Circulation, oxygen transport, and activity in the crayfish

1981 ◽  
Vol 240 (1) ◽  
pp. R99-R105 ◽  
Author(s):  
P. S. Rutledge
Keyword(s):  
Cardiac Output ◽  
Oxygen Uptake ◽  
Stroke Volume ◽  
Oxygen Transport ◽  
Uptake Rate ◽  
Oxygen Uptake Rate ◽  
Maximum Activity ◽  
Active Oxygen ◽  
Routine Activity ◽  
Fick Principle

Heart and ventilation frequencies, oxygen uptake rate, hemocyanin concentration, and pre- and postbranchial PO2 and pH were measured in unrestrained crayfish (Pacifastacus leniuculus) immediately following routine and forced (maximum) activity. Experiments were performed at 20 degrees C, the temperature of maximum scope for activity in this species, and at 10 and 25 degrees C. A procedure for using N-ethylmaleimide as an anticoagulant in hemolymph sampling is described. Hemocyanin oxygen saturation, oxygen content of pre- and postbranchial hemolymph, cardiac output, and stroke volume were estimated from the measured parameters. PO2 of postbranchial hemolymph sampled immediately after routine activity was low (9-12 Torr), accompanied by hemocyanin oxygen saturations of 55-75%. Maximum forced activity for 10 min caused further reduction in these values. Thus hemocyanin is apparently not usually saturated with oxygen in these crayfish. Cardiac output, as estimated by the Fick principle, was high (at 20 degrees C, 236 ml x kg-1 x min-1 for routine activity and 969 ml x kg-1 x min-1 for forced activity). Evidence is presented that ventilation, rather than circulation, limits active oxygen uptake and scope for activity both above and below 20 degrees C.

scholarly journals Study of influence of oxygen transport conditions on oxygen uptake rate of Pseudomonas putida CECT5279 cultures

2009 ◽  
Vol 25 ◽  
pp. S216
Author(s):  
S. Escobar Parra ◽  
E. Gomez Castro ◽  
V.E. Santos Mazorra ◽  
F. Garcia-Ochoa Soria
Keyword(s):  
Oxygen Uptake ◽  
Pseudomonas Putida ◽  
Oxygen Transport ◽  
Uptake Rate ◽  
Oxygen Uptake Rate

Differences between directly measured and calculated values for cardiac output in the dogfish: a criticism of the Fick method

1982 ◽  
Vol 99 (1) ◽  
pp. 255-268
Author(s):  
J. D. Metcalfe ◽  
P. J. Butler
Keyword(s):  
Cardiac Output ◽  
Oxygen Uptake ◽  
Stroke Volume ◽  
Complete Control ◽  
Fick Principle ◽  
Scyliorhinus Canicula ◽  
Respiratory Surface ◽  
Significant Difference ◽  
Cardiac Bypass ◽  
Cardiac Stroke Volume

Cardiac output has been measured directly, and calculated by the Fick method, during normoxia and hypoxia in six artificially perfused dogfish (Scyliorhinus canicula) in an attempt to estimate the accuracy of this method in fish. The construction and operation of a simple extra-corporeal cardiac bypass pump is described. This pump closely mimics the flow pulse profiles of the fish's own heart and allows complete control of both cardiac stroke volume and systolic and diastolic periods. During normoxia (PO2 = 21 kPa) there was no significant difference between directly measured and calculated values for cardiac output. However, some shunting of blood past the respiratory surface of the gills may have been obscured by cutaneous oxygen uptake. In response to hypoxia (PO2 = 8.6 kPa) there is either a decrease in the amount of blood being shunted past the respiratory surface of the gills and/or an increase in cutaneous oxygen uptake such that the Fick calculated value for cardiac output is on average 38% greater than the measured value. It is proposed that the increase in the levels of circulating catecholamines that is reported to occur in response to hypoxia in this species may play an important role in the observed response to hypoxia. The results are discussed in terms of their implications for the calculation of cardiac output by the Fick principle in fish.

Exposure to degraded coral habitat depresses oxygen uptake rate during exercise of a juvenile reef fish

Coral Reefs ◽  
2021 ◽  
Author(s):  
Adam T. Downie ◽  
Caroline M. Phelps ◽  
Rhondda Jones ◽  
Jodie L. Rummer ◽  
Douglas P. Chivers ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Reef Fish ◽  
Uptake Rate ◽  
Oxygen Uptake Rate ◽  
Juvenile Reef Fish

Mass transfer impacts in flocculent and granular biomass from SBR systems

2004 ◽  
Vol 50 (10) ◽  
pp. 203-212 ◽  
Author(s):  
D. Gapes ◽  
B.-M. Wilén ◽  
J. Keller
Keyword(s):  
Mass Transfer ◽  
Particle Size ◽  
Oxygen Uptake ◽  
Activated Sludge ◽  
Uptake Rate ◽  
Oxygen Uptake Rate ◽  
Batch Reactor ◽  
Average Particle Size ◽  
Gas Analysis ◽  
Average Particle

An experimental study was conducted to describe mass transfer impacts within nitrifying aggregates sourced from sequencing batch reactor (SBR) activated sludge systems. Flocculent and granular sludge with high nitrification activity was obtained in two laboratory SBR systems, supplied with a synthetic, ammonium-based feed. The flocculent biomass was fractionated using a sieving procedure, in order to obtain biomass fractions with different particle size distributions. The oxygen uptake rate (OUR) response to changes in dissolved oxygen concentration was measured under highly controlled conditions in a titrimetric and off-gas analysis (TOGA) sensor, and the results used to assess mass transfer effects. As the average particle size of the biomass increased, mass transfer limitations were found to increase significantly. Empirically fitted, apparent KS,O2 values were demonstrated to be highly dependent on particle size, and reflect the mass transfer limitations occurring in the aggregates within a given system. Such parameters thus have little to do with the actual biokinetic parameter from which they are derived. The results obtained from the TOGA sensor study were consistent with those obtained from a microelectrode study on the same nitrifying granules. Together, these studies add considerable weight to the conclusion that consideration of external and internal mass transfer limitations is vital to the accurate description of activated sludge treatment processes, particularly those with a high oxygen uptake rate.

Disturbance observer for estimation of oxygen uptake rate in an activated sludge reactor

2016 ◽  
Author(s):  
Francisco Jadilson dos Santos Silva ◽  
Euler C. T. de Macedo ◽  
Sebastian Y. C. Catunda ◽  
Carlos E. T. Dorea ◽  
Adrianus C. Van Haandel
Keyword(s):  
Oxygen Uptake ◽  
Activated Sludge ◽  
Uptake Rate ◽  
Disturbance Observer ◽  
Oxygen Uptake Rate ◽  
Activated Sludge Reactor

Appearance of excess lactate in anesthetized dogs during anemic and hypoxic hypoxia

1965 ◽  
Vol 209 (3) ◽  
pp. 604-610 ◽  
Author(s):  
Stephen M. Cain
Keyword(s):  
Cardiac Output ◽  
Oxygen Uptake ◽  
Oxygen Transport ◽  
Liver Dysfunction ◽  
Hypoxic Hypoxia ◽  
Blood Gas ◽  
Total Oxygen ◽  
Anesthetized Dogs ◽  
Lactate And Pyruvate ◽  
Mixed Venous

Ten anesthetized, splenectomized dogs were made progressively anemic by replacement of blood with warmed dextran to approximate hematocrits of 30, 20, 15, and 10%. A second group of 10 dogs was made progressively hypoxic by having them inspire 11.4, 9.5, 8.0, and 5.9% O2 in N2. Blood gas contents, pH, and gas tensions were measured in arterial and mixed venous bloods. Cardiac output was calculated from the arteriovenous O2 difference and the O2 uptake. Excess lactate was calculated from measured levels of lactate and pyruvate in blood water. Excess lactate appeared at higher mixed venous Po2 in anemic animals than in hypoxic, 40 mm Hg versus 20 mm Hg. When related to total oxygen transport, however, excess lactate appeared at about the same point (12 ml/kg per min) in both groups. Because liver has been shown to reduce its oxygen uptake with any lowering of perfusate oxygen content, it was suggested that the excess lactate measured during both anemic and hypoxic hypoxia in anesthetized dogs is largely the result of liver dysfunction with respect to lactate.

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