Summary
The objective of this study has been to determine the intracellular localization of calcium in cryofixed, cryosectioned suspensions of kidney proximal tubules using quantitative electron probe X-ray microanalysis. Two populations of cells have been identified: 1) „Viable” cells, representing the majority of cells probed, are defined by their relatively normal K/Na concentration ratio of ∼4∶1. Their measured Ca content is 4.1±1.4 (sem) mmol/kg dry wt in the cytoplasm and 3.1 ± 1.1 mmol/kg dry wt in the mitochondria, or an average cell calcium content of ∼3.8 mmol/kg dry wt. 2) “Nonviable” cells, defined by the presence of dense inclusions in their mitochondria and a K/Na concentration ratio of ∼1. The Ca content is 15±2 mmol/kg dry wt in the cytoplasm and 685±139 mmol/kg dry wt in the mitochondria of such cells. Assuming 25 to 30% of the cell volume is mitochondrial, the overall calcium content of such nonviable cells is ∼ 210 mmol/kg dry wt. The presence of these inclusions in 4 to 5% of the cells would account for the average total Ca content measured in perchloric acid extracts of isolated proximal tubule suspensions (≈ 18 nmol/mg protein or 12.6 mmol/kg dry wt). Whole kidney tissues display a large variability in toal Ca content (4.5 to 18 nmol/mg protein, or 3.4 to 13.5 mmol/kg dry wt), which could be accounted for by inclusion in 0 to 4% of the cells. The electron probe X-ray microanalysis (EPXMA) data conclusively demonstrate that thein situ mitochondrial Ca content of viable cells from the kidney, proximal tubule is low and support the idea that mitochondrial Ca may regulate dehydrogenase activity but probably does not normally control cytosolic free Ca.
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References
Arnold, P.E., Lumlertgul, D., Burke, T.J., Schrier, R.W. 1985. In vitro versus in vivo mitochondrial calcium loading in ischemic acute renal failure.Am. J. Physiol. 248:F845-F850
Balaban, R.S., Soltoff, S., Storey, J.M., Mandel, L.J. 1980. Imporved renal cortical tubule suspension. Spectrophotometric study of O2 delivery.Am. J. Physiol. 238:F50-F59
Beck, F., Bauer, R., Bauer, U., Mason, J., Dörge, A., Rick, R., Thurau, K. 1980. Electron microprobe analysis of intracellular elements in the rat kidney.Kidney Int. 17:756–763.
Becker, G.L., Fiskum, G., Lehninger, A.L. 1980. Regulation of free Ca2+ by liver mitochondria and endoplasmic reticulum.J. Biol. Chem. 255:9009–9012
Bond, M., Shuman, H., Somlyo, A.P., Somlyo, A.V. 1984. Total cytoplasmic calcium in relaxed and maximally contracted rabbit portal vein smooth muscle.J. Physiol. (London) 357:185–201
Denton, R.M., McCormack, J.G. 1980. On the role of the calcium transport cycle in heart and other mamalian motochondria.FEBS Lett. 119:1–8
Hall, T. 1979. Biological x-ray microanalysis.J. Microsc. (Oxford) 117:145–163
Hansford, R.G. 1985. Relation between mitochondrial calcium transport and control of energy metabolism.Rev. Phsyiol. Biochem. Pharmacol. 102:1–72
Hansford, R.G., Castro, F. 1982. Intramitochondrial and extramitochondrial free calcium ion concentrations of suspensions of heart mitochondria with very low, plausibly physiological, contents of total calcium.J. Bioenerg. Biomembr. 14:361–376
Harris, S.I., Balaban, R.S., Barrett, L., Mandel, L.J. 1981. Mitochondrial respiratory capacity and Na+−K+-dependent adenosine triphosphate-mediated ion transport in the intact renal cell.J. Biol. Chem. 256:10319–10328
James-Kracke, M.R., Sloane, B.F., Shuman, H., Karp, R., Somlyo, A.P. 1980. Electron probe analysis of cultured vascular smooth muscle.J. Cell. Physiol. 103:313–322
Joseph, S.K., Coll, K.E., Cooper, R.H., Marks, J.S., Williamson, J.R. 1983. Mechanisms underlying calcium homeostasis in isolated hepatocytes.J. Biol. Chem. 258:731–741
Kitazawa, T., Shuman, H., Somlyo, A.P. 1983. Quantitative electron probe analysis: Problems and solutions.Ultramicroscopy 11:251–262
Kowarski, D., Shuman, H., Somlyo, A.P., Somlyo, A.V. 1985. Calcium release by noradrenaline from central sarcoplasmic reticulum in rabbit main pulmonary artery smooth muscle.J. Physiol. (London) 366:153–175
Kriz, W., Hohling, H.J., Schnermann, J., Rosensteil, A.P. von 1971. Microprobe measurements of electrolytes in kidney sections: First results.Verh. Anat. Ges. 65:217–225
Mandel, L.J. 1982. Metabolic correlates of active transport in renal tubules.In: Functional Regulation at the Cellular and Molecular Levels. R.A. Corradino, editor. pp. 231–244. Elsevier/North-Holland, New York
Mandel, L.J., Murphy, E. 1984. Regulation of cytosolic free calcium levels in rabbit proximal kidney tubules.J. Biol. Chem. 259:11188–11196
Murphy, E., Coll, K.E., Rich, T.L., Williamson, J.R. 1980. Hormonal effects of calcium homeostasis in isolated hepatocytes.J. Biol. Chem. 255:6600–6608
Murphy, E., Mandel, L.J. 1982. Cytosolic free calcium levels in rabbit proximal kidney tubules.Am. J. Physiol. 242:C124-C128
Nicholls, D.G. 1978. The regulation of extramitochondrial free calcium ion concentration by rat liver mitochondria.Biochem. J. 176:463–474
Pfaller, W. 1982. Structure-function correlation on rat kidney.Adv. Anat. Embryol. Cell. Biol. 70:1–106
Saubermann, A.J., Dobyan, D.C., Scheid, V.L., Bulger, R.L. 1986. Rat renal papilla: Comparison of two techniques for x-ray analysis.Kidney Int. 29:675–681
Saubermann, A.J., Scheid, V.L., Dobyan, D.C., Bulger, R.L. 1986. Simultaneous comparison of techniques for x-ray analysis of proximal tubule cells.Kidney Int. 29:682–688
Schmidt-Nielsen, B. 1976. Intracellular concentrations of the salt gland of the herring gullLarus argentatus.Am. J. Physiol. 230:514–521
Shuman, H., Somlyo, A.V., Somlyo, A.P. 1976. Quantitative electron probe microanalysis of biological thin sections: Methods and validity.Ultramicroscopy 1:317–339
Soltoff, S.P., Mandel, L.J. 1984. Active ion transport in the renal proximal tubule. I. Transport and metabolic studies.J. Gen. Physiol. 84:601–622
Soltoff, S.P., Mandel, L.J. 1984. Active ion transport in the renal proximal tubule. II. Ionic dependence of the Na pump.J. Gen. Physiol. 84:623–642
Somlyo, A.P., Bond, M., Somlyo, A.V. 1985. Calcium content of mitochondria and endoplasmic reticulum in liver frozen rapidly in vivo.Nature (London) 314:622–625
Somlyo, A.P., Somlyo, A.V., Shuman, H. 1979. electron probe analysis of vascular smooth muscle: Composition of mitochondria, nuclei and cytoplasm.J. Cell. Biol. 81:316–335
Somlyo, A.P., Somlyo, A.V., Shuman, H., Scarpa, A., Endo, M., Inesi, G. 1981. Mitochondria do not accumulate significant Ca concentrations in normal cells.In: Calcium and Phosphate Transport across Biomembranes. F. Bronner and M. Peterlik, editors. pp. 87–93 Academic, New York
Somlyo, A.P., Somlyo, A.V., Shuman, H., Sloane, B., Scarpa, A. 1978. Electron probe analysis of calcium compartments in cryosections of smooth and striated muscle.Ann. N. Y. Acad. Sci. 307:523–544
Somlyo, A.P., Walz, B. 1985. Elemental distribution inRana pipiens retinal rods: Quantitative electron probe analysis.J. Physiol. (London) 358:183–195
Sommer, J.R., Nassar, R., Walker, S. 1983. Side bridge geometry after quick-freezing of stimulated and unstimulated frog skeletal muscle fibers.Proc. 41st Electron Microsc. Soc. Am. pp. 464–465
Trump, B.F., Berezesky, I.K., Chang, S.H., Bulger, R.E. 1976. Detection of ion shifts in proximal tubule cells of the rat kidney using x-ray microanalysis.Virchows Arch. B. 22:111–120
Weinberg, J.M., Humes, H.D. 1985. Calcium transport and inner mitochondrial membrane damage in renal cortical mitochondria.Am. J. Physiol. 248:F876-F889
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LeFurgey, A., Ingram, P. & Mandel, L.J. Heterogeneity of calcium compartmentation: Electron probe analysis of renal tubules. J. Membrain Biol. 94, 191–196 (1986). https://doi.org/10.1007/BF01871198
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DOI: https://doi.org/10.1007/BF01871198