Thyroxine and the Oxygen Consumption of the Spermatozoa of Echinus Miliaris

1930 ◽  
Vol 7 (1) ◽  
pp. 41-48
Author(s):  
G. S. CARTER
Keyword(s):  
Oxygen Consumption ◽  
Chemical Structure ◽  
Initial Rate ◽  
Sea Water ◽  
Physiological Effect ◽  
Rate Of Oxygen Consumption

1. In the presence of thyroxine in concentrations of 1/45,000 to 1/75,000 the initial rate of oxygen consumption of the spermatozoa of Echinus miliaris is the same as in sea-water without the drug, but this rate of oxygen consumption is prolonged for a longer time in the presence of the drug. The rate of oxygen consumption in the presence of the drug falls after this period, and at the end of 2-4 hours is approximately equal to that in clean sea-water. 2. In a concentration of 1/30,000 the drug is toxic, and of 1/100,000 the effect is incomplete. 3. These effects are parallel to, and apparently of the same nature as, the effects of secretions of the eggs of the same species upon the oxygen consumption; but the effects of the egg secretions are much greater in extent. 4. The suggestion is made that the egg secretions contain, in addition to their other known constituents, either a body of which the physiological effect is similar to that of thyroxine, and which is perhaps similar to it in chemical structure, or some constituent from which such a body is built, when it is absorbed by the spermatozoon. 5. In its action upon the spermatozoon the effect of thyroxine is to remove or reduce the cause of the decreasing activity of the spermatozoon in sea-water (as revealed by its oxygen consumption). This effect is immediate and may take place at any period during the life of the spermatozoon at which its oxygen consumption in the presence of thyroxine is greater than that in sea-water.

Osmotic balance and respiration in the hermit crab, Pagurus bernhardus, exposed to fluctuating salinities

1978 ◽  
Vol 58 (4) ◽  
pp. 869-876 ◽  
Author(s):  
Sandra E. Shumway
Keyword(s):  
Oxygen Consumption ◽  
Sea Water ◽  
External Medium ◽  
Temporary Increase ◽  
Tissue Water ◽  
Low Salinity ◽  
Significant Difference ◽  
Rate Of Oxygen Consumption ◽  
Osmotic Balance ◽  
Pagurus Bernhardus

Specimens of Pagurus bernhardus (with and without shells) were exposed to both gradual (sinusoidal) and abrupt (square-wave) salinity fluctuations and changes in haemolymph osmolality, tissue water content and oxygen consumption monitored. Oxygen consumption was also monitored under steady-state conditions; under these conditions there was no significant difference between the rate of oxygen consumption by animals with shells and animals without shells. Oxygen consumption was found to vary with body weight according to the equation O2 consumption = 0·292 W0·668. During exposure to fluctuating salinities the crabs with shells were seen to increase loco-motory activity when the external medium declined to approximately 75% sea water. Haemolymph osmolality values followed the same pattern of change as the external medium; the haemolymph of crabs without shells became significantly more dilute during exposure to low salinity than did that of crabs with shells. P. bernhardus showed significant increases and decreases in hydration level as salinities fell and rose respectively. Crabs with shells showed a marked temporary increase in oxygen consumption when the external medium declined to approximately 75% sea water; crabs without shells showed no such response. The importance of the shell as a means of protection against dilute media is discussed.

Burrowing behaviour and anaerobiosis in the bivalve Arctica islandica (L.)

1976 ◽  
Vol 56 (1) ◽  
pp. 95-109 ◽  
Author(s):  
A. C. Taylor
Keyword(s):  
Oxygen Consumption ◽  
Initial Rate ◽  
Recovery Period ◽  
Oxygen Demand ◽  
Ventilation Rate ◽  
Oxygen Utilization ◽  
Arctica Islandica ◽  
Aerobic Conditions ◽  
Rate Of Oxygen Consumption ◽  
Burrowing Activity

In laboratory tanks as well as in the sea Arctica islandica shows a pattern of intermittent burrowing activity. Periods spent at the surface of the deposit alternate with periods buried several centimetres beneath the surface of the sand, during which the animals respire anaerobically. There is no obvious rhythmicity to this behaviour; the duration of periods spent beneath the surface is very variable even in the same animal, but normally lasts between 1 and 7 days.On the return to aerobic conditions both the heart rate and oxygen consumption areincreased but decline gradually during the following 20–25 h. This increased oxygen uptake is caused primarily by an increase in oxygen utilization but there is little change in ventilation rate. Both the initial rate of oxygen consumption and the duration of the recovery period show a correlation with the duration of the period of anaerobiosis. The concentration of alaninc in the blood of Arctica is high immediately after the return to aerobic conditions but declines during the recovery period. The similarity in the time taken for the concentration of alanine in the blood and the oxygen consumption of Arctica to return to normal levels suggests that at least part of this increased oxygen demand is associated with the metabolism of end-products of anaerobiosis.

The Respiratory Physiology of the Marine Nematodes Enoplus Brevis (Bastian) and E. Communis (Bastian)

1973 ◽  
Vol 59 (1) ◽  
pp. 267-274
Author(s):  
H. J. ATKINSON
Keyword(s):  
Oxygen Consumption ◽  
Sea Water ◽  
Atmospheric Oxygen ◽  
Respiratory Physiology ◽  
Marine Nematodes ◽  
Oxygen Regime ◽  
Lower Oxygen ◽  
Rate Of Oxygen Consumption ◽  
Oxygen Tensions ◽  
Oxygen Requirements

1. The rate of oxygen consumption of individual male Enoplus brevis and E. communis was measured at 15 °C, after altering the oxygen regime experienced since the animals were collected. 2. When both E. brevis and E. communis were transferred to 35 Torr from atmospheric oxygen tensions, their oxygen consumption was only two-thirds of that of individuals maintained at this lower oxygen tension. 3. The rate of oxygen consumption of the two species at 135 Torr was unaltered by exposure for 2 h to oxygen-free sea water. 4. The results are discussed in relation to the overall influence of fluctuating oxygen regimes on the oxygen requirements of nematodes.

scholarly journals Evaluation of bioremediation of oil-polluted soil using the respirometric oxitop® method.

2019 ◽  
pp. 47-54
Author(s):  
Aare Selberg ◽  
Toomas Tenno
Keyword(s):  
Oxygen Consumption ◽  
Sodium Dodecyl Sulfate ◽  
Contaminated Soil ◽  
Initial Rate ◽  
Sodium Dodecyl ◽  
Polluted Soil ◽  
Natural Processes ◽  
Rate Of Oxygen Consumption ◽  
Lag Period ◽  
Activation Of Oxygen

Bioremediation includes natural processes to degrade harmful compounds in theenvironment. The goal in bioremediation is to stimulate microorganisms with differentadditives that will activate them to destroy the contaminants. Respirometry methods havebeen used to assess the microbial activity of soil but a few respirational studies have beenperformed with surfactants.The objective of this study was to examine the effects of surfactants and adsorbents onoil-contaminanted soil respirational activity. The measurement of oxygen consumption isused to evaluate the enhancement of the bioremediation of polluted soil by surfactantsand adsorbents. Selected surfactants were sodium dodecyl sulfate (SDS), Saponine andemulsifying agent SR-100. In the present study the respirometric OxiTop® system wasused to measure the oxygen consumption of the soil by adding the different surfactants.The rates of oxygen consumption were calculated from respiration data.The measurements of respiration showed that the maximum initial rate of oxygenconsumption of soil was 4.39 mg 02 kg -1 h -1 at the water content of9% (w/w ). SR-100addition showed the highest initial rate of oxygen consumption - 18.61 mg 02 kg ·1 h -1•The medium rate of oxygen consumption of the oil contaminated soil for five days washalf of the initial rate. The mixtures of soil and the adsorbents had lower respirationalactivity, even when solutions of the surfactants were added. The highest initial rates ofoxygen consumption of soil were 4.24 mg Oi kg -1 h -1 ( Saponine solution was added) and13.00 mg 02 kg"1 h"1 (SR-100 solution was added) for the hydrophobic and hydrophilicadrorbents, respectively. For the mixture of soil and adsorbent the longer lag-period forthe activation of oxygen consumption occurred by the adding of surfactants.

scholarly journals Oxygen Consumption as a Function of Size and Salinity in Metapenaeus monoceros Fab. From Marine and Brackish-Water Environments

1958 ◽  
Vol 35 (2) ◽  
pp. 307-313
Author(s):  
KANDULA PAMPAPATHI RAO
Keyword(s):  
Oxygen Consumption ◽  
Brackish Water ◽  
Sea Water ◽  
Regression Coefficient ◽  
Tap Water ◽  
Osmotic Regulation ◽  
Osmotic Adaptation ◽  
Metapenaeus Monoceros ◽  
Rate Of Oxygen Consumption ◽  
Two Populations

1. The oxygen consumption in relation to the salinity of the medium has been studied in a marine and a brackish-water population of the prawn, Metapenaeus monoceros Fab. 2. It has been shown that the regression coefficient of oxygen consumption against weight is not the same for media of different salinity and for the two populations. 3. In both the groups of prawns an increase in the oxygen consumption was observed, with a decrease in the salinity of the medium below that of the habitat. But the marine prawns showed higher rates in 50 and 25% sea water compared to the brackish-water prawns. On the other hand, the brackish-water prawns exhibited a higher rate of oxygen consumption in 100% sea water and in tap water. 4. It is suggested that these differences might be due to (i) an osmotic adaptation, and (ii) the operation of a metabolic homoeostatic mechanism in relation to osmotic regulation.

scholarly journals The Respiratory Rate of Gammarus chevreuxi in Relation to Differences in Salinity

1935 ◽  
Vol 12 (3) ◽  
pp. 217-221
Author(s):  
OTTO LÖWENSTEIN
Keyword(s):  
Oxygen Consumption ◽  
Oxygen Uptake ◽  
Respiratory Rate ◽  
Brackish Water ◽  
Sea Water ◽  
Natural Habitat ◽  
Freshwater Species ◽  
Percentage Decrease ◽  
Rate Of Oxygen Consumption

1. The rate of oxygen uptake was studied in the brackish water amphipod Gammarus chevreuxi in water of different salinities (25 per cent, sea water and sea water). The respiratory rate was found to be approximately 20 per cent, lower in sea water than in 25 per cent, sea water which is a concentration occurring in the natural habitat. Anaesthetised animals showed the same percentage decrease as unanaesthetised animals. 2. The change in oxygen consumption takes place immediately after the transfer and remains constant thereafter. It is completely reversible. 3. A comparison with the unanaesthetised respiratory rates of the related freshwater species G. pulex and marine G. marinus shows that the rate of oxygen consumption of the brackish water form G. chevreuxi in 25 per cent, sea water lies between the two others.

Effect of a Reciprocal Photoperiod Regime on Standard Rate of Oxygen Consumption of Postsmolt Atlantic Salmon (Salmo salar)

1973 ◽  
Vol 30 (12) ◽  
pp. 1898-1900 ◽  
Author(s):  
Kathryn G. Withey ◽  
Richard L. Saunders
Keyword(s):  
Oxygen Consumption ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Sea Water ◽  
Late Summer ◽  
Atlantic Salmon Salmo Salar ◽  
Photoperiod Regime ◽  
Natural Photoperiod ◽  
Rate Of Oxygen Consumption ◽  
Standard Rate

Postsmolt Atlantic salmon (Salmo salar) subjected to a reciprocal photoperiod regime (decreasing daylength from early March and increasing daylength from late June) had significantly lower standard rates of oxygen consumption than those subjected to a simulated natural photoperiod regime when both were tested in total darkness in sea water in late summer. A reduced metabolic level, as indicated by the low standard rate of oxygen consumption, in the test fish is consistent with earlier observations of reduced feeding and growth rates and food conversion efficiencies in similarly treated fish following transfer to sea water.

scholarly journals Recovery heat in muscular contraction without lactic acid formation

1931 ◽  
Vol 108 (757) ◽  
pp. 279-301 ◽  
Keyword(s):  
Acetic Acid ◽  
Oxygen Consumption ◽  
Lactic Acid ◽  
Muscular Contraction ◽  
Acid Formation ◽  
Anaerobic Conditions ◽  
Spontaneous Breakdown ◽  
Rate Of Oxygen Consumption ◽  
Resting Muscle

In a comparison of muscles poisoned with mono-iodo-acetic acid (IAA) in the presence and in the absence of oxygen respectively, Lundsgaard (1930) found:- (1) That the spontaneous breakdown of phosphagen in poisoned resting muscle is much more rapid under anaerobic conditions. (2) That the onset of the characteristic contracture produced by IAA is accompanied always by an increase in the rate of oxygen consumption.

Proximal tubule dysfunction in cystine-loaded tubules: effect of phosphate and metabolic substrates

1996 ◽  
Vol 271 (3) ◽  
pp. F717-F722
Author(s):  
G. Bajaj ◽  
M. Baum
Keyword(s):  
Oxygen Consumption ◽  
Proximal Tubule ◽  
Tricarboxylic Acid Cycle ◽  
Dimethyl Ester ◽  
Proximal Tubules ◽  
Intracellular Atp ◽  
Metabolic Substrates ◽  
Rate Of Oxygen Consumption ◽  
Intracellular Phosphate

Intracellular cystine loading by use of cystine dimethyl ester (CDME) results in a generalized inhibition in proximal tubule transport due, in part, to a decrease in intracellular ATP. The present study examined the importance of phosphate and metabolic substrates in the proximal tubule dysfunction produced by cystine loading. Proximal tubule intracellular phosphorus was 1.8 +/- 0.1 in control tubules and 1.1 +/- 0.1 nmol/mg protein in proximal tubules incubated in vitro with CDME P < 0.001). Infusion of sodium phosphate in rabbits and subsequent incubation of proximal tubules with a high-phosphate medium attenuated the decrease in proximal tubule respiration and prevented the decrease in intracellular ATP with cystine loading. Tricarboxylic acid cycle intermediates have been shown to preserve oxidative metabolism in phosphate-depleted proximal tubules. In proximal tubules incubated with either 1 mM valerate or butyrate, there was a 42 and 34% reduction (both P < 0.05) in the rate of oxygen consumption with cystine loading. However, tubules incubated with 1 mM succinate or citrate had only a 13 and 14% P = NS) reduction in the rate of oxygen consumption, respectively. These data are consistent with a limitation of intracellular phosphate in the pathogenesis of the proximal tubule dysfunction with cystine loading.

Viability and respiratory activity ofPseudomonas syringaecells starved in buffer

1995 ◽  
Vol 41 (4-5) ◽  
pp. 372-377 ◽  
Author(s):  
João P. S. Cabral
Keyword(s):  
Oxygen Consumption ◽  
Electron Transport ◽  
Pseudomonas Syringae ◽  
Respiratory Activity ◽  
Bacterial Cells ◽  
Intact Cells ◽  
Rate Of Oxygen Consumption ◽  
Metabolic Activities ◽  
Different Levels ◽  
Number Of Cells

Pseudomonas syringae cells starved in buffer released orcinol-reactive molecules and materials that absorbed ultraviolet light. The number of cells culturable in nutrient medium decreased more rapidly than the number of intact particles determined by microscopy. The results suggested that starvation resulted in the lysis of an increasing number of cells, and that a fraction of the intact particles were not culturable. Starvation also resulted in a decrease in the rate of oxygen consumption with acetate, glycerol, and succinate, but at different levels. Whereas the respiration of acetate and glycerol decreased concomitantly with culturability, the respiration of succinate decreased to levels similar to the concentration of intact cells, suggesting that all intact particles respired the succinate, but only the culturable cells respired the acetate and glycerol. The results suggest that measuring the activity of the electron-transport system can overestimate the viability of starved bacterial cells, and that complex metabolic activities such as the respiration of acetate and glycerol are probably better suited for the evaluation of this parameter.Key words: Pseudomonas syringae, starvation, culturability, viability, respiration.

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