OXYGEN SUPPLY AND PERFORMANCE IN PEROMYSCUS: METABOLIC AND CIRCULATORY RESPONSES TO EXERCISE

1967 ◽  
Vol 45 (3) ◽  
pp. 531-541 ◽  
Author(s):  
Neri P. Segrem ◽  
J. S. Hart
Keyword(s):  
Oxygen Consumption ◽  
Partial Pressure ◽  
Oxygen Supply ◽  
Peromyscus Leucopus ◽  
Work Rate ◽  
Air Pressure ◽  
Partial Pressure Of Oxygen ◽  
Running Speed ◽  
Adult Mice ◽  
And Performance

Adult mice, Peromyscus leucopus novaboracensis, were exercised on a treadmill at various running speeds up to the highest obtainable at levels of oxygen ranging from 60 to 196 mm Hg. Oxygen consumption was not directly proportional to work rate as found in man and dog, and declined with a fall in the partial pressure of oxygen [Formula: see text] at the same work rate. As noted in other species, dependence of oxygen consumption on oxygen supply in Peromyscus varied with the level of exertion. The uptake at the highest speed was reduced by a relatively small fall in [Formula: see text] below normal air pressure whereas the uptake in resting mice was relatively insensitive to a reduction in [Formula: see text]. Heart rates varied in proportion to running speed and to oxygen consumption and were increased by a fall in [Formula: see text] at the same running speed.

OXYGEN SUPPLY AND PERFORMANCE IN PEROMYSCUS: COMPARISON OF EXERCISE WITH COLD EXPOSURE

1967 ◽  
Vol 45 (3) ◽  
pp. 543-549 ◽  
Author(s):  
Neri P. Segrem ◽  
J. S. Hart
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Body Temperature ◽  
Oxygen Uptake ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Cold Exposure ◽  
Temperature Regulation ◽  
Oxygen Supply ◽  
And Performance

Oxygen consumption, heart rate, and body temperature were measured at temperatures ranging from 27 °C to −28 °C and at oxygen partial pressure [Formula: see text] levels from 60 to 196 mm Hg. Temperature regulation and O2 uptake were progressively limited by reduction of [Formula: see text]. Limitation of O2 consumption by O2 supply was similar to that seen during exercise. The highest oxygen uptake during exposure to cold was greater than during exercise at the higher levels of [Formula: see text].

RESPIRATION OF FISHES WITH SPECIAL EMPHASIS ON STANDARD OXYGEN CONSUMPTION: IV. INFLUENCE OF CARBON DIOXIDE AND OXYGEN

1964 ◽  
Vol 42 (5) ◽  
pp. 847-856 ◽  
Author(s):  
F. W. H. Beamish
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Consumption ◽  
Partial Pressure ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Partial Pressure Of Oxygen ◽  
Partial Pressures ◽  
Rate Of Oxygen Consumption ◽  
Standard Rate ◽  
Different Levels

Oxygen consumption was determined in relation to spontaneous activity and standard metabolism estimated by extrapolating the values to zero activity, Standard oxygen consumption was determined in relation to different partial pressures of carbon dioxide and oxygen for brook trout. Salvelinus fontinalis (Mitchill), at 10 °C, and carp, Cyprinus carpio Linnaeus, at 25 °C. In general, at each partial pressure of oxygen applied, standard oxygen consumption did not change significantly over the range of partial pressures of carbon dioxide followed. The relation for brook trout operated on a level characteristic of the partial pressure of oxygen. Although the effect of different levels of oxygen was not established for carp at 25 °C, it is presumed that the relation operated also in that species in a similar way.Acclimation to the different levels of carbon dioxide and oxygen to be tested was examined and, ordinarily, found not to change significantly the standard rate of oxygen consumption.

The effect of air pressure on the growth of Candida lipolytica on n-hexadecane

1969 ◽  
Vol 15 (11) ◽  
pp. 1255-1261 ◽  
Author(s):  
M. Wayman ◽  
E. Wein
Keyword(s):  
Mass Transfer ◽  
Partial Pressure ◽  
Cell Mass ◽  
Air Pressure ◽  
Candida Lipolytica ◽  
Partial Pressure Of Oxygen ◽  
Gaseous Component ◽  
Air Stream ◽  
Pressure Maximum ◽  
Maximum Cell

Mass transfer of oxygen to the microbial cell is very important in hydrocarbon fermentations. One method of increasing mass transfer of oxygen is to increase its partial pressure. Increasing the total pressure of the air-feed will increase the partial pressure of oxygen, but little work has been done in this area. The present study concerns the effects of increased air pressure up to 100 pounds per square inch gauge (p.s.i.g.) on the growth of Candida lipolytica on n-hexadecane in an agitated 7-liter pressure reactor. Inhibited growth was observed with increasing pressure. Maximum cell mass yield at 100 p.s.i.g. was about one-third that at 15 p.s.i.g. Inhibition was attributed to a gaseous component fed in with the air stream.

scholarly journals The Physiological Action of Abnormally High Temperatures on Poikilotherm Animals

1940 ◽  
Vol 17 (4) ◽  
pp. 386-395
Author(s):  
G. S. FRAENKEL ◽  
G. V. B. HERFORD
Keyword(s):  
Oxygen Consumption ◽  
High Temperature ◽  
Partial Pressure ◽  
High Temperatures ◽  
Oxygen Pressure ◽  
Partial Pressure Of Oxygen ◽  
Waste Products ◽  
Physiological Action ◽  
Very High ◽  
Acid Waste

The oxygen consumption of blowfly larvae at sublethal and lethal high temperatures at the beginning of the determination is entirely dependent on the oxygen pressure, but after about 1 hr. at 42°C. it is higher at 20 and 10% partial pressure of oxygen than at either 100 or 5%. Death at high temperatures is not due to lack of oxygen, but may be due to the accumulation of acid waste products of the metabolism. The basal oxygen consumption remains unchanged for some time after the organism has been irreversibly injured by the high temperature. Blowfly larvae resist the damaging effect of high temperatures slightly better in air (20% oxygen) than in either very high (100%) or very low (less than 10%) concentrations of oxygen.

Myocardial developed tension and oxygen supply

1964 ◽  
Vol 207 (2) ◽  
pp. 341-346 ◽  
Author(s):  
Eugene A. Lentini
Keyword(s):  
Skeletal Muscle ◽  
Partial Pressure ◽  
Heart Muscle ◽  
Oxygen Supply ◽  
Mechanical Response ◽  
Gas Mixture ◽  
Partial Pressure Of Oxygen ◽  
D Value

The isometric developed tension of rat's trabecula carnea was recorded, in vitro. The magnitude of the developed tension was observed to be directly a function of the partial pressure of oxygen in the aerating mixture. This activity reached a maximum at pO2 values of 700 mm Hg. Fluctuations in the developed tension were noted during the 1st hr of the experiment; insignificant changes with noted exceptions occurred during the 2nd and 3rd hr. The data indicate that the mechanical response of the tissue is a function of both duration of the experiment and aerating gas mixture. The diflusion coefficient ( D') of oxygen through the preparation was calculated. The results indicate that the D' value for heart muscle may be larger than that of skeletal muscle as determined by Krogh.

Interaction of H2O, O2 and H2 with Proton Conducting Oxides Based on Lanthanum Scandates

2019 ◽  
pp. 88-100
Author(s):  
A. S. Farlenkov ◽  
N. A. Zhuravlev ◽  
Т. A. Denisova ◽  
М. V. Ananyev
Keyword(s):  
Water Vapor ◽  
Partial Pressure ◽  
Gas Phase ◽  
Molecular Hydrogen ◽  
Proton Magnetic Resonance ◽  
Partial Pressure Of Oxygen ◽  
Proton Conducting ◽  
Conducting Oxides ◽  
Temperature Range ◽  
Apparent Level

The research uses the method of high-temperature thermogravimetric analysis to study the processes of interaction of the gas phase in the temperature range 300–950 °C in the partial pressure ranges of oxygen 8.1–50.7 kPa, water 6.1–24.3 kPa and hydrogen 4.1 kPa with La1–xSrxScO3–α oxides (x = 0; 0.04; 0.09). In the case of an increase in the partial pressure of water vapor at a constant partial pressure of oxygen (or hydrogen) in the gas phase, the apparent level of saturation of protons is shown to increase. An increase in the apparent level of saturation of protons of the sample also occurs with an increase in the partial pressure of oxygen at a constant partial pressure of water vapor in the gas phase. The paper discusses the causes of the observed processes. The research uses the hydrogen isotope exchange method with the equilibration of the isotope composition of the gas phase to study the incorporation of hydrogen into the structure of proton-conducting oxides based on strontium-doped lanthanum scandates. The concentrations of protons and deuterons were determined in the temperature range of 300–800 °C and a hydrogen pressure of 0.2 kPa for La0.91Sr0.09ScO3–α oxide. The paper discusses the role of oxygen vacancies in the process of incorporation of protons and deuterons from the atmosphere of molecular hydrogen into the structure of the proton conducting oxides La1–xSrxScO3–α (x = 0; 0.04; 0.09). The proton magnetic resonance method was used to study the local structure in the temperature range 23–110 °C at a rotation speed of 10 kHz (MAS) for La0.96Sr0.04ScO3–α oxide after thermogravimetric measurements in an atmosphere containing water vapor, and after exposures in molecular hydrogen atmosphere. The existence of proton defects incorporated into the volume of the investigated proton oxide from both the atmosphere containing water and the atmosphere containing molecular hydrogen is unambiguously shown. The paper considers the effect of the contributions of the volume and surface of La0.96Sr0.04ScO3–α oxide on the shape of the proton magnetic resonance spectra.

Glycogenolytic rates and cAMP in livers of rats running at different treadmill speeds

1983 ◽  
Vol 245 (3) ◽  
pp. R353-R356
Author(s):  
W. W. Winder ◽  
M. A. Beattie ◽  
E. O. Fuller
Keyword(s):  
Liver Glycogen ◽  
Work Rate ◽  
Curvilinear Relationship ◽  
Camp Concentration ◽  
Running Speed ◽  
Cyclic Monophosphate ◽  
High Degree ◽  
The Relationship ◽  
Camp Levels ◽  
Liver Glycogenolysis

The purposes of this study were to determine the effect of different work rates on the rate of liver glycogenolysis and to determine the relationship between liver adenosine 3',5'-cyclic monophosphate (cAMP) levels and the glycogenolytic rate. Rats were run at treadmill speeds ranging from 10 to 34 m/min up a 15% grade for either 30 or 60 min. Both the magnitude of the decrease in liver glycogen and the increase in hepatic cAMP were dependent on the running speed and the duration of running. At the highest work rate a disproportionate acceleration in the liver glycogenolytic rate was observed compared with that at lower work loads, thus resulting in a curvilinear relationship between work rate and liver glycogenolytic rate. A high degree of correlation was found between the liver glycogenolytic rate and hepatic cAMP concentration (r = 0.98). This observation is consistent with the idea that hepatic glycogenolytic rates are determined by cAMP-mediated mechanisms.

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