Altered bioenergetics in proliferating renal cells during potassium depletion
Toback, F.G.; Aithal, H.N.; Ordóñez, N.G.; Spargo, B.H.
Laboratory Investigation; a Journal of Technical Methods and Pathology 41(3): 265-267
1979
ISSN/ISBN: 0023-6837 PMID: 470344 Document Number: 148835
DNA synthesis and energy production via glycolysis and oxidative phosphorylation were studied in cells of the inner stripe of the renal red medulla of rats fed a low K diet. Growth of different cell types in the tissue was assessed by [3H]thymidine autoradiography. During K depletion nuclear labeling was increased in collecting tubules, thick limbs of Henle's loop and interstitial cells; K repletion reduced the frequency of labeled nuclei to values similar to or less than control. Glycolytic energy production and the Pasteur effect were studied by measuring lactate production from glucose in tissue slices and energy production in isolated mitochondria was assessed by determination of the ADP: O2 ratio. K depletion was associated with an increment in glycolysis, decrements in mitochondrial energy production and the Pasteur effect. These alterations were reversed by K repletion. The disturbances in glycolysis and mitochondrial respiration in proliferating renal medullary cells found during K depletion simulate the bioenergetic pattern observed in tumor cells. The return of K to the diet induced regression of the hyperplastic cells and abolished the aberrations in energy metabolism; this tissue can be used as a model system for study of the bioenergetics of reversible cell growth.