Some Aspects of Gas Exchange in Tuna

1972 ◽  
Vol 56 (3) ◽  
pp. 809-823
Author(s):  
E. D. STEVENS
Keyword(s):  
Hydrostatic Pressure ◽  
Gas Exchange ◽  
Oxygen Uptake ◽  
Average Rate ◽  
Oxygen Removal ◽  
Skipjack Tuna ◽  
Partial Pressure Of Oxygen ◽  
Free Swimming ◽  
Flow Rates ◽  
Theoretical Predictions

1. Some aspects of gas exchange in restrained skipjack tuna were analysed. 2. The average rate at which water flowed over the gills was 2.81/min. kg. 3. The concentration of oxygen in water entering and leaving the gills was measured and used to calculate oxygen uptake (692 mg/h.kg) and utilization (0.71). 4. The drop in hydrostatic pressure as water flowed over the gills was 1.9 cm water and agrees favourably with theoretical predictions. 5. The partial pressure of oxygen was measured in blood afferent and efferent to the gills and used to calculate effectiveness of oxygen removal from the water (90%) and the transfer factor for oxygen (0.12 ml/min.kg.mmHg). 6. The average utilization measured in free-swimming tuna was 0.56. 7. The extraordinary ability of tuna to efficiently extract oxygen from the water at high gill water flow rates is discussed.

Pulmonary Gas Exchange and Oxygen Uptake During Exercise in Patients with Type 1 Diabetes Mellitus

1992 ◽  
Vol 9 (3) ◽  
pp. 252-257 ◽  
Author(s):  
Th. Wanke ◽  
D. Formanek ◽  
M. Auinger ◽  
H. Zwick ◽  
K. Irsigler
Keyword(s):  
Diabetes Mellitus ◽  
Type 1 Diabetes ◽  
Gas Exchange ◽  
Oxygen Uptake ◽  
Type 1 Diabetes Mellitus ◽  
Pulmonary Gas Exchange

Maximal oxygen uptake during free, tethered, and flume swimming

1980 ◽  
Vol 48 (2) ◽  
pp. 232-235 ◽  
Author(s):  
A. Bonen ◽  
B. A. Wilson ◽  
M. Yarkony ◽  
A. N. Belcastro
Keyword(s):  
Oxygen Uptake ◽  
Maximal Oxygen Uptake ◽  
Free Swimming ◽  
Considerable Error ◽  
Arm Ergometry ◽  
Arm Ergometer ◽  
Highly Correlated ◽  
Ergometer Test

The purpose of this study was 1) to compare the maximal oxygen uptake (VO2max) obtained in swimmers during tethered swimming, free swimming, and flume swimming, and 2) to determine whether an arm-ergometer test would provide comparable results. In the first experiments the VO2max for tethered swimming (2.67 +/- 0.26 l/min) and flume swimming (2.62 +/- 0.26 l/min) were not different (P greater than 0.05) and were highly correlated (r = 0.99). However, with arm ergometry a significantly lower VO2max (2.36 +/- 0.24 l/min) occurred from those found in the two swimming tests (P less than 0.05). Other experiments demonstrated that the tethered swimming VO2max (3.53 +/- 0.27 l/min) and the free swimming VO2max (3.55 +/- 0.28 l/min) also provide results that were similar (P greater than 0.05) and highly correlated with each other (r = 0.99). Differences between tethered and flume swimming, and tethered and free swimming were small, being 1.2 +/- 1.6% and 0.6 +/- 0.9%, respectively. Differences between tethered swimming and arm ergometry VO2max were large, 14.7 +/- 2.4%, despite the high correlation (r = 0.97) between these measurements. Predictions of a swimming VO2max from the arm-ergometer data yielded a considerable error (+/-7.1% and +/-7.4%). The present results indicate that flume swimming, free swimming, and tethered swimming yield essentially identical VO2max results.

scholarly journals Coca chewing for exercise: hormonal and metabolic responses of nonhabitual chewers

1996 ◽  
Vol 81 (5) ◽  
pp. 1901-1907 ◽  
Author(s):  
Roland Favier ◽  
Esperanza Caceres ◽  
Laurent Guillon ◽  
Brigitte Sempore ◽  
Michel Sauvain ◽  
...  
Keyword(s):  
Heart Rate ◽  
Gas Exchange ◽  
Oxygen Uptake ◽  
Metabolic Responses ◽  
Physiological Data ◽  
Respiratory Gas Exchange ◽  
Gum Chewing ◽  
Arterial Blood ◽  
Before And After ◽  
Exercise Induced

Favier, Roland, Esperanza Caceres, Laurent Guillon, Brigitte Sempore, Michel Sauvain, Harry Koubi, and Hilde Spielvogel. Coca chewing for exercise: hormonal and metabolic responses of nonhabitual chewers. J. Appl. Physiol. 81(5): 1901–1907, 1996.—To determine the effects of acute coca use on the hormonal and metabolic responses to exercise, 12 healthy nonhabitual coca users were submitted twice to steady-state exercise (∼75% maximal O2 uptake). On one occasion, they were asked to chew 15 g of coca leaves 1 h before exercise, whereas on the other occasion, exercise was performed after 1 h of chewing a sugar-free chewing gum. Plasma epinephrine, norepinephrine, insulin, glucagon, and metabolites (glucose, lactate, glycerol, and free fatty acids) were determined at rest before and after coca chewing and during the 5th, 15th, 30th, and 60th min of exercise. Simultaneously to these determinations, cardiorespiratory variables (heart rate, mean arterial blood pressure, oxygen uptake, and respiratory gas exchange ratio) were also measured. At rest, coca chewing had no effect on plasma hormonal and metabolic levels except for a significantly reduced insulin concentration. During exercise, the oxygen uptake, heart rate, and respiratory gas exchange ratio were significantly increased in the coca-chewing trial compared with the control (gum-chewing) test. The exercise-induced drop in plasma glucose and insulin was prevented by prior coca chewing. These results contrast with previous data obtained in chronic coca users who display during prolonged submaximal exercise an exaggerated plasma sympathetic response, an enhanced availability and utilization of fat (R. Favier, E. Caceres, H. Koubi, B. Sempore, M. Sauvain, and H. Spielvogel. J. Appl. Physiol. 80: 650–655, 1996). We conclude that, whereas coca chewing might affect glucose homeostasis during exercise, none of the physiological data provided by this study would suggest that acute coca chewing in nonhabitual users could enhance tolerance to exercise.

Hydrogen Generation in an Annular Micro-Reactor: an Experimental Investigation of Water Splitting Reaction Using Aluminum in Presence of Potassium Hydroxide

2018 ◽  
Vol 17 (2) ◽  
Author(s):  
Shyam P. Tekade ◽  
Diwakar Z. Shende ◽  
Kailas L. Wasewar
Keyword(s):  
Water Splitting ◽  
Potassium Hydroxide ◽  
Hydrogen Generation ◽  
Energy Content ◽  
Average Rate ◽  
High Energy ◽  
Low Flow ◽  
Flow Rates ◽  
Metal Aluminum ◽  
Micro Reactor

Abstract Hydrogen is one of the important non-conventional energy sources because of its high energy content and non-polluting nature of combustions. The water splitting reaction is one of the significant methods for hydrogen generation from non-fossil feeds. In the present paper, the hydrogen generation has been experimentally investigated with water splitting reaction using metal aluminum in presence of potassium hydroxide as an activator under flow conditions. The rate of hydrogen generation was reported in the annular micro- reactor of 1 mm annulus using various flow rates of aqueous 0.5 N KOH ranging from 1 ml/min to 10 ml/min. The complete conversion of aluminum was observed at all the flow rates of aqueous KOH. The hydrogen generation rate was observed to depend on the flow rate of liquid reactant flowing through the reactor. At 1 ml/min of 0.5 N KOH, hydrogen generates at an average rate of 3.36 ml/min which increases to 10.70 ml/min at 10 ml/min of aqueous KOH. The Shrinking Core Model was modified for predicting the controlling mechanism. The rate of hydrogen generation was observed to follow different controlling mechanisms on various time intervals at low flow rates of aqueous KOH. It was observed that chemical reaction controls the overall rate of hydrogen generation at higher flow rates of aqueous KOH.

Ventilation and gas exchange in lizards during treadmill exercise.

1997 ◽  
Vol 200 (20) ◽  
pp. 2629-2639
Author(s):  
T Wang ◽  
D R Carrier ◽  
J W Hicks
Keyword(s):  
Exchange Rate ◽  
Gas Exchange ◽  
Oxygen Uptake ◽  
Minute Ventilation ◽  
Oxygen Demand ◽  
Lung Ventilation ◽  
Iguana Iguana ◽  
Maximal Aerobic Speed ◽  
Gas Exchange Rate ◽  
Treadmill Locomotion

The extent to which lizards ventilate their lungs during locomotion is controversial. Direct measurements of airflow across the nostrils suggest a progressive reduction in tidal volume and minute ventilation with increased running speed, while other studies have demonstrated that arterial PO2 remains constant during exercise. To resolve these conflicting findings, we measured minute ventilation and gas exchange rate in five specimens of Varanus exanthematicus and five specimens of Iguana iguana during treadmill locomotion at speeds between 0.14 and 1.11ms-1 at 35 degrees C. These speeds are much lower than maximal running speeds, but are greater than the maximal aerobic speed. In both species, the ventilatory pattern during locomotion was highly irregular, indicating an interference between locomotion and lung ventilation. In Varanus exanthematicus, treadmill locomotion elicited a six- to eightfold increase in minute ventilation from a pre-exercise level of 102mlkg-1min-1, whereas the rate of oxygen uptake increased approximately threefold (from 3.9 to 12.6mlkg-1min-1). After exercise, both minute ventilation and gas exchange rate decreased immediately. Because minute ventilation increased more than did oxygen consumption, an increase in lung PO2 during exercise is predicted and, thus, Varanus exanthematicus appears effectively to ventilate its lungs to match the increased metabolic rate during locomotion at moderate speed. In Iguana iguana, both minute ventilation and gas exchange rate increased above resting values during locomotion at 0.28ms-1, but both decreased with further increases in locomotor speed. Furthermore, following exercise, both minute ventilation and oxygen uptake rate increased significantly. Iguana iguana, therefore, appears to be unable to match the increased oxygen demand with adequate ventilation at moderate and higher speeds.

Etherőair anesthesia for small experimental animals

1964 ◽  
Vol 19 (4) ◽  
pp. 827-828
Author(s):  
F. W. Walker
Keyword(s):  
Partial Pressure ◽  
Compressed Air ◽  
Vapor Concentration ◽  
Partial Pressure Of Oxygen ◽  
Inhalation Anesthesia ◽  
Flow Rates ◽  
Experimental Animals ◽  
Anesthetic Apparatus ◽  
Polyethylene Tubing

An apparatus using compressed air for the semiquantitative administration of ether-air mixtures to experimental animals has been constructed in quantity from bottles, polyethylene tubing, and roller clamps available from hospital discard. Ether concentrations at various flow rates can be derived from the depression of the partial pressure of oxygen in the ether-air mixture. Inexpensive and useful in research, the apparatus also acquaints the student with the quantitative aspects of inhalation anesthesia. anesthetic apparatus for experimental animals; ether vapor concentration calculated from pO2 in ether-air mixtures Submitted on June 10, 1963

Mass Spectrometry Analysis of Oxygen Gas Exchange in High- and LOW-CO2 Cells of Chlorella vulgaris

1988 ◽  
Vol 43 (9-10) ◽  
pp. 709-716 ◽  
Author(s):  
Y. Shiraiwa ◽  
K. P. Bader ◽  
G. H. Schmid
Keyword(s):  
Gas Exchange ◽  
Oxygen Uptake ◽  
Chlorella Vulgaris ◽  
Mitochondrial Respiration ◽  
Mass Spectrometry Analysis ◽  
Strong Light ◽  
Inlet System ◽  
Light Intensities ◽  
Oxygen Gas ◽  
A Minor

Abstract Oxygen gas exchange was monitored in the unicellular green alga Chlorella vulgaris 211 - 11 h by means of a mass spectrometer equipped with a special membrane gas-inlet-system and a photosynthetic reaction vessel. CO2-dependent 18O2-uptake as well as 16O2-evolution were analyzed in both High- and Low-CO2 cells. In High-CO2 cells, the 18O2-ruptake in the light (UL) decreased by 65% upon addition of 3 mᴍ NaHCO3 , while 16O2-evolution (E) was increased approx. 1.8 times by the same treatment. 18O2-uptake in the dark (UD) was not affected by the addition of external inorganic carbon (Ci). The addition of 3.3 mᴍ NaHCO3 also affected UL and E in Low CO2-cells, however, to a minor extent. UL under CO2-saturating conditions was light intensity-independent up to 2 klux and 1.2 klux in High- and Low-CO2 cells, respectively. Above these light intensities UL increased approx. 4-fold in High- and approx. 6-fold in Low-CO2 cells. Under CO2-limiting conditions, however, UL increased in High-CO2 cells even under very low light intensities, showing that photorespiratory oxygen uptake occurred even in the near vicinity of the light compensation point. Under C02-saturating and strong light conditions UL represented almost half of E in Low-CO2 cells and about 30 % of E in High-CO2 cells. In Low-CO2 cells addition of ethoxyzolamide (EZA), an inhibitor of carbonic anhydrase, enhanced UL and suppressed E and NET under CO2-limiting conditions, whereas the compound had only a minor effect on High-CO2 cells. DCMU (3 μᴍ) strongly inhibited E and UL under CO2-saturating conditions, with the remaining UL being smaller than UD . KCN (1 mᴍ) and SHAM (1.5 mᴍ) added to DCMU-treated Low-CO2 cells suppressed UL by approx. 50 % . The resulting value corresponded to half of UD . KCN also inhibited E under CO2-saturating conditions, with UL being strongly enhanced showing a maximal uptake at 0.4 mᴍ KCN . Under these conditions NET was nearly zero. The effect seems to be due to an inhibition of RubisCO and an enhancement of Mehler reactions. At 0.7 mᴍ KCN , DCMU entirely inhibited UL , but oxygen uptake appeared increased after turning the light off. This uptake corresponded to approx. 60 % of UD . Whereas KCN and SHAM inhibited approx. 70 % of UD , only 16% of UL was suppressed. These results suggest that the contribution of mitochondrial respiration to UL was negligeable, since UL seemed to be suppressed in the light under CO2-saturated conditions. Iodoacetamide, which is an inhibitor of the Calvin cycle and thereby diverts carbon into the respiratory pathway, inhibited E and NET under CO2-saturating conditions, but did not affect UL . This result also shows that UL is not due to mitochondrial respiration. A hydroxylamine derivative [20, 21] which changes the ratio of the RuBP carboxylation to oxygenation activity in tobacco leaves did not affect this ratio in Chlorella.

Prolonged methacholine-induced bronchoconstriction in dogs

1979 ◽  
Vol 47 (2) ◽  
pp. 418-424 ◽  
Author(s):  
J. W. Ramsdell ◽  
P. F. Georghiou
Keyword(s):  
Lung Function ◽  
Gas Exchange ◽  
Lung Compliance ◽  
Cholinergic Stimulation ◽  
Partial Pressure Of Oxygen ◽  
Pulmonary Resistance ◽  
Mechanically Ventilated ◽  
Arterial Partial Pressure ◽  
Dynamic Lung Compliance ◽  
And Control

We studied the effect of prolonged airways obstruction induced by extended cholinergic stimulation in five anesthetized, mechanically ventilated dogs. A continuous intravenous metacholine infusion was utilized to maintain pulmonary resistance (RL) at 200--1500% preinfusion levels for 13--23 h. At maximum RL (18.86 +/- 7.74 vs. 2.09 +/- 0.18 (mean +/- SD) cmH2O/ (L/S) PREINfusion; P less than 0.01), dynamic lung compliance (Cdyn) fell from 67.5 +/- 14.6 to 32.7 +/- 11.6 ml/cmH2O (P less than 0.005) and arterial partial pressure of oxygen (PaO2) fell modestly from 95.8 +/- 6.1 Torr preinfusion to 83.2 +/- 12.7 Torr (P less than 0.05). Tachyphylaxis to methacholine developed, requiring increases in infusion rates to maintain elevated RL. Abnormalities in lung function resolved promptly upon termination of the infusion. Two similarly instrumented control animals ventilated for 19 and 25 h without metacholine infusion had no change in RL, Cdyn, or PaO2. Histological examination of the lungs revealed no differences between infused and control animals. In spite of marked increases in RL, prolonged cholinergic stimulation produced only mild changes in gas exchange and no sustained changes in lung function or structure.

SOME EFFECTS OF HYPERBARIC OXYGENATION ON BACTERIA AT INCREASED HYDROSTATIC PRESSURES

1967 ◽  
Vol 13 (10) ◽  
pp. 1311-1319 ◽  
Author(s):  
Claude E. ZoBell ◽  
Leslie L. Hittle
Keyword(s):  
Hydrostatic Pressure ◽  
Dissolved Oxygen ◽  
Partial Pressure ◽  
Oxygen Content ◽  
Hyperbaric Oxygenation ◽  
Bacterial Species ◽  
Partial Pressure Of Oxygen ◽  
Nutrient Media ◽  
Initial Oxygen Content ◽  
Initial Oxygen

The adverse effects of hyperbaric oxygenation on the reproduction and survival of bacteria are augmented by increased hydrostatic pressure. Different bacterial species differ considerably in their tolerance of increased hydrostatic pressure as well as for increased partial pressure of oxygen. Although their generation times may be lengthened and their reproduction rates retarded by increased pressures, most species of well-known bacteria are able to grow at hydrostatic pressures as high as 200–400 atm. In closed systems at 1 atm, certain aerobic bacteria grow well, or sometimes better, in nutrient media in which the partial pressure of oxygen is 5 to 10 times higher than that in the normal atmosphere (-Po2ca. 0.2 atm, equivalent to a dissolved oxygen content of ca. 7 μg/ml), but such increased concentrations of oxygen (35–70 μg/ml) are injurious at substantially increased hydrostatic pressures, for example, 5–25 atm. Escherichia coli, Bacillus subtilis, Bacillus megaterium, Pseudomonas enalia, Pseudomonas perfectomarinus, and Serratia marinorubra were sterilized within a day or two by compression to 100 atm in media having a dissolved oxygen content of 35 μg/ml. All six species thrived at 100 atm in nutrient media having an initial oxygen content of 7 μg/ml and they grew well in media with an oxygen content of 35 μg/ml at 1 atm.

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