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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
1
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pubmed:dateCreated |
1984-8-3
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pubmed:abstractText |
Young, adult and old male CFY rats (2, 12 and 24 mth of age, respectively) were treated with a daily dose of 30 mg RbCl/100 g body weight, in form of aqueous solution injected intraperitoneally for 14 days. A considerable part of the intracellular K+-content of the body was replaced by Rb+ during this treatment. After cessation of the RbCl injections, a relative steady state came into being in each age group, called Rb+-release period. During this period Rb+ and K+ contents of the blood serum and the cisternal CSF were measured by atomic absorption spectrophotometry, and of the intracellular space of brain cortical cells by energy-dispersive X-ray microanalysis. Ultrastructural features of the brain cortex were also checked by transmission electron microscopy. For X-ray microanalysis, the L-line of Rb at 1.694 keV energy was used at 10 kV accelerating voltage in a scanning electron microscope equipped with an EDAX System F. Rb+ and K+ concentrations were obtained for the cellular dry mass and converted into wet concentrations on the basis of intracellular water contents known from former experiments. Rb+-replacement of K+ did not cause any ultrastructural alteration in the brain cortex. However, the Rb+ accumulation displayed a very significant age-dependent increase: at the beginning of release, adult and old rats had 32.6 and 44.7 mM Rb+ in their intracellular water as against the 8.6 mM found in the young group, and similar proportional difference persisted during 20 days of the release. Rb+ discrimination ratios (DR) calculated either for the blood or the CSF displayed very considerable age-dependent increase: the values of the adult and old groups were 191 and 242% of the young one, indicating that the passive Rb+ (and K+) permeability of the nerve cell membrane decreases throughout the life span of rats. These results give further support to the membrane hypothesis of aging.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
May
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pubmed:issn |
0167-4943
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
3
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
11-31
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pubmed:dateRevised |
2003-11-14
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pubmed:meshHeading |
pubmed-meshheading:6742945-Aging,
pubmed-meshheading:6742945-Animals,
pubmed-meshheading:6742945-Cell Membrane Permeability,
pubmed-meshheading:6742945-Cerebral Cortex,
pubmed-meshheading:6742945-Cerebrospinal Fluid,
pubmed-meshheading:6742945-Electron Probe Microanalysis,
pubmed-meshheading:6742945-Male,
pubmed-meshheading:6742945-Membrane Potentials,
pubmed-meshheading:6742945-Microscopy, Electron,
pubmed-meshheading:6742945-Neurons,
pubmed-meshheading:6742945-Potassium,
pubmed-meshheading:6742945-Rats,
pubmed-meshheading:6742945-Rats, Inbred Strains,
pubmed-meshheading:6742945-Rubidium,
pubmed-meshheading:6742945-Spectrophotometry, Atomic
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pubmed:year |
1984
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pubmed:articleTitle |
Age-dependent decrease of the passive Rb+ and K+ permeability of the nerve cell membranes in rat brain cortex as revealed by in vivo measurement of the Rb+ discrimination ratio.
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pubmed:publicationType |
Journal Article
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