  
Co2 Concentration ◽  
Marine Diatom ◽  
Disulfonic Acid ◽  
High Co2 ◽  
Low Co2 ◽  
Diatom Skeletonema Costatum ◽  
Very High

Photosynthetic uptake of inorganic carbon and regulation of photosynthetic CO2 affinity were investigated in Skeletonema costatum (Grev.) Cleve. The pH independence of K1/2(CO2) values indicated that algae grown at either ambient (12 μmol L–1) or low (3 μmol L–1) CO2 predominantly took up CO2 from the medium. The lower pH compensation point (9.12) and insensitivity of photosynthetic rate to di-isothiocyanatostilbene disulfonic acid (DIDS) indicated that the alga had poor capacity for direct HCO3– utilisation. Photosynthetic CO2 affinity is regulated by the concentration of CO2 rather than HCO3–, CO32– or total dissolved inorganic carbon (DIC) in the medium. The response of photosynthetic CO2 affinity to changes in CO2 concentration was most sensitive within the range 3–48 μmol L–1 CO2. Light was required for the induction of photosynthetic CO2 affinity, but not for its repression, when cells were shifted between high (126 μmol L–1) and ambient (12 μmol L–1) CO2. The time needed for cells grown at high CO2 (126 μmol L–1) to fully develop photosynthetic CO2 affinity at ambient CO2 was approximately 2 h, but acclimation to low or very low CO2 levels (3 and 1.3 μmol L–1, respectively) took more than 10 h. Cells grown at low CO2 (3 μmol L–1) required approximately 10 h for repression of all photosynthetic CO2 affinity when transferred to ambient or high CO2 (12 or 126 μmol L–1, respectively), and more than 10 h at very high CO2 (392 μmol L–1).

Respiratory stimulation by female hormones in awake male rats

1991 ◽  
Vol 71 (1) ◽  
pp. 37-42 ◽  
Author(s):  
K. Tatsumi ◽  
M. Mikami ◽  
T. Kuriyama ◽  
Y. Fukuda
Keyword(s):  
Tidal Volume ◽  
Ventilatory Response ◽  
Blood Gases ◽  
Male Rats ◽  
Co2 Production ◽  
Male Rat ◽  
O2 Consumption ◽  
Estradiol Treatment ◽  
Respiratory Stimulation ◽  
Ventilatory Response To Co2

The respiratory effect of progestin differs among various animal species and humans. The rat does not hyperventilate in response to exogenous progestin. The present study was conducted to determine whether administration of combined progestin and estrogen prompts ventilatory stimulation in the male rat. Ventilation, blood gases, and metabolic rates (O2 consumption and CO2 production) were measured in the awake and unrestrained male Wistar rat. The combined administration of a synthetic potent progestin (TZP4238) and estradiol for 5 days significantly increased tidal volume and minute expiratory ventilation (VE), reduced arterial PCO2, and enhanced the ventilatory response to CO2 inhalation (delta VE/delta PCO2). On the other hand, respiratory frequency, O2 consumption, CO2 production, and body temperature were not affected. The arterial pH increased slightly, with a concomitant decrease in plasma [HCO3-]. Administration of either TZP4238 or estradiol alone or vehicle (Tween 80) had no effect on respiration, blood gases, and ventilatory response to CO2. The results indicated that respiratory stimulation following combined progestin plus estradiol treatment in the male rat involves activation of process(es) that regulate tidal volume and its augmentation during CO2 stimulus.

CHANGES IN VENTILATION, O2 CONSUMPTION AND CO2 PRODUCTION DURING RECOVERY FROM ISOFLURANE ANESTHESIA

1986 ◽  
Vol 65 (Supplement 3A) ◽  
pp. A527 ◽  
Author(s):  
M. J. Ciofolo ◽  
F. Clergue ◽  
C. Devilliers ◽  
M. Ben Ammar ◽  
P. Viars
Keyword(s):  
Co2 Production ◽  
O2 Consumption ◽  
Isoflurane Anesthesia
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