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.

scholarly journals STUDIES ON CELL METABOLISM AND CELL DIVISION

1936 ◽  
Vol 20 (2) ◽  
pp. 173-184 ◽  
Author(s):  
M. E. Krahl ◽  
G. H. A. Clowes
Keyword(s):  
Oxygen Consumption ◽  
Cell Division ◽  
Cell Metabolism ◽  
Substituted Phenols ◽  
Experimental Conditions ◽  
Arbacia Punctulata ◽  
Oxidation Reduction ◽  
Rate Of Oxygen Consumption ◽  
Considerable Support ◽  
Stimulation Of

The dihalo and trihalophenols, and phenols containing both halo and nitro substituents in the same molecule, produce, in fertilized eggs of Arbacia punctulata, a rise in rate of oxygen consumption and a reversible block to cell division. To define the conditions which affect the degree of this activity, the following factors have been varied: the arrangement of substituents in the molecule, the concentration of reagent, and the time after fertilization at which the reagent is added. The stimulation of oxygen consumption and reversible block to cell division produced by the dihalophenols are qualitatively the same as those previously produced in fertilized Arbacia eggs by certain dinitrophenols. To yield optimum respiratory effect and maximum division block, it usually requires a higher concentration of dihalo than of the corresponding dinitrophenol. For example, with fertilized Arbacia eggs at 20°C. 2,4-dinitrophenol, in optimum concentration of 3 x 10–5 molar, raises oxygen consumption to 292 per cent of normal (4). The corresponding values for two dihalo analogues are: 2,4-dichlorophenol, 10–4 molar and 236 per cent; 2,4-dibromophenol, 6 x 10–5 molar and 282 per cent. The halophenols differ from the nitrophenols in two interesting respects: (a) The monohalophenols produce little or no oxidative stimulation or division block in fertilized Arbacia eggs; p-nitrophenol is very active in both respects. (b) The symmetrical trihalophenols have an appreciable ability to stimulate oxygen consumption and block division; symmetrical trinitrophenol is inactive in both respects (4). The increases in oxygen consumption produced in fertilized Arbacia eggs by 2,4-dichloro and 2,4-dinitrophenol are larger than the percentage increases given by methylene blue and o-cresol indophenol under the same experimental conditions. The dihalo and dinitrophenols produce a reversible block to the cell division of fertilized marine eggs. The oxidation-reduction indicators, in contrast to the dihalo and dinitrophenols, block cell division irreversibly and fertilized eggs of Arbacia do not recover from optimum respiratory stimulating concentrations of these oxidation-reduction dyes. The present experiments with halophenols are in harmony with and lend considerable support to the hypothesis (4) that nitro and similarly substituted phenols derive their biological activity from the presence and properties of the phenolic OH group, as modified by proper substitution in the phenolic benzene ring.

scholarly journals THE EFFECTS OF URETHANE AND CHLORAL HYDRATE ON OXYGEN CONSUMPTION AND CELL DIVISION IN THE EGG OF THE SEA URCHIN, ARBACIA PUNCTULATA

1944 ◽  
Vol 27 (5) ◽  
pp. 469-481 ◽  
Author(s):  
Kenneth C. Fisher ◽  
R. J. Henry
Keyword(s):  
Oxygen Consumption ◽  
Cell Division ◽  
Sea Urchin ◽  
Chloral Hydrate ◽  
Mass Action ◽  
Law Of Mass Action ◽  
Activity System ◽  
Arbacia Punctulata ◽  
The Law ◽  
Respiratory Systems

The effects of a series of concentrations of the narcotics, ethyl carbamate and chloral hydrate, have been determined on the consumption of oxygen by fertilized and unfertilized eggs of the sea urchin Arbacia punctulata. In the fertilized eggs the effects of the two inhibitors on cell division were also examined. The following observations were made: 1. Assuming that the narcotic acts upon a single catalyst in the unfertilized egg the degree to which the consumption of oxygen is inhibited in this resting cell can be related to the narcotic concentration by an expression derived from the law of mass action. 2. To account for the relation between the concentration of the narcotic and its effect on respiration in the fertilized eggs, it is necessary to conclude that in them the narcotic acts on two parallel respiratory systems. The experimental data can be quantitatively predicted (1) if the reaction of the narcotic on the two systems is governed by the law of mass action and (2) if 40 per cent of the oxygen consumption is mediated by one system, the "activity" system, and the remainder by the other, the "resting" or "basal" system. 3. The mass law constants applying to the resting system in the fertilized egg are similar to those for the single system functioning in the unfertilized egg so that these two respiratory systems are probably identical. 4. The concentrations of the narcotics just sufficient to abolish cell division affect primarily the activity system, the existence of which was inferred from the respiratory experiments. It is concluded that normal cell division requires specifically the normal function of the activity system, that in fact the energy for cell division is made available through that system.

Carbon Monoxide-Neuroglobin Axis Targeting Metabolism Against Neuroinflammation

2021 ◽  
Author(s):  
Daniela Dias-Pedroso ◽  
José S. Ramalho ◽  
Vilma A. Sardão ◽  
John G. Jones ◽  
Carlos C. Romão ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Carbon Monoxide ◽  
Oxygen Consumption ◽  
Inflammatory Response ◽  
Microglial Cell ◽  
Cell Metabolism ◽  
Competent Cell ◽  
Metabolic Shift ◽  
Anti Inflammatory ◽  
Inflammatory Effect

Abstract Microglia are the immune competent cell of the central nervous system (CNS), promoting brain homeostasis and regulating inflammatory response against infection and injury. Chronic or exacerbated neuroinflammation is a cause of damage in several brain pathologies. Endogenous carbon monoxide (CO), produced from the degradation of heme, is described as anti-apoptotic and anti-inflammatory in several contexts, including in the CNS. Neuroglobin (Ngb) is a haemoglobin-homologous protein, which upregulation triggers antioxidant defence and prevents neuronal apoptosis. Thus, we hypothesized a crosstalk between CO and Ngb, in particular, that the anti-neuroinflammatory role of CO in microglia depends on Ngb. A novel CO-releasing molecule (ALF826) based on molybdenum was used for delivering CO in microglial culture.BV-2 mouse microglial cell line was challenged with lipopolysaccharide (LPS) for triggering inflammation, and after 6h ALF826 was added. CO exposure limited inflammation by decreasing inducible nitric oxide synthase (iNOS) expression and the production of nitric oxide (NO) and tumour necrosis factor-a (TNF-a), and by increasing interleukine-10 (IL-10) release. CO-induced Ngb upregulation correlated in time with CO’s anti-inflammatory effect. Moreover, knocking down Ngb reversed the anti-inflammatory effect of CO, suggesting that dependents on Ngb expression. CO-induced Ngb upregulation was independent on ROS signalling, but partially dependent on the transcriptional factor SP1. Finally, microglial cell metabolism is also involved in the inflammatory response. In fact, LPS treatment decreased oxygen consumption in microglia, indicating a switch to glycolysis, which is associated with a proinflammatory. While CO treatment increased oxygen consumption, reverting LPS effect and indicating a metabolic shift into a more oxidative metabolism. Moreover, in the absence of Ngb this phenotype was no longer observed, indicating Ngb is needed for CO’s modulation of microglial metabolism. Finally, the metabolic shift induced by CO did not depend on alteration of mitochondrial population. In conclusion, neuroglobin emerges for the first time as a key player for CO signalling against exacerbated neuroinflammation in microglia.

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 ON THE RATE OF OXYGEN CONSUMPTION BY FERTILIZED AND UNFERTILIZED EGGS

1931 ◽  
Vol 15 (2) ◽  
pp. 167-182 ◽  
Author(s):  
D. M. Whitaker
Keyword(s):  
Oxygen Consumption ◽  
Cell Division ◽  
Fucus Vesiculosus ◽  
High Rate ◽  
Rate Of Oxygen Consumption ◽  
C 50 ◽  
Very High

1. The unfertilized eggs of Fucus vesiculosus, in the dark, consume about 5.2 mm.3 O2 per hour per 10 mm.3 eggs. 2. With an illumination of 100,000 foot candles in photosynthesis they liberate more than twice as much oxygen as they consume. 3. The actively swimming antherozoids or sperm of Fucus consume oxygen at a very high rate: 25.5 mm.3 O2 per hour per 10 mm.3 antherozoids. 4. Immediately following fertilization, in the dark, the Fucus eggs increase the rate of oxygen consumption to about 190 per cent of the prefertilization rate. 5. This rate for fertilized eggs, about 190 per cent, is maintained uniformly for 13 or 14 hours, after which there is a barely perceptible rise until 24 hours (when measurements ceased). At 18°C. 50 per cent of the spores in a population have completed the first cell division about 15 hours after fertilization.

scholarly journals THE EFFECT OF PENICILLIN ON EGGS OF THE SEA URCHIN, ARBACIA PUNCTULATA

1945 ◽  
Vol 28 (5) ◽  
pp. 405-413 ◽  
Author(s):  
Richard J. Henry ◽  
Maryon D. Henry
Keyword(s):  
Oxygen Consumption ◽  
Cell Division ◽  
Sea Urchin ◽  
Inhibitory Action ◽  
Initial Concentration ◽  
Arbacia Punctulata ◽  
Sea Urchin Egg

1. Penicillin in the range of concentration from 250 U/ml. to approximately 2650 U/ml. inhibits the rate of cell division of the fertilized sea urchin egg from 0 to 100 per cent. 2. Penicillin in the same range of concentrations has no effect on the oxygen consumption of the unfertilized or the fertilized eggs. 3. Penicillin is bound by some component of the sea urchin egg in amounts sufficiently large to lower the initial concentration, this binding apparently not being related to the inhibitory action.

scholarly journals GLUCOSE-6-PHOSPHATE AND 6-PHOSPHOGLUCONATE DEHYDROGENASES FROM EGGS OF THE SEA URCHIN, ARBACIA PUNCTULATA

1955 ◽  
Vol 38 (4) ◽  
pp. 431-439 ◽  
Author(s):  
M. E. Krahl ◽  
A. K. Keltch ◽  
C. P. Walters ◽  
G. H. A. Clowes
Keyword(s):  
Oxygen Consumption ◽  
Dehydrogenase Activity ◽  
Sea Urchin ◽  
Maximal Activity ◽  
Glycolytic Pathway ◽  
Supernatant Fraction ◽  
Arbacia Punctulata ◽  
Rate Of Oxygen Consumption ◽  
Wet Weight ◽  
Glucose 6 Phosphate Dehydrogenase

1. Glucose-6-phosphate and 6-phosphogluconate dehydrogenases have been found in homogenates of Arbacia eggs; 95 per cent of the activity toward each substrate is recovered in the supernatant fraction after centrifuging at 20,000 g for 30 minutes. 2. With glucose-6-phosphate as substrate) the rate of TPN reduction by the supernatant fraction from 1 gm. wet weight unfertilized or fertilized eggs was 1.8 to 3.0 micromoles per minute; this rate is sufficient to support a rate of oxygen consumption 24 times that observed for unfertilized, and 6 times that for fertilized, eggs. Pentose was formed from glucose-6-phosphate at a rate 0.3 to 0.5 that of TPN reduction, when both rates were expressed as micromoles per minute. 3. The concentrations of glucose-6-phosphate and 6-phosphogluconate for half maximal activity were each approximately 0.00004 M for the respective enzymes in the supernatant fraction. Maximal activity toward 6-phosphogluconate was 50 to 60 per cent of that toward glucose-6-phosphate. Glucose-6-phosphate dehydrogenase activity was 50 per cent inhibited in presence of 0.00006 M 2,4,5-trichlorophenol. 4. Reduction of DPN by the supernatant fraction in presence of fructose-1,6-diphosphate and ADP was 0.1 to 0.2 micromoles per minute per gm. wet eggs, indicating that the glycolytic pathway can metabolize glucose-6-phosphate at about 5 per cent the rate at which it can be oxidized by the TPN system from unfertilized or fertilized Arbacia eggs. 5. Phosphoglucomutase, hexose isomerase, and a phosphatase for fructose-1,6-diphosphate also appear to be present in Arbacia eggs.

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 STUDIES ON CELL METABOLISM AND CELL DIVISION

1942 ◽  
Vol 25 (5) ◽  
pp. 733-747 ◽  
Author(s):  
M. E. Krahl ◽  
Bernhard J. Jandorf ◽  
G. H. A. Clowes
Keyword(s):  
Cell Division ◽  
Pyruvic Acid ◽  
Cell Metabolism ◽  
Thiamine Hydrochloride ◽  
Anaerobic Conditions ◽  
Arbacia Punctulata ◽  
Quantitative Extraction

1. Methods suitable for the determination of diphosphothiamine (cocarboxylase) in eggs of Arbacia punctulata have been developed. Quantitative extraction of the cocarboxylase was effected by combining the use of thiamine hydrochloride in the extraction fluid with critical adjustment of the pH of extraction to pH 6.3–6.7. 2. The unfertilized eggs were found to contain the equivalent of 2 to 3 micrograms of natural yeast cocarboxylase per gm. of wet eggs; the cocarboxylase content of the 30 minute and 10 hour fertilized eggs was somewhat less (Table III). 3. In preliminary experiments, Arbacia egg cytolysates were found to cause pyruvic acid to disappear. The rate of such disappearance was apparently greater under aerobic than under anaerobic conditions; it was also greater for cytolysates from fertilized eggs than for cytolysates from unfertilized eggs (Table IV).

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.

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