Variations in Salinity, Osmolarity, and Water Availability: Vertebrates and Invertebrates

Gllles, Raymond; Delpire, Eric

doi:10.1002/cphy.cp130222

Cited by 14 publications

(10 citation statements)

References 441 publications

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“…In all conditions the absence of external Na ϩ significantly reduced the uptake of K ϩ . Because the requirement for external Na ϩ is not necessarily equivalent to Na ϩ being transported, we next utilized 22 Na to measure the movement of Na ϩ through NKCC1. In this experiment, oocytes were injected with NKCC1 cRNA alone or coinjected with the constitutively active SPAK cRNA, and the bumetanide-sensitive unidirectional influxes of K ϩ and Na ϩ were measured, under either isosmotic or hyperosmotic conditions, in separate groups to avoid overlap of radiation emission signals.…”

Section: Resultsmentioning

confidence: 99%

“…Individual oocytes were then transferred into glass vials, lysed for 1 h with 200 l 0.25N NaOH, and neutralized with 100 l glacial acetic acid and 86 Rb tracer activity was measured by ␤-scintillation counting. Individual oocytes were also placed in plastic tubes for direct measurement of 22 Na tracer activity using a solid Packard ␥-radiation counter. NKCC1-mediated influxes were expressed in nanomoles K ϩ or Na ϩ per oocyte per hour (or min Ϫ1 ).…”

Section: K ϩ and Na ϩ Uptakes In Xenopus Laevis Oocytesmentioning

confidence: 99%

“…In brief, groups of 20 -25 oocytes were incubated for 24 h with L15 containing 1 Ci/ml of either 22 Na, 86 Rb, or 36 Cl. Preliminary experiments have shown that oocytes injected with NKCC1 cRNA and constitutively active SPAK cRNA equilibrate the isotopes to the outside specific activity within 12-24 h. After two 5-l samples were collected to calculate the outside specific activity, the oocytes were rapidly washed four times with ice-cold L15 and individually counted.…”

Section: Ion Content Of Xenopus Laevis Oocytesmentioning

confidence: 99%

“…This is particularly true for osmoconformers, organisms with their internal milieu following the external osmolarity (22). Mammalian cells, however, exist in an environment in which the composition is maintained within very narrow margins by tightly controlled kidney function.…”

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confidence: 99%

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Kinetics of hyperosmotically stimulated Na-K-2Cl cotransporter in Xenopus laevis oocytes

Delpire

Gagnon

2011

American Journal of Physiology-Cell Physiology

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A detailed study of hypertonically stimulated Na-K-2Cl cotransport (NKCC1) in Xenopus laevis oocytes was carried out to better understand the 1 K+:1 Cl− stoichiometry of transport that was previously observed. In this study, we derived the velocity equations for K+ influx under both rapid equilibrium assumptions and combined equilibrium and steady-state assumptions and demonstrate that the behavior of the equations and curves in Lineweaver-Burke plots are consistent with a model where Cl− binds first, followed by Na+, a second Cl−, and then K+. We further demonstrate that stimulation of K+ movement by K+ on the trans side is an intrinsic property of a carrier that transports multiple substrates. We also demonstrate that K+ movement through NKCC1 is strictly dependent upon the presence of external Na+, even though only a fraction of Na+ is in fact transported. Finally, we propose that the larger transport of K+, as compared with Na+, is a result of the return of partially unloaded carriers, which masks the net 1Na+:1K+:2Cl− stoichiometry of NKCC1. These data have profound implications for the physiology of Na-K-2Cl cotransport, since transport of K-Cl in some conditions seems to be uncoupled from the transport of Na-Cl.

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Section: Resultsmentioning

confidence: 99%

Section: K ϩ and Na ϩ Uptakes In Xenopus Laevis Oocytesmentioning

confidence: 99%

Section: Ion Content Of Xenopus Laevis Oocytesmentioning

confidence: 99%

mentioning

confidence: 99%

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Kinetics of hyperosmotically stimulated Na-K-2Cl cotransporter in Xenopus laevis oocytes

Delpire

Gagnon

2011

American Journal of Physiology-Cell Physiology

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“…It is also necessary to examine whether the model is applicable to the in vivo situation. Major changes in cell volume such as those induced in isolated cells by abrupt osmotic shock are unlikely to occur in vivo during osmotic adjustments in the kidney (Gilles and Delpire, 1995). To our knowledge, no changes of such magnitude have ever been demonstrated.…”

Section: Partial Purification Of Aldose Reductasementioning

confidence: 89%

Protein patterns, osmolytes, and aldose reductase of L-929 cells exposed to hyperosmotic media

Libioulle¹,

Llabrès²,

Gilles³

1996

J. Cell. Physiol.

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L-929 cells acclimated to media made hyperosmotic (600 mosmol/kgH2O) by addition of NaCl, sorbitol, or mannitol show, on SDS-polyacrylamide gels, a markedly enhanced protein band at 40 kDa, most likely corresponding to the enzyme aldose reductase. The effect was not observed in cells acclimated to a medium rendered hyperosmotic by addition of proline. The major organic osmolyte accumulated is sorbitol in cells acclimated to high-sorbitol or high-NaCl medium, proline in cells acclimated to high-proline medium. Cells acclimated to any of these hyperosmotic media display unaltered Na+ levels and similarly increased K+ levels and decreased Cl-levels. These results are interpreted in terms of the mechanisms involved in aldose reductase induction and in regulation of the enzyme activity in long-term acclimation to hyperosmotic media.

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Modulation of Sperm Motility and Function Prior to Fertilization

Yoshida

2018

Diversity and Commonality in Animals

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Variations in Salinity, Osmolarity, and Water Availability: Vertebrates and Invertebrates

Cited by 14 publications

References 441 publications

Kinetics of hyperosmotically stimulated Na-K-2Cl cotransporter in Xenopus laevis oocytes

Kinetics of hyperosmotically stimulated Na-K-2Cl cotransporter in Xenopus laevis oocytes

Protein patterns, osmolytes, and aldose reductase of L-929 cells exposed to hyperosmotic media

Modulation of Sperm Motility and Function Prior to Fertilization

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