Participation of Rat Liver Nuclei in Movements of Sodium

Langendorf, H.; Siebert, G.; Nitz-Litzow, D

doi:10.1038/204888a0

Cited by 18 publications

(8 citation statements)

References 4 publications

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“…Disappearance of nuclei from the 39K+ and 23Na+ images suggests that cytoplasm, initially more emissive than nuclei, loses these cations more rapidly. This result is in agreement neither with the commonly accepted opinion that the nuclear ions are more rapidly exchanged than the cytoplasmic ones [9,17,21], nor with the SIMS microscopy results showing that cell nuclei are highly emissive after most types of preparation [24]. This contradiction may be resolved if one considers that our material had been fixed with a precipitating agent.…”

Section: Action Of Water On the Sectionssupporting

confidence: 81%

Preservation of the diffusible cations for secondary ion mass spectrometry. II. Artefacts in material embedded in araldite or melamine

Mentré¹,

Escaig²

1992

Biology of the Cell

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Flotation on hot water (about 60 degrees C) which is frequently employed to stretch semithin sections on substrates for SIMS (secondary ion mass spectrometry) microscopy, is the cause of numerous artefacts. In the case of epoxy resin-embedded tissue, one observes loss of potassium and sodium and accumulation of calcium. The relative contrast of cell nuclei in the ionic images, is rapidly affected by these ion migrations. After prolonged contact with hot water, tissue becomes uniformly emissive. In the case of hydrosoluble resin-embedded tissue, potassium and sodium do not appear to be affected by the action of water, which suggests that they are covalently bound with chelating sites buried beneath the layer of water bound to the surface of the macromolecules. Calcium accumulates, probably on widely exposed anionic sites. Moreover, the domains observed in hydrosoluble resin-embedded tissue shrink differently according to the proportion of water removed by melamine; this can provide interesting information on the initial equilibrium between water, ion sand macromolecules. Our results seem to support the assumption that bound water should play an important role in the preservation of both macromolecular architecture and ion distributions.

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Section: Action Of Water On the Sectionssupporting

confidence: 81%

Preservation of the diffusible cations for secondary ion mass spectrometry. II. Artefacts in material embedded in araldite or melamine

Mentré¹,

Escaig²

1992

Biology of the Cell

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“…In previous studies, it was suggested that the endoplasmic reticulum could serve as a functional channel network to span the distance between plasma membrane and nucleus (4,5). An alternative explanation for the observed phenomenon could be a nonuniform distribution of Na+ transporters in the apical plasma membrane.…”

Section: Resultsmentioning

confidence: 98%

“…Since the activation of genes depends on the actual Na' and K+ concentration in the nucleoplasm (4,5,(21)(22)(23), a rapid and direct cross talk between extracellular space and nucleus could be important to control basic processes such as gene activation, cell growth, and cell differentiation.…”

Section: Discussionmentioning

confidence: 99%

“…Giant cells (diameter, 50-200 ,um) grown on glass were superfused with modified Ringer's solution composed of 122.5 mM NaCl, 5.4 mM KCI, 1.2 mM CaC12, 0.8 mM MgCl2, 1.0 mM Na2HPO4, 10 mM Hepes, 5.5 mM glucose, and titrated to pH 7.4. The experiments were videotaped and the distances between the sites of measurements of the Na' signal were determined.…”

Section: Methodsmentioning

confidence: 99%

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Patchy accumulation of apical Na+ transporters allows cross talk between extracellular space and cell nucleus.

Oberleithner

Wünsch²,

Schneider³

1992

Proc. Natl. Acad. Sci. U.S.A.

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“…The lack of ouabain inhibition of ATP hydrolysis stimulated by Nai-or K+ in the absence of amino acid supports the assumption that the effect of these cations on the enzyme is not related to their transport across the nuclear membrane per se. In this respect, qualified results using thymus nuclei [22] do not support the latter possibility, and other work on isolated rat liver nuclei give no evidence for active transport of Na+ [8,28]. Even though Na+ is concentrated in the nucleus about I1 : 1 compared to the cytoplasm.…”

Section: Discussioymentioning

confidence: 41%

Evidence for an Amino Acid Transport System in Nuclei Isolated from Embryonic Heart

Klein

Horton

Thureson‐Klein

1968

European Journal of Biochemistry

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Nuclei isolated from embryonic myocardium of the chick possess an ATP phosphohydrolase and are capable of accumulating amino acid in a diffusible form in large excess of environmental levels. The enzyme is of relatively high specific activity and shows preference for ATP compared to other possible substrates. Properties common to both the enzyme and to net amino acid uptake are requirements for ATP, Mg++, Na+ or K+ and a critical level of Ca++. I n the presence of Na+ or K+, both L-and D-forms of several amino acids will further stimulate ATP hydrolysis. The latter stimulation by a-alanine and the net uptake of this amino acid can both be completely inhibited by similar concentrations of ouabain, EGTA and excess Ca++. Ouabain has no effect on basic Mg++-activated ATP hydrolysis or that stimulated by the addition of Na+ or K+. It is concluded that these nuclei possess an ATP phosphohydrolase-linked transport system for a-alanine and probably for other amino acids:Implications of this transport system are discussed relative to the ultrastructure and compartmentalization of the cardiac cell.It was initially observed in early 1964 at the Wenner-Gren Institute, Stockholm by Klein and Afzelius [I] that "presumptive" ATP hydrolysis activity could be localized close t o the inner nuclear membrane and prominently a t nuclear pores of chick embryonic ventricular muscle, using a modified histochemical test in con junction with electron microscopy. Unfortunately, the method is susceptible to a number of possible artifacts which allow a t most qualified acceptance of this finding until more rigorous controls are employed. However, similar localization in nuclei of mouse choroid plexus epithelial cells also has been described by Yasuzumi and Tsubo [2], using methods and material which they claim are relatively free from artifacts. The existence of nucleoside triphosphatase a t these loci could have important implications and warrants further investigation concerning possible function in nuclear membrane transport. That this topic is of major concern to those interested in the role of the nucleus in nucleoprotein synthesis and nuclearcytoplasmic exchange is evidenced from numerous speculations found in the recent literature [3 -91.Unusual Abbreviations. EGTA, ethylene glycol bis(Paminoethy1ether)-N,N'-tetraacetic acid; TES, N-Tris-(hydroxymethyl)methyl-2-aminoethane sulfonic acid; PPO, 2,5-diphenyloxazole; POPOP, 1,4-bis-(5-phenyloxazolyl-2)-benzene.Enzymes. ATPase or ATP phosphohydrolase (EC 3.6.1.3) ; alkaline phosphatase or orthophosphoric monoester phosphohydrolase (EC 3.1.3.1) ; acid phosphatase or orthophosphoric monoester phosphohydrolase (EC 3.1.3.2).Subsequent studies in this laboratory on embryonic heart nuclei confirmed the presence of a Mg++-activated adenosine triphosphate phosphohydrolase (ATPase) of relatively high specific activity and with preference for ATP compared to other nucleoside triphosphates and a variety of di-and monophosphates. A number of chemical and physical properties of the enzyme have been de...

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Participation of Rat Liver Nuclei in Movements of Sodium

Cited by 18 publications

References 4 publications

Preservation of the diffusible cations for secondary ion mass spectrometry. II. Artefacts in material embedded in araldite or melamine

Preservation of the diffusible cations for secondary ion mass spectrometry. II. Artefacts in material embedded in araldite or melamine

Patchy accumulation of apical Na+ transporters allows cross talk between extracellular space and cell nucleus.

Evidence for an Amino Acid Transport System in Nuclei Isolated from Embryonic Heart

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