TY - JOUR
T1 - Biosynthesis of medium-chain triacylglycerols and phospholipids by HepG- 2 cells
AU - Pakula, Ronit
AU - Rubin, Moshe
AU - Moser, Asher Moshe
AU - Lichtenberg, Dov
AU - Tietz, Alisa
N1 - Funding Information:
This work was supported in part by the Doctor Herman Schauder Memorial Endowment Fund of the Tel Aviv University and by the Minerva Center for Cholesterol, Gallstones and Lipid Metabolism in the Liver at Tel Aviv University. This work was performed in partial fulfillment of the requirements for a Ph.D. degree of Pakula Ronit, Sackler Faculty of Medicine, Tel Aviv University, Israel.
PY - 1997/5
Y1 - 1997/5
N2 - In an attempt to understand the metabolism by the liver of fatty acids (FA) of different chain length, we have studied the incorporation of [1- 14C]-labeled C 2, C 8, C 10, C 12, and C 16 into cellular lipids by HepG-2 cells. Over 90% of the radiolabeled FA were detected in phospholipids (PL) and triacylglycerols (TAG). The incorporation of C 12 and C 16 was three to four times higher than that of C 8 and C 10 (and reached 35 nmoles per mg protein after 1.5 h). The radioactivity of C 2, C 8, and C 10 was recovered mainly in PL. C 12 and C 16 were incorporated at approximately equal amounts into PL and TAG. The radioactivity of both C 2 and C 8 was recovered exclusively in long-chain FA, suggesting oxidation of C 8 into C 2 units prior to FA synthesis. C 10 likewise yielded mainly long-chain FA. However 10% of unchanged C 10 was found in PL and up to 30% in TAG. 14C- C 12 was largely incorporated unchanged. Under these conditions, the presence of C 10 and C 12 in PL and TAG was shown also by gas liquid chromatography. In the presence of either C 2, C 8, or C 10, up to 30% of 14C-monounsaturated FA were detected in PL and TAG. With C 12 and C 16, the fraction of 14C-monounsaturated FA was much smaller suggesting that extensive desaturation occurred during de novo synthesis.
AB - In an attempt to understand the metabolism by the liver of fatty acids (FA) of different chain length, we have studied the incorporation of [1- 14C]-labeled C 2, C 8, C 10, C 12, and C 16 into cellular lipids by HepG-2 cells. Over 90% of the radiolabeled FA were detected in phospholipids (PL) and triacylglycerols (TAG). The incorporation of C 12 and C 16 was three to four times higher than that of C 8 and C 10 (and reached 35 nmoles per mg protein after 1.5 h). The radioactivity of C 2, C 8, and C 10 was recovered mainly in PL. C 12 and C 16 were incorporated at approximately equal amounts into PL and TAG. The radioactivity of both C 2 and C 8 was recovered exclusively in long-chain FA, suggesting oxidation of C 8 into C 2 units prior to FA synthesis. C 10 likewise yielded mainly long-chain FA. However 10% of unchanged C 10 was found in PL and up to 30% in TAG. 14C- C 12 was largely incorporated unchanged. Under these conditions, the presence of C 10 and C 12 in PL and TAG was shown also by gas liquid chromatography. In the presence of either C 2, C 8, or C 10, up to 30% of 14C-monounsaturated FA were detected in PL and TAG. With C 12 and C 16, the fraction of 14C-monounsaturated FA was much smaller suggesting that extensive desaturation occurred during de novo synthesis.
UR - http://www.scopus.com/inward/record.url?scp=0030974311&partnerID=8YFLogxK
U2 - 10.1007/s11745-997-0063-7
DO - 10.1007/s11745-997-0063-7
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AN - SCOPUS:0030974311
SN - 0024-4201
VL - 32
SP - 489
EP - 495
JO - Lipids
JF - Lipids
IS - 5
ER -