Note on the mathematical theory of oxygen consumption at low oxygen pressures

PROTOPLASMA ◽  
1933 ◽  
Vol 20 (1) ◽  
pp. 125-130 ◽  
Author(s):  
N. Rashevsky
Keyword(s):  
Oxygen Consumption ◽  
Mathematical Theory ◽  
Low Oxygen

scholarly journals The Function of the Gills of Mayfly Nymphs from Different Habitats

1939 ◽  
Vol 16 (3) ◽  
pp. 363-373 ◽  
Author(s):  
C. A. WINGFIELD
Keyword(s):  
Oxygen Consumption ◽  
Oxygen Content ◽  
The Body ◽  
Gaseous Exchange ◽  
Low Oxygen ◽  
Respiratory Mechanism ◽  
Tracheal Gills ◽  
Cloeon Dipterum ◽  
Gill Function ◽  
Oxygen Concentrations

1. The oxygen consumption of normal and gill-less nymphs of the mayflies Baetis sp., Cloeon dipterum and Ephemera vulgata has been measured at various oxygen concentrations. 2. It has been found that over the complete range of oxygen concentrations studied, the tracheal gills do not aid oxygen consumption in Baetis sp. In Cloeon dipterum, at all oxygen concentrations tested, no gaseous exchange takes place through the gills; at low oxygen concentrations, however, the gills function as an accessory respiratory mechanism in ventilating the respiratory surface of the body and so aid oxygen consumption. In Ephemera Vulgata the gills aid oxygen consumption even at high oxygen concentrations. In this species the gills may function both as true respiratory organs and as a ventilating mechanism. 3. It is shown that the differences in gill function can be related to the oxygen content of the habitat of each species.

Embryonic oxygen consumption and growth of Laysan and black-footed albatross

1982 ◽  
Vol 242 (1) ◽  
pp. R121-R128 ◽  
Author(s):  
T. N. Pettit ◽  
G. S. Grant ◽  
G. C. Whittow ◽  
H. Rahn ◽  
C. V. Paganelli
Keyword(s):  
Oxygen Consumption ◽  
Slow Growth ◽  
Egg Mass ◽  
Low Oxygen ◽  
O2 Uptake ◽  
Prolonged Incubation ◽  
Slow Growth Rate ◽  
Air Space ◽  
Embryonic Metabolism ◽  
Pulmonary Respiration

The constraints placed on diffusive gas exchange by the eggshell and the adaptive features of embryonic respiration and metabolism in large Laysan and black-footed albatross eggs (300 g) during prolonged incubation (65 days) were examined in naturally incubated eggs on Sand Island, Midway, in the Northwestern Hawaiian Islands. A low eggshell gas conductance and slow growth rate were associated with a relatively low oxygen consumption (MO2) throughout incubation. Just prior to internal pipping (IP) of the inner shell membrane and penetration of the air space, the MO2 (pre-IP MO2) was approximately 1,250 ml O2 (STPD).day-1 for both species, resulting in air cell O2 and CO2 tensions of 106 and 40 Torr, respectively. During the 4- to 5-day pipping-to-hatching interval, O2 uptake increases rapidly as pulmonary respiration is initiated. Hatchling O2 consumption averaged 3,700 ml O2 (STPD).day-1 or about three times the pre-IP MO2. Data support the hypothesis that embryonic metabolism among Procellariiformes is related to the extent to which the incubation period deviates from the expected value based on initial egg mass.

Oxidative phosphorylation in cardiac infarct. Effect of glucose-KCl-insulin solution

1965 ◽  
Vol 209 (2) ◽  
pp. 371-375 ◽  
Author(s):  
Edmundo Calva ◽  
Adela Mujica ◽  
Abdo Bisteni ◽  
Demetrio Sodi-Pallares
Keyword(s):  
Oxygen Consumption ◽  
Oxidative Phosphorylation ◽  
Respiratory Control ◽  
Low Oxygen ◽  
Normal Limits ◽  
Functional Aspects ◽  
Insulin Solution ◽  
Effect Of Glucose ◽  
Infarcted Tissue ◽  
Electrocardiographic Abnormalities

Myocardial infarction was produced in dogs by ligature of the anterior descending coronary artery. Sarcosomes were isolated from normal and infarcted tissue. Oxygen consumption was followed polarographically and adenosine triphosphate was measured as glucose 6-phosphate. One group of animals received a continuous infusion of glucose for 12 hr; another group received "polarizing solution" (glucose-KCl-insulin). Sarcosomes from the first had a low oxygen consumption, no respiratory control, and no oxidative phosphorylation. In contrast, the administration of glucose-KCl-insulin solution maintained practically within normal limits these functional aspects of the sarcosomes. The reversal of electrocardiographic abnormalities by the administration of the polarizing solution coincided with improvement of such biochemical functions. Anesthesia and surgical handling did not appear to modify the behavior of the sarcosomes.

Selection for high and low oxygen consumption-induced differences in maintenance energy requirements of mice

2016 ◽  
Vol 88 (7) ◽  
pp. 959-965 ◽  
Author(s):  
Hongyu Darhan ◽  
Motoi Kikusato ◽  
Masaaki Toyomizu ◽  
Sang-gun Roh ◽  
Kazuo Katoh ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Energy Requirements ◽  
Maintenance Energy ◽  
Low Oxygen ◽  
Selection For

Comparison of buffer and red blood cell perfusion of guinea pig heart oxygenation

2003 ◽  
Vol 285 (5) ◽  
pp. H1819-H1825 ◽  
Author(s):  
Kenneth A. Schenkman ◽  
Daniel A. Beard ◽  
Wayne A. Ciesielski ◽  
Eric O. Feigl
Keyword(s):  
Oxygen Consumption ◽  
Guinea Pig ◽  
Oxygen Saturation ◽  
Red Blood Cells ◽  
Ventricular Function ◽  
Oxygen Tension ◽  
Blood Cells ◽  
Low Oxygen ◽  
Guinea Pig Heart ◽  
Perfused Hearts

Myocardial mean myoglobin oxygen saturation was determined spectroscopically from isolated guinea pig hearts perfused with red blood cells during increasing hypoxia. These experiments were undertaken to compare intracellular myoglobin oxygen saturation in isolated hearts perfused with a modest concentration of red blood cells (5% hematocrit) with intracellular myoglobin saturation previously reported from traditional buffer-perfused hearts. Studies were performed at 37°C with hearts paced at 240 beats/min and a constant perfusion pressure of 80 cmH2O. It was found that during perfusion with a hematocrit of 5%, baseline mean myoglobin saturation was 93% compared with 72% during buffer perfusion. Mean myoglobin saturation, ventricular function, and oxygen consumption remained fairly constant for arterial perfusate oxygen tensions above 100 mmHg and then decreased precipitously below 100 mmHg. In contrast, mean myoglobin saturation, ventricular function, and oxygen consumption began to decrease even at high oxygen tension with buffer perfusion. The present results demonstrate that perfusion with 5% red blood cells in the perfusate increases the baseline mean myoglobin saturation and better preserves cardiac function at low oxygen tension relative to buffer perfusion. These results suggest that caution should be used in extrapolating intracellular oxygen dynamics from buffer-perfused to blood-perfused hearts.

RESPIRATION OF FISHES WITH SPECIAL EMPHASIS ON STANDARD OXYGEN CONSUMPTION: III. INFLUENCE OF OXYGEN

1964 ◽  
Vol 42 (3) ◽  
pp. 355-366 ◽  
Author(s):  
F. W. H. Beamish
Keyword(s):  
Oxygen Consumption ◽  
Oxygen Uptake ◽  
Partial Pressure ◽  
Brook Trout ◽  
Low Oxygen ◽  
Low Level ◽  
Standard Metabolism ◽  
Partial Pressures ◽  
Rate Of Oxygen Consumption ◽  
Standard Rate

Standard oxygen consumption was determined in relation to various partial pressures of oxygen for eastern brook trout at 10° and 15 °C, and for carp and goldfish at 10° and 20 °C. Two conditions of oxygen acclimation were compared. In one case acclimation was to air saturation while in the other acclimation was to each of the partial pressures of oxygen applied.Down to a partial pressure of oxygen of approximately 80 mm Hg, standard oxygen uptake remained approximately constant, and further, the rates for the two differently acclimated groups were about equal. Below 80 mm Hg the standard rate first increased to a maximum and then, with a further reduction in the partial pressure, decreased. Below 80 mm Hg the standard rate of oxygen consumption was in all cases less for the fish acclimated to the low level of oxygen than for those acclimated to air saturation.Comparison of standard and active values suggests that the increase in standard rate of oxygen uptake in response to low oxygen does not reach the active level as suggested earlier by Fry (1947). The suggestion is made that a fraction of standard metabolism is derived anaerobically in low levels of oxygen. Further, it appears that acclimation to a low level of oxygen enhances the anaerobic fraction of standard metabolism.

Temperature acclimation influences temperature-related behaviour as well as oxygen-transport physiology and biochemistry in the water flea Daphnia magna

2003 ◽  
Vol 81 (2) ◽  
pp. 237-249 ◽  
Author(s):  
Tobias Lamkemeyer ◽  
Bettina Zeis ◽  
Rüdiger J Paul
Keyword(s):  
Oxygen Consumption ◽  
Daphnia Magna ◽  
Oxygen Concentration ◽  
Oxygen Transport ◽  
Oxygen Affinity ◽  
Low Oxygen ◽  
High Concentration ◽  
Water Flea ◽  
Two Dimensional Gel Electrophoresis ◽  
Physiology And Biochemistry

To evaluate the role of temperature in oxygen transport in the water flea Daphnia magna, temperature-related behaviour as well as oxygen-transport physiology and biochemistry were investigated in animals long-term acclimated to moderate temperatures: 10, 20, or 30°C (normoxia) or 20°C (hypoxia). Study of the behaviour of animal groups within a normoxic thermal gradient showed their preferred temperatures and distribution patterns to be connected with acclimation conditions; for example, cold-acclimated individuals, with their relatively high metabolic rates and low oxygen-transport capacities, crowded at low temperatures where the oxygen concentration was high. One key to explaining these data is to assume a strategy of avoiding oxygen shortage. Both temperature and hypoxia acclimation also modified oxygen-transport variables such as oxygen consumption, ventilation and circulation rates, or the concentration and oxygen affinity of haemoglobin. Characteristic features of cold-acclimated D. magna were relatively high oxygen-consumption and heart rates and a low concentration and oxygen affinity of haemoglobin. Hypoxia-acclimated D. magna showed relatively low convective rates (frequency of thoracic-limb movements, heart rate) but a high concentration and oxygen affinity of haemoglobin. Additional experiments showed that independently of each other, temperature and ambient oxygen concentration modify haemoglobin quantity and quality, the former possibly acting via a temperature-induced hypoxia. The varying oxygen affinity is probably due to alterations of haemoglobin subunit composition, with the particular participation of subunits A, E, and G as revealed by two-dimensional gel electrophoresis.

On the Biology of Calanus finmarchicus. Part VI. Oxygen Consumption in Relation to Environmental Conditions

1935 ◽  
Vol 20 (1) ◽  
pp. 1-27 ◽  
Author(s):  
S. M. Marshall ◽  
A. G. Nicholls ◽  
A. P. Orr
Keyword(s):  
Oxygen Consumption ◽  
Environmental Conditions ◽  
Harmful Effect ◽  
Ion Concentration ◽  
Calanus Finmarchicus ◽  
Continuous Exposure ◽  
Low Oxygen ◽  
Hydrogen Ion Concentration ◽  
Oxygen Utilisation ◽  
Striking Effect

SUMMARY1. Experiments have been done to determine the oxygen utilisation by male, female and Stage V Calanus under different environmental conditions.2. An initial fall in the respiration of adult Calanus was observed during the first few hours after capture. Stage V do not show this clearly. It is found more often in winter than in summer.3. The lethal temperature varies from 24° C. in winter to 26° C. in summer. Stage V Calanus are more resistant to high temperatures than adults.4. Respiration rises with increase of temperature from 0° C. to 20° C. The increase does not follow van't Hoff's law. The oxygen consumption of males and females is about the same, while that of Stage V is lower. Above 20° C. there is a harmful effect.5. Within the limits studied (pH 7.4–pH 8.5) change in hydrogen-ion concentration has no effect on respiration.6. Calanus are unaffected by an increase in the oxygen content of the water, but are sensitive to low oxygen tensions. Below a concentration of about 3 ml. per litre the respiration decreases. At concentrations between 1 and 2 ml. per litre they are killed. They are more resistant at 5° C. than at 15° C. and Stage V are more resistant than adults at both these temperatures.7. Calanus can become acclimatised to salinities as low as 35–40% seawater (S=12‰–13.6‰), but their respiration is lowered at a salinity of 50%.8. Light has a striking effect on Calanus. It may increase the respiration by 100% or more. This effect can be detected also in the sea, but not below 5 metres. Continuous exposure to light is harmful.9. The bearing of these results on the distribution of Calanus is discussed.10. From the amount of oxygen used in respiration, calculations of the food required are made and these are compared with the results given by Putter for Calanus and other copepods.

Pelagic oxygen consumption rates in the Elbe estuary: Proxies and spatial patterns.

2021 ◽  
Author(s):  
Justus E.E. van Beusekom ◽  
Dorothee Fehling ◽  
Sina Bold ◽  
Tina Sanders
Keyword(s):  
Organic Matter ◽  
Oxygen Consumption ◽  
Land Reclamation ◽  
Salinity Gradient ◽  
Elbe Estuary ◽  
Low Oxygen ◽  
Port Area ◽  
Consumption Rates ◽  
Gradient Based ◽  
The Elbe River

<div> <div><span>The Elbe estuary is strongly impacted by human activities including dredging, land reclamation and eutrophication. Since about 30 years, water quality improved leading to major phytoplankton blooms in the Elbe river. When these blooms enter the upper estuary including the Hamburg port area, they collapse leading  to low oxygen conditions. During a cruise in September 2020 we measured oxygen consumption rates in water samples of the Elbe Estuary between the coastal North Sea (Wadden Sea) and  the weir in Geesthacht including a large freshwater part of the Elbe estuary. In addition, suspended matter samples were taken and analysed for chlorophyll, particulate C (PC) and particulate N (PN). Oxygen consumption rates reached maximum values at both the marine side (~0.3 µmol/(l*h)) and the freshwater  side of the estuary (~0.65 µmol/(l*h)) and a distinct minimum near the Estuarine Turbidity Maximum near the onset of the salinity gradient. Based on specific weights of phytoplankton and PC content, we estimated the contribution of newly formed organic matter. This estimate correlated significantly with the observed oxygen consumption rates. We suggest that most of the riverine organic matter is degraded within the freshwater part of the Elbe estuary before reaching the salinity gradient. This is in line with significant amounts of nitrate being released within the freshwater part of the estuary.</span></div> </div>

Blood flow and oxygen consumption in avian skeletal muscle during hypoxia

1981 ◽  
Vol 50 (2) ◽  
pp. 450-455 ◽  
Author(s):  
B. R. Grubb
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Oxygen Consumption ◽  
Flow Rate ◽  
Blood Flow Rate ◽  
Oxygen Extraction ◽  
Arterial Oxygen ◽  
Low Oxygen ◽  
Arterial Oxygen Content ◽  
Hindlimb Muscle

Birds are known to be much more tolerant than mammals to high altitude [low oxygen pressure (PO2)], and it is therefore of interest to know the responses of their muscles to low oxygen. We studied the influence of hypoxia on the rate of blood flow, oxygen extraction, and oxygen consumption (VO2) in resting hindlimb muscle of ducks. We found that during normoxia the VO2 in this muscle mass was similar to resting mammalian red muscle. However, blood flow rate (45 ml x 100 g-1 x min-1) and venous PO2 (70 Torr) were much higher than in resting red or white mammalian muscle. Hypoxia down to 35-40 Torr resulted in no change in blood flow, but oxygen extraction increased dramatically as arterial PO2 fell below 70 Torr. The resting VO2 was maintained even at the lowest arterial oxygen content (5 ml/100 ml). From these experiments it appears as though duck skeletal muscle has a "luxuriant" resting blood flow rate that is sufficient to supply skeletal muscle with adequate oxygen.

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