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1. Intracellular and intercellular concentrations of sodium and potassium have been measured in pregastrular embryos of Xenopus laevis and Amblystoma mexicanum. Calcium and magnesium contents have also been determined.2. Between egg and gastrula stages of development the potassium concentration is near to 60 m-mole/l. embryo. Up to the blastula stage the sodium concentration is near to 50 m-mole/l. embryo; the amount of sodium in the embryo begins to fall just before gastrulation.3. Embryo calcium and magnesium concentrations show no significant variations prior to gastrulation. Average calcium concentrations for the different stages range from 5 to 8 m-mole/l. embryo; magnesium concentrations lie between 12.4 and 17 m-mole/l. embryo.4. The intercellular fluid contains 100 mM sodium and 1 mM potassium; the majority of the sodium is ionically active. As no net uptake of sodium or potassium occurs before gastrulation these cations must have been transferred from the cells to the cavity.5. At all developmental stages studied, the intracellular potassium concentration is close to 100 m-mole/l. cell water. Intracellular sodium falls steadily from 80 m-mole/l. cell water in eggs to 30 m-mole/l. cell water at the beginning of gastrulation.6. The intracellular sodium activity, measured with sodium sensitive intracellular micro-electrodes, is relatively constant between egg and blastula stages at about 14 mM. During each cell division cycle the intracellular sodium activity rises transiently by 2-3 mM.
ADRIAN,
The effect of internal and external potassium concentration on the membrane potential of frog muscle.
1956, Pubmed
ADRIAN,
The effect of internal and external potassium concentration on the membrane potential of frog muscle.
1956,
Pubmed Baker,
Intracellular calcium and cell cleavage in early embryos of Xenopus laevis.
1972,
Pubmed
,
Xenbase Baker,
Depolarization and calcium entry in squid giant axons.
1971,
Pubmed BARTH,
Differentiation of cells of the Rana pipiens gastrula in unconditioned medium.
1959,
Pubmed Blaustein,
The effect of cyanide on the efflux of calcium from squid axons.
1969,
Pubmed Bosher,
Observations on the electrochemistry of the cochlear endolymph of the rat: a quantitative study of its electrical potential and ionic composition as determined by means of flame spectrophotometry.
1968,
Pubmed Century,
The concentrations of water, sodium and potassium in the nucleus and cytoplasm of amphibian oocytes.
1970,
Pubmed Dawid,
Deoxyribonucleic acid in amphibian eggs.
1965,
Pubmed DESMEDT,
Electrical activity and intracellular sodium concentration in frog muscle.
1953,
Pubmed Dick,
The activities and concentrations of sodium and potassium in toad oocytes.
1969,
Pubmed HINKE,
The measurement of sodium and potassium activities in the squid axon by means of cation-selective glass micro-electrodes.
1961,
Pubmed Ito,
Electrical characteristics of Triturus egg cells during cleavage.
1966,
Pubmed JONES,
The culture of small aggregates of amphibian embryonic cells in vitro.
1963,
Pubmed Kalt,
The relationship between cleavage and blastocoel formation in Xenopus laevis. II. Electron microscopic observations.
1971,
Pubmed
,
Xenbase Kalt,
The relationship between cleavage and blastocoel formation in Xenopus laevis. I. Light microscopic observations.
1971,
Pubmed
,
Xenbase KEYNES,
The intracellular calcium contents of some invertebrate nerves.
1956,
Pubmed Kostellow,
Intracellular sodium ion concentration changes in the early amphibian embryo and the influence on nuclear metabolism.
1968,
Pubmed Kroeger,
Regulation of gene action in insect development.
1966,
Pubmed Kuchler,
The role of sodium and potassium in regulating amino acid accumulation and protein synthesis in LM-strain mouse fibroblasts.
1967,
Pubmed MAENO,
Electrical characteristics and activation potential of Bufo eggs.
1959,
Pubmed Morrill,
Water and electrolyte changes in amphibian eggs at ovulation.
1965,
Pubmed Muir,
Variation in the nuclear sodium concentration of newt oocytes during maturation.
1972,
Pubmed NAORA,
Some observations on differences in composition between the nucleus and cytoplasm of the frog oocyte.
1962,
Pubmed Palmer,
Some bio-electric parameters of early Xenopus embryos.
1970,
Pubmed
,
Xenbase PORTZEHL,
THE DEPENDENCE OF CONTRACTION AND RELAXATION OF MUSCLE FIBRES FROM THE CRAB MAIA SQUINADO ON THE INTERNAL CONCENTRATION OF FREE CALCIUM IONS.
1964,
Pubmed Riemann,
Sodium and potassium in oocytes of Triturus cristatus.
1969,
Pubmed Slack,
Intracellular and intercellular potentials in the early amphibian embryo.
1973,
Pubmed
,
Xenbase Stableford,
A study of calcium in the early development of the amphibian embryo.
1967,
Pubmed Thomas,
New design for sodium-sensitive glass micro-electrode.
1970,
Pubmed Thomas,
Membrane current and intracellular sodium changes in a snail neurone during extrusion of injected sodium.
1969,
Pubmed TUFT,
The uptake and distribution of water in the embryo of Xenopus laevis (Daudin).
1962,
Pubmed
,
Xenbase Warren,
The determination of copper and magnesium in blood serum by high-resolution flame spectrophotometry.
1965,
Pubmed Woodward,
Electrical signs of new membrane production during cleavage of Rana pipiens eggs.
1968,
Pubmed
