Subcellular flux of potassium and rubidium in amphibian oocytes
To determine the net Rb/sup +/ influx and K/sup +/ efflux at a subcellular level, fully grown and a Ringer's solution where K/sup +/ was substituted for by Rb/sup +/ on a molar bases. For 40 hrs serial samples of the oocytes were cryofixed and cryosectioned for elemental analysis in mM per kg dry weight using electron probe x-ray microanalysis. Oocyte volume remained constant. Net Rb/sup +/ influx showed a slow exponential increase into the nucleus, the yolk-free cytoplasm and the yolk platelets. There was significant K/sup +/ efflux from the nucleus but not from the yolk-free cytoplasm or the yolk. The Na/sup +/ concentration remained unchanged in all compartments during the course of the experiment. There was however a slow but significant increase in the concentration of Cl/sup -/ in each of the subcellular compartments but this increase was not sufficient to balance the observed increase in the sum of K/sup +/ plus Rb/sup +/. Thus Rb/sup +/ accumulates selectively in all three subcellular compartments indicating that Rb/sup +/ is not a good K/sup +/ surrogate in the oocytes. That K/sup +/ demonstrates efflux from the nucleus but not from the cytoplasmic compartments is interpreted to suggest that some of the nuclear K/sup +/ is lost in exchange for Rb/sup +/ but that essentially none of the cytoplasmic K/sup +/ is-lost in exchange for Rb/sup +/. The findings provide strong evidence for adsorption of Rb/sup +/ in the cell.
- Research Organization:
- Univ. of Texas Health Science Center, San Antonio
- OSTI ID:
- 5684318
- Journal Information:
- Physiol. Chem. Phys. Med. NMR; (United States), Vol. 2
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
POTASSIUM
MEMBRANE TRANSPORT
RUBIDIUM
AMPHIBIANS
CATIONS
CELL MEMBRANES
CELL NUCLEI
CHLORIDES
ELECTRON MICROPROBE ANALYSIS
ISOTONIC SOLUTIONS
OOCYTES
SODIUM
ALKALI METALS
ANIMALS
AQUATIC ORGANISMS
CELL CONSTITUENTS
CHARGED PARTICLES
CHEMICAL ANALYSIS
CHLORINE COMPOUNDS
DISPERSIONS
ELEMENTS
GERM CELLS
HALIDES
HALOGEN COMPOUNDS
IONS
MEMBRANES
METALS
MICROANALYSIS
MIXTURES
SOLUTIONS
VERTEBRATES
560301* - Chemicals Metabolism & Toxicology- Cells- (-1987)