Maximum rate of oxygen consumption and quantitative histochemistry of succinate dehydrogenase in single muscle fibres ofXenopus laevis

1989 ◽  
Vol 10 (3) ◽  
pp. 221-228 ◽  
Author(s):  
W. J. Van Der Laarse ◽  
P. C. Diegenbach ◽  
G. Elzinga
Keyword(s):  
Oxygen Consumption ◽  
Succinate Dehydrogenase ◽  
Maximum Rate ◽  
Muscle Fibres ◽  
Single Muscle ◽  
Quantitative Histochemistry ◽  
Rate Of Oxygen Consumption

Gas-phase oxidation of hexene-1

1958 ◽  
Vol 244 (1238) ◽  
pp. 345-354 ◽  
Keyword(s):  
Oxygen Consumption ◽  
Gas Phase ◽  
Maximum Rate ◽  
Reaction Rate ◽  
Pressure Change ◽  
Early Stages ◽  
Unusual Form ◽  
Phase Oxidation ◽  
Rate Of Oxygen Consumption ◽  
Gas Phase Oxidation

An investigation has been made of the oxidation of hexene-1 at 263°C. The unusual form of dependency of reaction rate on hydrocarbon pressure obtained when the maximum rate of pressure change is used as a measure of reaction rate is explained by the fact that much of the oxygen is consumed before the maximum rate of pressure change is attained. This, and the observation that the maximum rate of oxygen consumption exhibits a different dependence on hexene concentration compared with the maximum rate of pressure change confirm that maximum rate of pressure change is an invalid measure of reaction rate. Analyses have been made for certain intermediates and products throughout the course of the reaction, and it has been possible to explain many of the experimental features in terms of ideas previously propounded. A decrease in pressure which in many experiments precedes the rapid increase in pressure is attributed to polymerization reactions which predominated over oxidative degradations in the early stages of the reaction, particularly when the olefin is present in excess.

scholarly journals INCREASE IN BACTERIOPHAGE AND GELATINASE CONCENTRATION IN CULTURES OF BACILLUS MEGATHERIUM

1939 ◽  
Vol 23 (1) ◽  
pp. 59-79 ◽  
Author(s):  
John H. Northrop
Keyword(s):  
Oxygen Consumption ◽  
Maximum Rate ◽  
Narrow Range ◽  
Concentration Increase ◽  
Rate Of Increase ◽  
Rate Of Oxygen Consumption

1. The increase in bacteria, phage concentration, and gelatinase concentration in cultures of B. megatherium has been determined. 2. With lysogenic cultures the phage concentration, gelatinase concentration, and bacteria concentration increase logarithmically at first. The phage and gelatinase concentration then decrease while the bacteria concentration increases to a maximum. 3. The results are the same with sensitive cultures if the ratio of phage to bacteria is small. If the ratio of phage to bacteria is large phage, gelatinase, and bacteria concentration all increase at first and then decrease. The maximum rate of increase coincides approximately with the maximum rate of oxygen consumption of the culture. 4. 60–90 per cent of the phage is free from the cells. 5. The amount of phage produced is determined by the combined phage and not by the total phage. 6. Phage is produced during growth of the cells and not during lysis. 7. In a very narrow range of pH near 5.55 no increase in bacteria occurs but large increases in phage may be obtained.

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.

scholarly journals Twitch and Tetanic Tension during Culture of Mature Xenopus laevis Single Muscle Fibres

2001 ◽  
Vol 109 (5) ◽  
pp. 410-417 ◽  
Author(s):  
R.T. Jaspers ◽  
H.M. Feenstra ◽  
M.B.E. Lee-de Groot ◽  
P.A. Huijing ◽  
W.J. van der Laarse
Keyword(s):  
Xenopus Laevis ◽  
Muscle Fibres ◽  
Single Muscle ◽  
Tetanic Tension

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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