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Cerebral metabolism of plasma [14C]palmitate in awake, adult rat: Subcellular localization

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Abstract

Following intravenous injection of [U-14C]palmitate in awake adult rats, whole brain radioactivity reached a broad maximum between 15–60 min, then declined rapidly to reach a relatively stable level between 4 hr and 20 hr. At 44 hr total radioactivity was 57% of the 4 hr value (p<0.05). About 50% of palmitate which entered the brain from the blood was oxidized rapidly, producing14C-labeled water-soluble components which later left the cytosol. Radioactivity in the cytosolic fraction peaked at 45 min and then declined, coincident with the decline in total brain radioactivity. Membrane fractions were rapidly labeled to levels which remained relatively stable from 1 to 44 hr. Increases in the relative distributions of radioactivity were seen between 1 and 4 hr for the microsomal and mitochondrial fractions, and beyond 4 hr for the synaptic and myelin membrane fractions (p<0.05). Radioactivity in membrane fractions was 80–90% lipid, 5–13% water-soluble components and 3–17% protein. The proportion of label in membrane-associated protein increased with time. Proportions of radioactivity in the combined membrane fractions increased from 65% to 76% to 80% at 4, 20 and 44 hr, respectively. The results show that plasma-derived palmitate enters oxidative and synthetic pathways to an equal extent, immediately after entry into the brain. At and after 4 hr, the radiolabel resides predominantly in stable membrane lipids and protein. Brain radioactivity at 4 hr can be used therefore, to examine incorporation of palmitate into lipids in vivo, in different experimental conditions.

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References

  1. Dhopeshwarkar, G. A., and Mead, J. F. 1969. Fatty acid uptake by the brain. II. Incorporation of [1-14C] palmitic acid into the adult rat brain. Biochem. Biophys. Acta 187:461–467.

    PubMed  Google Scholar 

  2. Dhopeshwarkar, G. A., and Mead, J. F. 1973. Uptake and transport of fatty acids into the brain and the role of the blood-brain-barrier system. Pages 104–142,in Paoletti, R., and Kritchevsky D. (eds.), Advances in Lipid Research, Academic Press, New York.

    Google Scholar 

  3. Dhopeshwarkar, G. A., and Mead, J. F. 1975. Age and lipids of the central nervous system: lipid metabolism in the developing brain. Pages 119–132,in Brody, H., Harman, D., and Ordy, J. M. (eds.), Aging, Vol. 1, Raven Press, New York.

    Google Scholar 

  4. Bourre, J. M., Gozlan-Devillierre, N., Daudu, O., and Baumann, N. 1978. Is there a blood-brain relationship for saturated fatty acids during development?, Biol. Neonate 34:182–186.

    PubMed  Google Scholar 

  5. Gozlan-Devillierre, N., Baumann, N. A., and Bourre, J. M. 1976. Mouse brain uptake and metabolism of stearic acid, Biochimie 58:1129–1133.

    PubMed  Google Scholar 

  6. Gozlan-Devillierre, N., Baumann, N. A., and Bourre, J. M. 1978. Distribution of radioactivity in myelin lipids following subcutaneous injection of [1-14C]stearate, Biochim. Biophys. Acta 528:490–496.

    PubMed  Google Scholar 

  7. Gozlan-Devillierre, N., Baumann, N. A., and Bourre, J. M. 1978. Incorporation of stearic acid into brain lipids in the developing brain: blood-brain relationships during development. Dev. Neurosci. 1:153–158.

    PubMed  Google Scholar 

  8. Dhopeshwarkar, G. A., Subramanian, C., and Mead, J. F. 1971. Fatty acid uptake by the brain. IV. Incorporation of [1-14C]linoleic acid into the adult rat brain. Biochim. Biophys. Acta 231:8–14.

    PubMed  Google Scholar 

  9. Dhopeshwarkar, G. A., Subramanian, C., and Mead, J. F. 1971. Fatty acid uptake by the brain V. Incorporation of [1-14C] linolenic acid into adult rat brain, Biochim. Biophys. Acta 239:162–167.

    PubMed  Google Scholar 

  10. Vignais, P. M., Gallagher, C. H., and Zabin, I. 1958. Activation and oxidation of long chain fatty acids by rat brain, J. Neurochem. 2:283–287.

    PubMed  Google Scholar 

  11. Beattie, D. S., and Basford, R. E. 1965. Brain mitochondria-III Fatty acid oxidation by bovine brain mitochondria. J. Neurochem. 12:103–111.

    PubMed  Google Scholar 

  12. Kawamura, N., and Kishimoto, Y. 1981. Characterization of water-soluble products of palmitic acid β-oxidation by a rat brain preparation. J. Neurochem. 36:1786–1791.

    PubMed  Google Scholar 

  13. Sun, G. Y., and Horrocks, L. A. 1973. Metabolism of palmitic acid in the subcellular fractions of mouse brain. J. Lipid Res. 14:206–214.

    PubMed  Google Scholar 

  14. Kimes, A. S., Sweeney, D., London, E. D., and Rapoport, S. I. 1983. Palmitate incorporation into different brain regions in the awake rat, Brain Res. 274:291–301.

    PubMed  Google Scholar 

  15. Tabata, H., Kimes, A. S., Robinson, P. J., and Rapoport, S. I. 1986. Homeostasis of cerebral incorporation of plasma palmitate during aging of the rat, (submitted).

  16. Miller, J. C., Gnaedinger, J. M., and Rapoport, S. I. 1986. Metabolism of plasma-derived fatty acid in rat brain. Trans. Amer. Soc. Neurochem. 17:195.

    Google Scholar 

  17. Miller, J. C., Gnaedinger, J. M., and Rapoport, S. I. 1986. Utilization of plasma fatty acid in rat brain: distribution of [14C]palmitate between oxidative and synthetic pathways, J. Neurochem (in press).

  18. Gnaedinger, J., Miller, J. C., and Rapoport, S. I. 1986. Subcellular distribution of iv injected14C-palmitate in rat brain, Trans. Amer. Soc. Neurochem. 17:302.

    Google Scholar 

  19. Cotman, C. W., Banker, G., Churchill, L., and Taylor, D. 1974. Isolation of postsynaptic densities from rat brain, J. Cell Biol. 63:441–455.

    PubMed  Google Scholar 

  20. Nieto-Sampedro, M., Bussineau, C. M., and Cotman, C. W. 1981. Optimal concentration of iodonitrotetrazolium for the isolation of junctional fractions from rat brain, Neurochem. Res. 6:307–320.

    PubMed  Google Scholar 

  21. Lowry, O. H., Rosebrough, N. J., Farr, A. L., and Randall, R. J. 1951. Protein measurement with Folin phenol reagent, J. Biol. Chem. 193:265–275.

    PubMed  Google Scholar 

  22. Cotman, C. W., and Matthews, D. A. 1971. Synaptic plasma membranes from rat brain synaptosomes: Isolation and partial characterization, Biochim. Biophys. Acta 249:380–395.

    PubMed  Google Scholar 

  23. Miller, R. G., Jr. 1966. Simultaneous Statistical Inference. Pages 76–81, McGraw-Hill, New York.

    Google Scholar 

  24. Dhopeshwarkar, G. A., Subramanian, C., McConnell, D. H., and Mead, J. F. 1972. Fatty acid transport into the brain, Biochim. Biophys. Acta 255:572–579.

    PubMed  Google Scholar 

  25. Sun, G. Y. 1977. Effect of chronic electrical stimulation on incorporation of [1-14C]oleate into glycerolipids of mouse brain, J. Neurochem. 28:1385–1387.

    PubMed  Google Scholar 

  26. Allweis, C., Landau, T., Abeles, M., and Magnes, J. 1966. The oxidation of albumin-bound palmitic acid to CO2 by the perfused cat brain. J. Neurochem. 13:795–804.

    PubMed  Google Scholar 

  27. Spitzer, J. J. 1973. CNS and fatty acid metabolism, Physiologist 16:55–68.

    PubMed  Google Scholar 

  28. Sun, G. Y., and Su, K. L. 1979. Metabolism of arachidonoyl phosphoglycerides in mouse brain subcellular fractions, J. Neurochem. 32:1053–1059.

    PubMed  Google Scholar 

  29. Lees, M. B., and Sakura, J. D. 1978. Preparation of proteolipids. Pages 345–370.In Marks, N., and Rodnight, R. (eds), in Research Methods of Neurochemistry, Volume 4, Plenum Press, New York.

    Google Scholar 

  30. Towsend, L. E., Agrawal, D., Benjamins, J. A., and Agrawal, H. C. 1982. In vitro acylation of rat brain myelin proteolipid protein, J. Biol. Chem. 257:9745–9750.

    PubMed  Google Scholar 

  31. Lajtha, A. L., Maker, H. S., and Clarke, D. D. 1981. Metabolism and transport of carbohydrates and amino acids. Pages 339–341,in Siegel, G. J., Albers, R. W., Agranoff, B. W., and Katzman, R. (eds), in Basic Neurochemistry, Little, Brown and Co., Boston.

    Google Scholar 

  32. Norton, W. T. 1981. Formation, structure, and biochemistry of myelin. Pages 83–87.In Siegel, G. J., Albers, R. W., Agranoff, B. W., and Katzman, R. (eds.), in Basic Neurochemistry, Little, Brown and Co., Boston.

    Google Scholar 

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Authors and Affiliations

  1. Laboratory of Neurosciences National Institute on Aging National Institutes of Health Bethesda, 20892, Maryland

    Jean M. Gnaedinger, Carole H. Latker & Stanley I. Rapoport

  2. Department of Pathology, University of Texas Health Science Center, 75235, Dallas, Texas

    Joseph C. Miller

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  1. Jean M. Gnaedinger
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  2. Joseph C. Miller
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  3. Carole H. Latker
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  4. Stanley I. Rapoport
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Gnaedinger, J.M., Miller, J.C., Latker, C.H. et al. Cerebral metabolism of plasma [14C]palmitate in awake, adult rat: Subcellular localization. Neurochem Res 13, 21–29 (1988). https://doi.org/10.1007/BF00971850

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