Abstract
The incorporation of 1,2-14C-ethanolamine into the liver phosphatidylethanolamines (PE) and phosphatidylcholines (PC) in female rats was studied. These phosphatides were fractionated according to their degrees of unsaturation and the specific activities of monoenoic, dienoic, tetraenoic and hexaenoic fractions were measured at intervals of 1, 20, 60 and 300 min after injection of the labeled precursor. Hexaenoic and dienoic PE incorporated and lost the label rapidly. Although the labeled precursor was incorporated into tetraene PE at a similar rate, this fraction attained a relatively low specific activity that remained essentially constant between 10 and 300 min after injection of the label. Hexaenoic PC had the highest specific activity among the PC fractions at all time periods. Estimations of the rate of loss of radioactivity in the hexaenoic PE fraction and its appearance in hexaenoic PC indicate that the docosahexaenoic acid is conserved, possibly by being reincorporated into PE after becoming a part of the hexaenoic PC species. The high rate of turnover of the hexaenoic PE also suggests that this fraction might have some special role in endogenous choline synthesis.
Similar content being viewed by others
References
Wise, E. M., Jr., and D. Elwyn, J. Biol. Chem. 240:1537 (1965).
Arvidson, G. A. E., European J. Biochem. 5:415 (1968).
Lyman, R. L., S. M. Hopkins, G. Sheehan and J. Tinoco, Biochim. Biophys. Acta 176:86 (1969).
Arvidson, G. A. E., European J. Biochem. 4:478 (1968).
Skipski, V. P., R. F. Peterson and M. Barclay, Biochem. J. 90:374 (1964).
Sumner, J. B., Science 100:413 (1944).
Hopkins, S. M., G. Sheehan and R. L. Lyman, Biochim. Biophys. Acta 164:272 (1968).
Tinoco, J., S. M. Hopkins, D. J. McIntosh, G. Sheehan and R. L. Lyman, Lipids 2:479 (1967).
Akesson, B., European J. Biochem. 9:463 (1969).
Mudd, J. B., L. M. G. Van Golde and L. L. M. Van Deenen, Biochim. Biophys. Acta 176:547 (1969).
Rytter, D., J. E. Miller and W. E. Cornatzer, Ibid. 152:418 (1968).
Yamamoto, A., M. Isozaki, K. Hirayama and Y. Sakai, J. Lipid Res. 6:295 (1965).
Sidransky, H., V. B. Mitbander and S. Clark, J. Nutr. 80:117 (1963).
Bjornstad, P., and J. Bremer, J. Lipid Res. 7:38 (1966).
Author information
Authors and Affiliations
About this article
Cite this article
Tinoco, J., Sheehan, G., Hopkins, S. et al. Incorporation of 1,2-14C-ethanolamine into subfractions of rat liver phosphatidylethanolamines and phosphatidylcholines. Lipids 5, 412–416 (1970). https://doi.org/10.1007/BF02532107
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF02532107