Oxygen consumption and active transport in separated renal tubules

1962 ◽  
Vol 203 (2) ◽  
pp. 327-330 ◽  
Author(s):  
Maurice B. Burg ◽  
Jack Orloff
Keyword(s):  
Oxygen Consumption ◽  
Renal Cortex ◽  
Electrolyte Composition ◽  
Renal Tubules ◽  
Kidney Cells ◽  
Viable Cells ◽  
Rapid Accumulation ◽  
Rate Of Oxygen Consumption ◽  
Cortical Slices ◽  
Uniform Composition

A method for the separation of intact viable cells from rabbit renal cortex has been developed. Separation is achieved by treatment of the excised kidney with the proteolytic enzyme collagenase. The resultant suspension consists principally of short lengths of proximal tubules. Survival of the tissues is indicated by maintenance of oxygen consumption, PAH uptake, and electrolyte composition. Since, in contrast to renal cortical slices, the cells in the tubule suspension are bathed directly by a solution of uniform composition, there is more rapid accumulation of PAH and a higher rate of oxygen consumption in this preparation than in slices. The technique affords a method for the direct measurement of fluxes across membranes of kidney cells.

Effect of strophanthidin on electrolyte content and PAH accumulation of rabbit kidney slices

1962 ◽  
Vol 202 (3) ◽  
pp. 565-571 ◽  
Author(s):  
Maurice B. Burg ◽  
Jack Orloff
Keyword(s):  
Renal Cortex ◽  
Specific Effect ◽  
Cation Transport ◽  
Sodium Content ◽  
Electrolyte Composition ◽  
Rabbit Kidney ◽  
Potassium Depletion ◽  
Bathing Medium ◽  
Cardiotonic Steroid ◽  
Cortical Slices

The cardiac aglycone strophanthidin interferes with cation transport and p-aminohippurate (PAH) accumulation in slices of rabbit renal cortex. Incubation of cortical slices with 3 x 10–5 m strophanthidin results in a depression in slice potassium content, an increase in slice sodium content, and a decrease in the slice to medium ratio for PAH without significantly affecting oxygen consumption. These effects are prevented by increasing the concentration of potassium in the bathing medium. The interference with PAH accumulation is apparently secondary to the associated potassium depletion and does not represent a specific effect of the cardiotonic steroid on PAH transport. No evidence for mineralocorticoid antagonism of the aglycone effect was obtained. The former compounds exert no effects on either the electrolyte composition or PAH accumulation of cortical slices nor do they prevent the response to added strophanthidin.

Sodium and potassium flux of separated renal tubules

1964 ◽  
Vol 206 (3) ◽  
pp. 483-491 ◽  
Author(s):  
Maurice B. Burg ◽  
Evelyn F. Grollman ◽  
Jack Orloff
Keyword(s):  
Renal Cortex ◽  
Renal Tubule ◽  
Renal Tubules ◽  
Efflux Rate ◽  
Active Efflux ◽  
Potassium Flux ◽  
Efflux Rate Constant ◽  
K Transport ◽  
Sodium And Potassium ◽  
Cortical Slices

The Na and K fluxes of renal tubule cells were measured using suspensions of tubules separated from rabbit renal cortex. Kinetic analysis indicates that there are at least two Na compartments and two K compartments in the tubules. The rates at which Na and K exchanged were considerably greater than in renal cortical slices in accordance with predictions based on considerations of the geometrical arrangement of the cells in slices. Digitalis-like steroids, known to depress active cation transport, lowered the efflux rate constant for Na from the major Na compartment and diminished both K influx and the K efflux rate constants. The calculated active efflux of Na greatly exceeded the influx of K, indicating that active Na and K transport are not coupled in a 1:1 ratio.

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.

scholarly journals EFFECTS OF AZIDE AND CHLORETONE ON THE SODIUM AND POTASSIUM CONTENTS AND THE RESPIRATION OF FROG SCIATIC NERVES

1958 ◽  
Vol 41 (5) ◽  
pp. 959-988 ◽  
Author(s):  
W. P. Hurlbut
Keyword(s):  
Oxygen Consumption ◽  
Respiratory Depression ◽  
Conduction Block ◽  
Slow Conduction ◽  
Ionic Distribution ◽  
Rate Of Oxygen Consumption ◽  
Sciatic Nerves ◽  
Time Courses ◽  
Sodium And Potassium

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.

Ontogeny of tracheal fluid, pulmonary surfactant, and plasma corticoids in the fetal lamb

1975 ◽  
Vol 39 (6) ◽  
pp. 1017-1021 ◽  
Author(s):  
E. J. Mescher ◽  
A. C. Platzker ◽  
P. L. Ballard ◽  
J. A. Kitterman ◽  
J. A. Clements ◽  
...  
Keyword(s):  
Pulmonary Surfactant ◽  
Electrolyte Composition ◽  
Plasma Sodium ◽  
Sudden Increase ◽  
Fetal Plasma ◽  
A Value ◽  
Fetal Lamb ◽  
Rapid Accumulation ◽  
Fluid Production ◽  
Change In Mean

We examined fetal plasma corticoids and flow rate, electrolyte composition, and surfactant content of tracheal fluid in chronic experiments with eight fetal lambs. From 120 to 148 days of gestation the rate of fluid production was 4.5 ml/kg per h, and there was no change in mean fluid sodium (147.8 meq/1), chloride (153.1 meq/1), calcium (2.2 mg/100 ml), and pH (6.23). Tracheal fluid potassium increased from 4.3 meq/1 at 120–130 days to 8.9 meq/1 at term, while plasma sodium, chloride, calcium, pH, and potassium were constant at 146.1 meq/1, 110.0 meq/1, 12.1 mg/100 ml, 7.39, and 4.0 meq/1, respectively. Plasma corticoids were less than 1.5 mug/100 ml total (0.3 mug/100 ml free) until 130 days, when they increased rapidly to 10.5 total (3.2 free) at 148 days. Surfactant was first detected in tracheal fluid between 124 and 133 days and its secretion increased rapidly after 135 days to a value of 125 mug/kg per h at 148 days. A sudden increase in fetal plasma corticoids does not seem to be the stimulus for appearance of surfactant in the lamb, although these hormones may induce the rapid accumulation of surfactant prior to delivery.

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