Effect of heparin-stimulated plasma lipolytic activity on VLDL APO B subclass metabolism in normal subjects.
Heparin given intravenously enhances lipolysis, although fasting lipids are not markedly altered in long-term administration. In the present study we investigated heparin-induced acute perturbation of VLDL subclass metabolism. Eight men were examined during a control study and during an 8.5 h infusion of heparin. 2H3-leucine was used as tracer and kinetic constants derived using a non-steady-state model. Heparin infusion increased both plasma lipoprotein and hepatic lipase activity and raised plasma FFAs two-fold (P < 0.001). The fractional catabolic rate (FCR) of VLDL1 apo B increased on heparin (25.7 +/- 4.2 and 10.8 +/- 1.7 pools/d, heparin vs. control, P < 0.02). The FCR of VLDL2 apo B increased to 12.6 +/- 1.9 pools/d on heparin vs. 8.8 +/- 1.1 pools/d during the control (NS). Total VLDL apo B production was not significantly changed (824 +/- 45 and 692 +/- 91 mg/d, heparin vs. control, NS). We conclude that during heparin infusion, the catabolism of especially large triglyceride-rich VLDL1 apo B is greatly increased. However, although the FFA levels were high during the heparin study, the production of total VLDL apo B did not rise. These findings are consistent with the known action of heparin on lipoprotein lipase but indicate that acute increase in plasma FFA levels does not lead to a rise in VLDL apo B production.
Malmström
R
R
Department of Medicine, University of Helsinki, Helsinki University Central Hospital, Finland.
Packard
C J
CJ
Caslake
M
M
Bedford
D
D
Stewart
P
P
Shepherd
J
J
Taskinen
M R
MR
D000328:Adult; D000925:Anticoagulants / Q000494:pharmacology*; D001055:Apolipoproteins B / Q000378:metabolism*; D001786:Blood Glucose / Q000378:metabolism; D015243:Cholesterol, VLDL / Q000378:metabolism*; D005230:Fatty Acids, Nonesterified / Q000097:blood; D008401:Gas Chromatography-Mass Spectrometry; D006493:Heparin / Q000494:pharmacology*; D006801:Humans; D007328:Insulin / Q000097:blood; D008049:Lipase / Q000378:metabolism; D008066:Lipolysis / Q000187:drug effects*; D008071:Lipoprotein Lipase / Q000097:blood; D008099:Liver / Q000201:enzymology; D008297:Male; D008875:Middle Aged; D012016:Reference Values
D000925:Anticoagulants; D001055:Apolipoproteins B; D001786:Blood Glucose; D015243:Cholesterol, VLDL; D005230:Fatty Acids, Nonesterified; D007328:Insulin; D006493:Heparin; D008049:Lipase; D008071:Lipoprotein Lipase