Abstract
Thirteen-day-old rats were divided into two groups; one group received 1,2-(1-14C) dipalmitoyl phosphatidylcholine and the other 1-14C palmitic acid in the form of an intraperitoneal injection. One half of the total number of rats in each group was sacrificed 24 hr after injection, and the other half was allowed to survive for 17 days after the injection. Radioactivity incorporated into brain and liver total lipids and into individiual polar lipid components of the brain was determined at both intervals. Phosphatidylcholine was isolated and partially deacylated with phospholipase A2 fromCrotalus Admanteus venom. The ratio of radioactivity FA 2/FA 1 (fatty acid attached to 2 and 1 carbon of the glycerol moiety) 24 hr after the injection was 8.3, when the tracer was radioactive phosphatidylcholine, compared to only 0.7 when radioactive palmitate was injected. From this different labeling ratio and different pattern of labeling the polar lipid components, it was concluded that the radioactive phosphatidylcholine was not deacylated completely before being taken up directly into the brain. Possibilities are discussed to show that the observed radioactive ratio could result from direct uptake of intact phosphatidylcholine, with little or no restriction from the blood brain barrier system, followed by partial degradation by phospholipase A1 in the brain itself.
Similar content being viewed by others
References
Dhopeshwarkar, G.A., C. Subramanian, D.H. McConnel and J.F. Mead, Biochim. Biophys. Acta. 255: 572 (1972).
Davson, H., Advan. Exp. Med. Biol. 13: 381 (1971).
Oldendorf, W.H., Amer., J. Physiol. 221: 1629 (1971).
Hoelzl, J., and H.P., Franck, Second International Meeting, International Society Neurochemistry, September 2, 1969, Milan, p. 219.
Illingworth, D.R., and O.W. Portman, Biochem. J. 130: 557 (1972).
Folch, J., M. Lees and G.H. Sloane-Stanley, J. Biol. Chem. 226: 497 (1957).
Rouser, G., G. Kritchevsky, D. Heller and E. Lieber, JAOCS 40: 425 (1963).
Van Golde, L.M.G., and L.L.M. Van Deenen, Biochim. Biophys. Acta. 125: 496 (1966).
Wells, M.A., and D.J. Hanahan in “Methods of Enzymology”, Vol. 14, Edited by J.M. Lowenstein, Academic Press, New York, N.Y., 1969, p. 178.
Webb, R.A., and D.F. Mettrick, J. Chromatog. 67: 75 (1972).
Dhopeshwarkar, G.A., R. Maier and J.F. Mead, Biochim. Biophys. Acta. 187: 6 (1969).
Dawson, R.M.C., Ibid. 14: 374 (1954).
Dhopeshwarkar, G.A., C. Subramanian and J.F. Mead, Ibid. 296: 57 (1972).
Glomset, J.A., J. Lipid Res. 9: 155 (1968).
Baker, R.R., and W. Thompson, Biochim. Biophys. Acta. 270: 489 (1972).
Montfoort, A., L.M.G. Van Golde and L.L.M. Van Deenen, Ibid. 231: 335 (1971).
Smith, A.D., and H. Winkler, Biochem. J. 108: 867 (1968).
Paysant, M., R. Wald and J. Polonovsky, Bull. Soc. Chim. Biol. 50: 1445 (1968).
Paysant, M., D. Delbauffe, R. Wald and J. Polonovsky, Ibid. 49: 169 (1967).
Paysant, M., and J. Polonovsky, C.R. Acad. Sci. (Paris) 263: 1419 (1966).
Leibovitz, Z., and S. Gatt, Biochim. Biophys. Acta. 164: 439 (1968).
Gatt, S., Ibid. 159: 304 (1968).
Author information
Authors and Affiliations
About this article
Cite this article
Dhopeshwarkar, G.A., Subramanian, C. & Mead, J.F. Metabolism of 1,2-(1-14C) dipalmitoyl phosphatidylcholine in the developing brain. Lipids 8, 753–758 (1973). https://doi.org/10.1007/BF02531844
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF02531844