Intracellular water and ionic shifts during growth and ageing of rats.
As measured by X-ray microanalysis of frozen-dried cryosections, physiological concentrations of phosphorus, Na+, K+ and Mg2+ show a biphasic age dependence in some compartments of rat hepatocytes, especially in the regions of condensed chromatin associated with the actively transcribed genes. This could be consistent with a reactivation of the protein synthesizing apparatus in old livers. The decrease in intracellular water concentrations in hepatocytes and myocytes during ageing is shown to be solely due to a preferential decrease in the water concentration in mitochondria. As a consequence, ionic strength in mitochondria increases with age. This result could provide a rationale for a better understanding of functional declines found in mitochondria from old donors.
D000375:Aging; D000818:Animals; D000838:Anions; D001826:Body Fluids / Q000378:metabolism*; D002412:Cations; D004577:Electron Probe Microanalysis; D007424:Intracellular Fluid / Q000378:metabolism*; D008099:Liver / Q000254:growth & development* / Q000378:metabolism; D008297:Male; D008929:Mitochondria, Heart / Q000378:metabolism; D008931:Mitochondria, Muscle / Q000378:metabolism; D024510:Muscle Development; D009132:Muscles / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains
D000838:Anions; D002412:Cations