Seasonal Variation in the Respiratory Acclimatization of the Leech Erpobdella Testacea (sav.)

1958 ◽  
Vol 35 (2) ◽  
pp. 314-323
Author(s):  
K. H. MANN
Keyword(s):  
Carbon Monoxide ◽  
Oxygen Consumption ◽  
Seasonal Variation ◽  
Mercury Electrode ◽  
Saturated Water ◽  
Constant Rate ◽  
Dropping Mercury Electrode ◽  
Previous Level ◽  
Rate Of Oxygen Consumption ◽  
Normal Respiration

1. In summer the leech Erpobdella testacea becomes acclimatized to a low concentration of oxygen in the water, and can maintain a constant rate of oxygen consumption down to one-third air-saturation. This acclimatization does not occur in winter. 2. The mechanism of acclimatization is such that it can operate when the leeches are resting, and when the haemoglobin has been prevented from functioning by treatment with carbon monoxide. 3. In the course of normal respiration in air-saturated water at 20° C. about 45% of the oxygen is transported to the tissues by the haemoglobin. In one-third air-saturated water about 25% is transported in this way. 4. After a meal of Tubifex the oxygen consumption increases threefold, and declines to the previous level over a period of 4 days. 5. A polarographic respirometer embodying a wide-bore dropping mercury electrode has been developed for this work. It provides on a galvanometer a constant indication of the oxygen concentration in the water which has passed over the animals.

Oxygen sensitivity in the insect Prodenia eridania

1960 ◽  
Vol 198 (2) ◽  
pp. 441-444 ◽  
Author(s):  
Arnold M. Clark ◽  
V. J. Cristofalo
Keyword(s):  
Carbon Monoxide ◽  
Oxygen Consumption ◽  
Metabolic Rate ◽  
Adult Stage ◽  
Oxygen Sensitivity ◽  
Rate Of Oxygen Consumption ◽  
Injurious Effects

Both the larval and pupal stages of prodenia eridania are injured by oxygen at increased pressures. The injury is manifested by a reduction in the rate of oxygen consumption, muscular paralysis and failure to develop to the adult stage. In the pupae these effects appear together as a syndrome. Pupae are much more sensitive than larvae. At least 75 psi of oxygen is necessary for injury to larvae while only 45 psi is required to produce injury in the pupae. Injured pupae respire at a rate 2%–5% of the controls while the injured larvae consume oxygen at 60% of the control rate. In attempts to modify this sensitivity by pretreatment with agents which reduce the metabolic rate, it was found that pupae kept at –10°C for 30 minutes before treatment or kept in carbon monoxide or nitrogen for 30 minutes prior to treatment showed none of the injurious effects of oxygen.

scholarly journals Predicting the rate of oxygen consumption during the 3-minute constant-rate stair stepping and shuttle tests in people with COPD

2020 ◽  
Vol 12 (5) ◽  
pp. 2489-2498 ◽  
Author(s):  
Hayley Lewthwaite ◽  
Emily M. Koch ◽  
Magnus Ekström ◽  
Alan Hamilton ◽  
Jean Bourbeau ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Constant Rate ◽  
Rate Of Oxygen Consumption

THE RESPIRATION OF ASCARIS LUMBRICOIDES EGGS

1955 ◽  
Vol 33 (6) ◽  
pp. 1033-1046 ◽  
Author(s):  
Richard F. Passey ◽  
Donald Fairbairn
Keyword(s):  
Carbon Monoxide ◽  
Oxygen Consumption ◽  
Cytochrome C ◽  
Cytochrome Oxidase ◽  
Ascaris Lumbricoides ◽  
Enzyme System ◽  
High Sensitivity ◽  
Partial Pressures ◽  
Rate Of Oxygen Consumption ◽  
Low Sensitivity

The rate of oxygen consumption of developing ascaris eggs decreased rapidly to a minimum after 1.5 days, and thereafter increased to a maximum at 10 days, when the embryos were vermiform. During the 10–20 day period, when the embryo matures and molts once in the egg, the respiration decreased steadily, and continued to decrease more slowly until at 140 days the rate was scarcely measurable. Nevertheless, the eggs remained viable and hatched readily in the mouse gut. Cytochrome c and cytochrome oxidase could not be detected by direct assay or isolation. However, the high sensitivity of the respiration to carbon monoxide (in the dark), to cyanide, and to azide, and the low sensitivity to carbon monoxide (in the light) and to decreasing partial pressures of oxygen, indicated that oxidases such as the flavoproteins, phenolases, and peroxidases were unlikely respiratory catalysts, and that cytochrome oxidase, or a similar and hitherto undescribed enzyme, was the major component of the terminal respiratory enzyme system.

scholarly journals The Respiratory Function of the Haemoglobin of the Earthworm

1942 ◽  
Vol 18 (3) ◽  
pp. 266-277
Author(s):  
M. L. JOHNSON
Keyword(s):  
Carbon Monoxide ◽  
Oxygen Consumption ◽  
Oxygen Pressure ◽  
Respiratory Function ◽  
Respiratory Enzymes ◽  
Partial Pressures ◽  
Rate Of Oxygen Consumption

The oxygen consumption of earthworms (Lumbricus herculeus Savigny) has been measured at 10°C., in the dark, in atmospheres containing 20, 10, 5, 2.5 and 1% of oxygen (i.e. at partial pressures of oxygen of about 152, 76, 38, 19 and 8 mm. mercury), with and without the addition of enough carbon monoxide to saturate the haemoglobin of the blood. In the absence of carbon monoxide the rate of oxygen consumption was significantly the same at 152 and 76 mm.; below 76 mm. it fell sharply. The rate of oxygen consumption of carbon monoxide-treated worms was significantly lower than that of normal worms at oxygen pressures of 152, 76, 38 and 19 mm. but not at 8 mm. The respiration of slices of earthworm has been measured in atmospheres containing 20% of oxygen, and 20% of oxygen together with 20% of carbon monoxide. The rate of respiration in the presence of carbon monoxide was 110% of that in its absence. It is concluded that the lowering of the rate of respiration of whole worms caused by carbon monoxide was not due to inhibition of respiratory enzymes, but to its effect on haemoglobin. Haemoglobin therefore transports oxygen at atmospheric as well as at lower partial pressures of oxygen. Less oxygen was carried by haemoglobin at 19 mm. than at 38 mm. It is deduced that the loading pressure of earthworm haemoglobin is higher than 19 mm. The haemoglobin, of the blood was responsible for supplying about 23% of the respired oxygen when the oxygen pressure was at 152 mm., 35% at 76 mm., 40% at 38 mm.; and 22% at 19 mm. of oxygen.

THE RESPIRATION OF ASCARIS LUMBRICOIDES EGGS

1955 ◽  
Vol 33 (1) ◽  
pp. 1033-1046 ◽  
Author(s):  
Richard F. Passey ◽  
Donald Fairbairn
Keyword(s):  
Carbon Monoxide ◽  
Oxygen Consumption ◽  
Cytochrome C ◽  
Cytochrome Oxidase ◽  
Ascaris Lumbricoides ◽  
Enzyme System ◽  
High Sensitivity ◽  
Partial Pressures ◽  
Rate Of Oxygen Consumption ◽  
Low Sensitivity

The rate of oxygen consumption of developing ascaris eggs decreased rapidly to a minimum after 1.5 days, and thereafter increased to a maximum at 10 days, when the embryos were vermiform. During the 10–20 day period, when the embryo matures and molts once in the egg, the respiration decreased steadily, and continued to decrease more slowly until at 140 days the rate was scarcely measurable. Nevertheless, the eggs remained viable and hatched readily in the mouse gut. Cytochrome c and cytochrome oxidase could not be detected by direct assay or isolation. However, the high sensitivity of the respiration to carbon monoxide (in the dark), to cyanide, and to azide, and the low sensitivity to carbon monoxide (in the light) and to decreasing partial pressures of oxygen, indicated that oxidases such as the flavoproteins, phenolases, and peroxidases were unlikely respiratory catalysts, and that cytochrome oxidase, or a similar and hitherto undescribed enzyme, was the major component of the terminal respiratory enzyme system.

scholarly journals STUDIES ON CELL METABOLISM AND CELL DIVISION

1940 ◽  
Vol 23 (4) ◽  
pp. 401-411 ◽  
Author(s):  
G. H. A. Clowes ◽  
M. E. Krahl
Keyword(s):  
Carbon Monoxide ◽  
Oxygen Consumption ◽  
Cell Division ◽  
Cell Metabolism ◽  
Potassium Cyanide ◽  
Iodoacetic Acid ◽  
Mass Action ◽  
Comparable Rate ◽  
Arbacia Punctulata ◽  
Rate Of Oxygen Consumption

1. The effects of a number of respiratory inhibiting agents on the cell division of fertilized eggs of Arbacia punctulata have been determined. For eggs initially exposed to the reagents at 30 minutes after fertilization at 20°C., the levels of oxygen consumption prevailing in the minimum concentrations of reagents which produced complete cleavage block were (as percentages of the control): In 0.4 per cent O2-99.6 per cent N2, 32; in 0.7 per cent O2-99.3 per cent CO, 32; in 1.6 x 10–4M potassium cyanide, 34; in 1 x 10–3M phenylurethane, 70; in 4 x 10–3M 5-isoamyl-5-ethyl barbituric acid, 20; in 3 x 10–4M iodoacetic acid, 53. 2. The carbon monoxide inhibition of oxygen consumption and cell division was reversed by light. The percentage inhibition of oxygen consumption by carbon monoxide in the dark is described by the usual mass action equation with K, the inhibition constant, equal to approximately 60, as compared to values of 5 to 10 for yeast and muscle. In 20 per cent O2-80 per cent CO in the dark there was a slight stimulation of oxygen consumption, averaging 20 per cent. 3. Spectroscopic examination of fertilized and unfertilized Arbacia eggs reduced by hydrosulfite revealed no cytochrome bands. The thickness and density of the egg suspension was such as to indicate that, if cytochrome is present at all, the amount in Arbacia eggs is extremely small as compared to that in other tissues having a comparable rate of oxygen consumption. 4. Three reagents poisoning copper catalyses, potassium dithio-oxalate (10–2M), diphenylthiocarbazone (10–4M), and isonitrosoacetophenone (2 x 10–3M) produced no inhibition of division of fertilized Arbacia eggs. 5. These results indicate that the respiratory processes required to support division in the Arbacia egg may perhaps differ in certain essential steps from the principal respiratory processes in yeast and muscle.

Reduction and tensammetric pulse-polarographic currents of polynucleotides

1987 ◽  
Vol 52 (11) ◽  
pp. 2810-2818 ◽  
Author(s):  
Emil Paleček ◽  
František Jelen ◽  
Vladimír Vetterl
Keyword(s):  
Diagnostic Criteria ◽  
Pulse Width ◽  
Mercury Electrode ◽  
Pulse Amplitude ◽  
Single Strand ◽  
Pulse Polarography ◽  
Dropping Mercury Electrode ◽  
Adenylic Acid ◽  
Drop Time

The behaviour of electrochemically reducible single-strand polynucleotides (poly(adenylic acid)) and poly(cytidylic acid)) was studied by the differential (derivative) pulse polarography (DPP) and by other methods. Measurements were performed with the help of the dropping mercury electrode under various conditions specified by the pulse width, pulse amplitude, drop time etc. For the faradaic and tensammetric DPP peaks the diagnostic criteria were proposed which make it possible to classify even very small DPP peaks of double helical polynucleotides.

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