Prolonged retention of doubly labeled phosphatidylcholine in human plasma and erythrocytes after oral administration

Lipids - Tập 27 Số 12 - Trang 1005-1012 - 1992
Claudio Galli1, Cesare R. Sirtori1, Cristina Mosconi1, L. Medini1, G. Gianfranceschi1, Viola Vaccarino2, Carlo Scolastico3
1Center E. Grossi Paoletti for the Study of Hyperlipidemias, University of Milan, Milan, 20133 Italy
2Department of Organic and Industrial Chemistry, School of SciencesUniversity of MilanMilan20133Italy
3Department of Organic and Industrial Chemistry, School of Sciences, University of Milan, Milan, Italy

Tóm tắt

AbstractThe plasma kinetics of a preparation of dilinoleoyl phosphatidylcholine (DLPC) specifically labeled with3H in the choline moiety and with14C in the 2‐fatty acid (FA) were evaluated in six healthy volunteers after oral administration. Retention of both isotopes in plasma exceeded expectations, with a half‐life in the elimination phase of 172.2 h for3H and 69.7 h for14C. Up to 60 d after administration, there were still significant levels of radioactivity present in plasma. The relative stability of the [14C]FA label was demonstrated by the retention for more than 12 h of an isotope ratio close to that of the compound administered. The14C label of DLPC remained in position‐2, as assessed by cleavage of plasma phospholipids with phospholipase A2. The [3H]choline label showed an early incorporation into high density lipoproteins and subsequently into low density lipoproteins (LDL); conversely, the14C radioactivity was rapidly incorporated into triacylglycerols that were mainly associated with very low density lipoproteins. Radioactivity measurements revealed that both isotopes remained the longest time in LDL. In red blood cell (RBC) lipids, [3H]choline radioactivity accumulated over time, with a plateau after 48 h, whereas FA radioactivity accumulated more rapidly and was followed by a progressive decay. Analysis of the isotope ratio in these cells suggested an early incorporation of lyso products followed by rapid transfer of FA from plasma. The RBC maintained considerable radioactivity for a prolonged time, thus acting as a possible reservoir for the DLPC administered. Our study showed that dilinoleoyl PC remained in plasma longer than predicted based on earlier studies, and that after absorption the FA label was found in position 2.

Từ khóa


Tài liệu tham khảo

10.1002/path.1700940111

10.1353/pbm.1984.0031

Crook T., 1988, Psychopharmacol. Bull, 24, 509

10.1172/JCI112975

10.1073/pnas.85.1.242

Wagener H., 1972, Phospholipide, 59

10.1016/S0022-2275(20)42223-0

10.1016/S0022-2275(20)38050-0

10.1515/bchm2.1976.357.2.1321

10.1042/bj1400503

10.1016/S0021-9258(18)32904-1

10.1016/0076-6879(81)71083-8

Scow R.O., 1967, J. Biol. Chem., 183, 123

10.1139/o59-105

10.1021/jo00408a041

10.1172/JCI103182

Roschlau P., 1974, Z. Klin. Chem. Klin. Biochem., 12, 403

10.1016/S0021-9258(18)64849-5

10.1007/BF02531316

10.1002/jps.2600740202

Nilsson A., 1967, Biochim. Biophys. Acta, 70, 490

Ganguly J., 1972, Biochem. Soc. Symp., 35, 67

10.1016/S0022-2275(20)38941-0

10.1016/S0009-9120(82)96758-3

10.1016/0005-2760(73)90138-0

10.1111/j.1365-2362.1979.tb01667.x

10.1016/0005-2760(87)90024-5

10.1016/S0022-2275(20)40584-X

10.1016/S0022-2275(20)38819-2

10.1016/S0022-2275(20)38404-2

10.1038/345634a0

10.3181/00379727-95-23300

Thông tin
Thông tin xuất bản

Lipids

Tập 27 Số 12

1005-1012

Thông tin tác giả