THE RATE OF OXYGEN CONSUMPTION OF ASTERIAS EGGS BEFORE AND AFTER FERTILIZATION

1931 ◽  
Vol 61 (3) ◽  
pp. 468-471 ◽  
Author(s):  
PEI-SUNG TANG
1982 ◽  
Vol 101 (1) ◽  
pp. 233-254
Author(s):  
D.F. HOULIHAN ◽  
D. SELL

The oxygen consumption of excised abdomens of cockroaches and locusts has been measured before and after the injection of fluids into the ligated recta. Fluid injection caused a transient stimulation of oxygen consumption of up to 30% of the resting rate. The extra amount of oxygen consumed is positively correlated with the osmolality of the fluid injected and the amount of fluid absorbed. Parallel experiments were carried out on the time course of fluid uptake; these experiments revealed a correlation first between a rapid increase in fluid absorption and stimulation of oxygen consumption, and secondly between the final resting rate of oxygen consumption and a slower absorption of fluid. Locusts take up fluid at double the rate of cockroaches and have double the stimulation in oxygen consumption following fluid injection. In locusts the increases in oxygen consumption can also be correlated with the net movement of Na+, K+and Cl− from the rectum. The stimulation of oxygen consumption during fluid uptake is discussed in relation to the local osmosis model for fluid uptake.


1988 ◽  
Vol 138 (1) ◽  
pp. 487-497 ◽  
Author(s):  
MARTIN E. FEDER

To ascertain whether the presence of lungs per se, or some other physiological feature, might account for the differences in oxygen consumption and stamina previously observed in an interspecific comparison (Full et al. 1988), individual salamanders (Ambystoma tigrinum) were exercised on a treadmill before and after their nares and mouth had been sealed. After airway closure, animals behaved normally and suffered no mortality. Airway closure reduced the routine MO2 (rate of oxygen consumption) by an average of 47% in six of seven individuals. Animals with open airways increased their MO2 2-to 4-fold during locomotion at 11 cm s−1, and did not fatigue in 22 min of exercise at this speed. Animals with closed airways managed only small increases above the routine MO2 during exercise at 11 cm s−1, and none could sustain activity for more than 10 min. Thus, exclusively skin-breathing Ambystoma cannot increase cutaneous gas exchange to compensate for the elimination of pulmonary and buccopharyngeal respiration; locomotor stamina suffers accordingly. Small salamanders can apparently increase cutaneous gas exchange during activity, although large salamanders cannot, because cutaneous diffusing capacity and the resting oxygen requirement approach one another with increasing body size; the skin of large salamanders apparently has a limited scope for aerobic activity.


1957 ◽  
Vol 192 (1) ◽  
pp. 73-75 ◽  
Author(s):  
G. R. Vogel ◽  
S. M. Hauge ◽  
F. N. Andrews

The oxygen consumption of normal and hyperthyroid albino rats was measured before and after the intramuscular injection of 1.2 mg (0.2 ml of solution) of procaine penicillin G, Aureomycin or Ilotycin. The final measurements were observed at either 1- or 3-hour intervals after the injection. The antibiotics caused a statistically significant decrease in the rate of oxygen consumption in both normal and hyperthyroid rats. This effect diminished with time. Similar effects were observed with procaine penicillin G after oral administration by stomach tube. It is suggested that antibiotics may somehow influence the endocrine system, possibly the level of circulating thyroxin. Such studies are in progress.


1976 ◽  
Vol 35 (03) ◽  
pp. 712-716 ◽  
Author(s):  
D. Del Principe ◽  
G Mancuso ◽  
A Menichelli ◽  
G Maretto ◽  
G Sabetta

SummaryThe authors compared the oxygen consumption in platelets from the umbilical cord blood of 36 healthy newborn infants with that of 27 adult subjects, before and after thrombin addition (1.67 U/ml). Oxygen consumption at rest was 6 mμmol/109/min in adult control platelets and 5.26 in newborn infants. The burst in oxygen consumption after thrombin addition was 26.30 mμmol/109/min in adults and 24.90 in infants. Dinitrophenol did not inhibit the burst of O2 consumption in platelets in 8 out of 10 newborn infants, while the same concentration caused a decrease in 9 out of 10 adult subjects. Deoxyglucose inhibited the burst in O2 consumption in newborn infant and adult platelets by about 50%. KCN at the concentration of 10−4 M completely inhibited basal oxygen consumption but did not completely inhibit the burst after thrombin. At the concentration of 10−3 M, it inhibited both basal O2 consumption and the burst in infants and adult subjects.


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.


1996 ◽  
Vol 271 (3) ◽  
pp. F717-F722
Author(s):  
G. Bajaj ◽  
M. Baum

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.


1995 ◽  
Vol 41 (4-5) ◽  
pp. 372-377 ◽  
Author(s):  
João P. S. Cabral

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.


1958 ◽  
Vol 41 (5) ◽  
pp. 959-988 ◽  
Author(s):  
W. P. Hurlbut

Azide (0.2 to 5.0 mM) and chloretone (2.0 to 15.0 mM) reversibly inhibited 20 to 90 per cent of the resting respiration of frog sciatic nerves, and caused a loss of potassium and a gain of sodium in this tissue. The changes in ionic contents that developed after 5 or 10 hours were roughly correlated with the degree of respiratory depression, but the time courses of these changes were different with the two reagents. In azide these changes appeared to begin immediately, while in chloretone, at concentrations between 3.0 and 5.0 mM, the ionic shifts developed after a delay of several hours. Fifteen millimolar chloretone produced immediate changes in ionic contents several times greater than those produced by anoxia. The changes in ionic distribution produced in 5 hours by anoxia, 5.0 mM azide, or 5.0 mM chloretone were at least partially reversible; those produced by 15.0 mM chloretone were irreversible. With the exception of 15.0 mM chloretone the ionic shifts produced by these reagents may be due primarily to the depression of the respiration, although there are indications that azide acts, in addition, by another pathway. Concentrations of azide or chloretone that depressed the resting rate of oxygen consumption more than 50 per cent produced a slow conduction block, while 15.0 mM chloretone blocked conduction within 15 minutes.


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