Exchange diffusion and runout of Diodrast-I131 from renal tissue in vitro

1961 ◽  
Vol 201 (2) ◽  
pp. 309-317 ◽  
Author(s):  
William B. Kinter ◽  
Allen L. Cline
Keyword(s):  
Low Temperature ◽  
Organic Acids ◽  
Renal Tissue ◽  
Metabolic Inhibition ◽  
Metabolic Inhibitors ◽  
Lipid Solubility ◽  
Facilitated Diffusion ◽  
Complex Membrane ◽  
Tubular Transport

Runout of preaccumulated Diodrast-I131 from isolated goldfish kidneys was investigated with particular attention to metabolic inhibition, competition by related organic acids, and low temperature. Addition of metabolic inhibitors, such as cyanide, to medium bathing the tissue increased Diodrast runout, i.e., rate of net movement into medium. In conjunction with these same inhibitors, competitors either decreased or further increased runout, e.g., probenecid exhibited the former and p-aminohippurate (PAH) the latter action. In the absence of metabolic inhibition, increasing medium concentration of a given competitor first increased and then decreased runout. Low temperature decreased control runout as well as actions of competitors and metabolic inhibitors. Differences in lipid solubility correlate with differences in action of particular competitors. These results are interpreted as evidence for a complex membrane process mediating outward Diodrast movement, e.g., a carrier cycle which exhibits characteristics of both exchange and facilitated diffusion. Speculatively, such a process could be the basis for both active secretion and reabsorption, i.e., bidirectional tubular transport of organic acids.

scholarly journals Characteristics of Ion Transport in Kidney Cortex of Mammalian Hibernators

1966 ◽  
Vol 49 (6) ◽  
pp. 1221-1239 ◽  
Author(s):  
J. S. WILLIS
Keyword(s):  
Low Temperature ◽  
Initial Rate ◽  
Ground Squirrels ◽  
Metabolic Inhibitors ◽  
Kidney Cortex ◽  
Cortex Slices ◽  
State Concentration ◽  
Kidney Cortex Slices ◽  
K Transport

Slices of kidney cortex of two species of hibernating mammals (hamsters and ground squirrels) have been leached of K, and their subsequent ability to reaccumulate K in vitro has been determined at temperatures between 38° and 0°C. At 5°C (body temperature of a hibernating mammal) uptake is appreciable in kidney cortex of both species. In the kidney cortex of hamsters, for example, the tissue K of slices incubated at 5°C reaches the same steady-state concentration after 2 hours that is observed in slices at 38°C after 20 minutes. At 0°C there is also a measurable uptake. This K transport is blocked by metabolic inhibitors and, in ground squirrel kidneys, by ouabain. In kidney cortex slices from guinea pigs net K accumulation is slight at 5°C and absent at 0°C. The initial rapid uptake of K at 38°C occurs at the same rate in kidney cortex slices of hamsters as in those of rabbits. Lowering the temperature of incubation decreases this initial rate of uptake in hamster kidney slices with a Q10 of 1.8 between 38° and 15° and of 5.7 between 15° and 0°C. In hamsters this uptake of K has been shown to require the outward extrusion of Na. Conversely, about half of the outward extrusion of Na requires K in the medium, while the remainder appears to be independent of K. The conclusions warranted are that kidney cells of hibernators possess an unusual ability to transport ions at low temperature, that this ability does not depend upon a more rapid rate at higher temperatures, and that the characteristics of transport at low temperature are qualitatively similar to those at 38°C in cells of nonhibernators.

Ascorbic acid transport in mammalian kidney

1986 ◽  
Vol 250 (4) ◽  
pp. F627-F632 ◽  
Author(s):  
R. C. Rose
Keyword(s):  
Ascorbic Acid ◽  
Brush Border Membrane ◽  
Renal Tissue ◽  
Metabolic Inhibitors ◽  
Bathing Solution ◽  
Acid Transport ◽  
Low Concentrations ◽  
Sodium Dependent ◽  
Ascorbic Acid Transport

Ascorbic acid is known to circulate free in the plasma of several species and is therefore filtered in the kidney; reabsorption subsequently takes place and prevents urinary loss. However, no specific mechanism of renal ascorbic acid transport has previously been presented. In the present study, rat and guinea pig kidney were incubated as slices or as isolated tubules in vitro in the presence of low concentrations of [14C]ascorbic acid. The kidneys of both species handle ascorbic acid similarly. Ascorbic acid accumulates in the renal tissue to a concentration three to four times that present in the bathing media. Recently absorbed ascorbic acid diffuses freely from the kidney and is predominantly nonmetabolized during absorption. Uptake is reduced following replacement of bathing solution sodium by lithium or cesium, or when incubation is performed in the presence of metabolic inhibitors or at low temperatures. The results indicate that ascorbic acid is reabsorbed in the kidney by a sodium-dependent active transport mechanism that operates by concentrating ascorbic acid in the cellular fluid. Renal slices and tubules both appear to transport ascorbic acid and galactose across the brush-border membrane; this indicates that the tubular lumens in these preparations are not collapsed or sealed off.

scholarly journals Effects of temperature, metabolic inhibitors and some other factors on fluid-phase and adsorptive pinocytosis by rat peritoneal macrophages

1979 ◽  
Vol 180 (3) ◽  
pp. 567-571 ◽  
Author(s):  
M K Pratten ◽  
J B Lloyd
Keyword(s):  
Low Temperature ◽  
Energy Supply ◽  
Cytochalasin B ◽  
Fluid Phase ◽  
Peritoneal Macrophages ◽  
Metabolic Energy ◽  
Metabolic Inhibitors ◽  
Dibutyryl Cyclic Amp ◽  
Effects Of Temperature

Low temperature, NaF and 2,4-dinitrophenol could each abolish the pinocytic uptake of 125I-labelled poly(vinylpyrrolidone) or colloidal [198Au]gold by rat peritoneal macrophages cultured in vitro. Cytochalasin B caused only partial inhibition, even at 10 microgram/ml, and colchicine (10 or 25 microgram/ml) inhibited uptake of colloidal [198Au]gold much more than that of 125I-labelled poly(vinylpyrrolidone). Dibutyryl cyclic AMP and ouabain were without effect on uptake of 125I-labelled poly(vinylpyrrolidone), and slight stimulation was seen with ATP and theophylline. Uptake of 125I-labelled poly(vinylpyrrolidone) was abolished by EGTA (5mM), but restored by adding CaCl2 (5mM). The results appear not to support the conventional criteria for the division of pinocytic phenomena into macropinocytosis, requiring a metabolic energy supply and cytoskeletal components, and micropinocytosis, requiring neither.

scholarly journals STUDIES OF THE CHLORIDE TRANSPORT IN THE GASTRIC MUCOSA OF THE FROG

1957 ◽  
Vol 41 (1) ◽  
pp. 101-117 ◽  
Author(s):  
Erich Heinz ◽  
Richard P. Durbin
Keyword(s):  
Gastric Mucosa ◽  
Structural Damage ◽  
Chloride Transport ◽  
Electrical Potential ◽  
Metabolic Inhibition ◽  
Radioactive Isotopes ◽  
Metabolic Inhibitors ◽  
Electrical Potential Difference ◽  
The Relationship

The unidirectional fluxes of Cl- and Na+ across the frog gastric mucosa in vitro were investigated with radioactive isotopes, and related to the secretory and electrical properties of the normal, and metabolically inhibited, mucosa. The flux of Cl- from nutrient to secretory surface of the mucosa was observed to rise sharply with increasing acid secretion, while the corresponding flux of Na+ did not change appreciably. Lowering [NaCl] in the secretory solution caused a proportional drop in the fluxes from secretory to nutrient surface, of both Cl- and Na+. Under the same conditions, the flux of Cl- from nutrient to secretory surface fell by nearly the same amount as did the flux of Cl- in the opposite direction, while the flux of Na+ from nutrient to secretory surface remained essentially unchanged. Electrical and hydrodynamic causes for this observation could be excluded. Metabolic inhibitors, including cyanide, azide, DNP, and anaerobiosis depressed Cl- flux in both directions distinctly below the corresponding values observed with the normal, non-secreting mucosa. At the same time, a decrease in electrical potential difference and conductance was observed under inhibition. The flux of Na+ was little changed by metabolic inhibition. The relationship between fluxes and conductance of Cl- during metabolic inhibition differs markedly from that observed under normal conditions, and is consistent with the view that during metabolic inhibition most of the Cl- moving across the mucosa does so as a free ion. From the above data it is concluded that Cl- is normally transported across the mucosa in combination with a carrier, the supply of which is impaired under metabolic inhibition. According to the behavior of the Na+ flux, the passive permeability of the mucosa appeared to be little affected by the metabolic inhibition applied, but seemed to rise considerably after death of the mucosa, probably due to structural damage.

scholarly journals FURTHER OBSERVATIONS ON UPTAKE OF S35-LABELLED SULFATE BY RENAL TISSUE IN VITRO

1956 ◽  
Vol 39 (6) ◽  
pp. 893-908 ◽  
Author(s):  
Ingrith J. Deyrup
Keyword(s):  
Rat Kidney ◽  
Mammalian Species ◽  
Renal Tissue ◽  
Metabolic Inhibitors ◽  
Kidney Cortex ◽  
Rat Kidney Cortex ◽  
Lower Vertebrates ◽  
The One

Additional studies have been made of the accumulation of S35 by renal cortical tissue incubated in media containing radiosulfate. This process was found to occur in several mammalian species in addition to the rat, but was not observed as a significant occurrence in three species of lower vertebrates. In the case of rat renal tissue, S35 uptake was found to be sensitive to the pH and osmolar concentration of the medium. The character of the anions present in conjunction with K+ affected it as well. Various factors known to be related to in vitro accumulative processes, as well as to renal sulfate reabsorption by the intact dog, were tested on rat kidney cortex to assess the effect on radiosulfate uptake. In general, all substances tested (amino acids, metabolic intermediates, ATP, metabolic inhibitors, competitive inhibitors for PAH accumulation in vitro) were found to lessen S35 uptake, or to be without effect upon it. The one striking exception was phlorhizin, which enhanced markedly S35 uptake in vitro, as it does sulfate reabsorption in vivo. Some implications of these findings have been discussed.

Three-dimensional Growth of Renal Epithelial Cells in Vitro: A Tool in Toxicity Testing

1993 ◽  
Vol 21 (2) ◽  
pp. 191-195 ◽  
Author(s):  
Knut-Jan Andersen ◽  
Erik Ilsø Christensen ◽  
Hogne Vik
Keyword(s):  
Epithelial Cells ◽  
Three Dimensional ◽  
Toxicity Testing ◽  
Renal Tissue ◽  
Epithelial Cell Line ◽  
Multicellular Spheroids ◽  
Renal Epithelial Cell ◽  
Renal Epithelial Cells

The tissue culture of multicellular spheroids from the renal epithelial cell line LLC-PK1 (proximal tubule) is described. This represents a biological system of intermediate complexity between renal tissue in vivo and simple monolayer cultures. The multicellular structures, which show many similarities to kidney tubules in vivo, including a vectorial water transport, should prove useful for studying the potential nephrotoxicity of drugs and chemicals in vitro. In addition, the propagation of renal epithelial cells as multicellular spheroids in serum-free culture may provide information on the release of specific biological parameters, which may be suppressed or masked in serum-supplemented media.

FURTHER STUDIES ON A SOLUBLE ANDROGEN-MACROMOLECULAR COMPLEX FROM THE RAT VENTRAL PROSTATE

1970 ◽  
Vol 65 (3) ◽  
pp. 517-524 ◽  
Author(s):  
Olav Unhjem
Keyword(s):  
Hydrogen Atom ◽  
Keto Group ◽  
Ventral Prostate ◽  
Metabolic Inhibitors ◽  
Macromolecular Complex ◽  
Structural Requirements ◽  
Macromolecular Complexes ◽  
Rat Ventral Prostate

ABSTRACT The ability of various steroids and metabolic inhibitors to influence the binding of androgen to soluble macromolecules in the rat ventral prostate was evaluated in vitro. The results obtained revealed some structural requirements of steroids for binding to the macromolecules. An androstane skeleton with the α-configuration of the hydrogen atom at position 5 seemed to be essential for binding as well as a keto group at position 3. N-ethylmaleimide, Na-iodoacetate and p-hydroxymercuribenzoate inhibited the binding of androgen to macromolecules. The androgen-macromolecular complexes appeared to be rather stable at temperatures below 5°C.

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