Reduced cholesteryl ester transfer in plasma of patients with lipoprotein lipase deficiency.
The net mass transfer of cholesteryl ester (CE) from high density lipoprotein (HDL) to the apolipoprotein (apo) B-containing lipoproteins, very low density lipoprotein (VLDL) and low density lipoprotein (LDL) in plasma (cholesteryl ester transfer (CET)) from three patients lacking lipoprotein lipase (LpL) activity was significantly lower (P < 0.001) than in plasma from fasting control subjects with comparable triglyceride levels. Chylomicrons isolated from LpL-deficient fasting plasma showed the same low level of CET activity as observed in the intact plasma when combined with HDL and cholesteryl ester transfer protein (CETP)-containing d 1.063 g/ml bottom fractions from control subjects. Preincubation of chylomicrons and large triglyceride-rich lipoproteins (Sf > 400) from LpL-deficient plasma with milk LpL, however, stimulated the capacity to engage in CET 4- to 5-fold to the same level as chylomicrons and VLDL from control subjects after a fat load. Consistent with these measurements of CET activity in plasma, chylomicrons obtained from the LpL-deficient subjects after a 14-h fast had higher TG/CE ratios than chylomicrons from controls 3 h after ingesting a fat load (LpL-deficient 26.3 +/- 9.0 vs. controls 6.9 +/- 2.1; mean +/- SD). The mass of CETP did not differ in LpL-deficient and control subjects (LpL-deficient 1.03 +/- 0.22 micrograms/ml vs. controls 1.58 +/- 0.58 micrograms/ml). These studies are consistent with earlier in vitro studies showing that the actions of lipoprotein lipase and its lipolytic products are essential, for maximal cholesteryl ester transfer protein activity.
Bagdade
J D
JD
Rush Medical College, Chicago, IL, USA.
Ritter
M C
MC
Lithell
H
H
Bassett
D
D
Mailly
F
F
Talmud
P
P
Hayden
M R
MR
D002788:Cholesterol Esters / Q000378:metabolism*; D008076:Cholesterol, HDL / Q000378:metabolism*; D002914:Chylomicrons / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D005215:Fasting / Q000378:metabolism; D005260:Female; D006801:Humans; D006949:Hyperlipidemias / Q000097:blood / Q000201:enzymology / Q000378:metabolism; D008055:Lipids / Q000097:blood; D008071:Lipoprotein Lipase / Q000097:blood / Q000172:deficiency*; D008074:Lipoproteins / Q000097:blood; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D013997:Time Factors
D002788:Cholesterol Esters; D008076:Cholesterol, HDL; D002914:Chylomicrons; D008055:Lipids; D008074:Lipoproteins; D008071:Lipoprotein Lipase