Lipoprotein lipase and hepatic lipase: their relationship with HDL subspecies Lp(A-I) and Lp(A-I,A-II).
HDL subspecies Lp(A-I) and Lp(A-I,A-II) have different anti-atherogenic potentials. To determine the role of lipoprotein lipase (LPL) and hepatic lipase (HL) in regulating these particles, we measured these enzyme activities in 28 healthy subjects with well-controlled Type 1 diabetes, and studied their relationship with Lp(A-I) and Lp(A-I,A-II). LPL was positively correlated with the apolipoprotein A-I (apoA-I), cholesterol, and phospholipid mass in total Lp(A-I), and with the apoA-I in large Lp(A-I) (r >or= 0.58, P >or= 0.001). HL was negatively correlated with all the above Lp(A-I) parameters plus Lp(A-I) triglyceride (r >or= -0.53, P <or= 0.003). No correlation was detected between LPL and Lp(A-I,A-II). However, HL was inversely correlated with total Lp(A-I,A-II) phospholipid, and with large Lp(A-I,A-II) (r >or= 0.50, P <or= 0.006). Similar studies were performed with phospholipid transfer protein (PLTP). Only total Lp(A-I) triglyceride in women (not men) (r = 0.71, P = 0.009) was significantly correlated with PLTP activity. These observations indicate that LPL and HL play major roles in determining the level and composition of plasma Lp(A-I), particularly large Lp(A-I), but not with Lp(A-I,A-II) level. Furthermore, select correlations of LPL and/or HL with the apoA-I, cholesterol, and triglyceride of Lp(A-I) but not Lp(A-I,A-II) imply that the apoA-I and lipid of Lp(A-I) and Lp(A-I,A-II) are not fully equilibrated.
Cheung
Marian C
MC
Department of Medicine, University of Washington, Seattle, WA 98103, USA. mccheung@u.washington.edu
Sibley
Shalamar D
SD
Palmer
Jerry P
JP
Oram
John F
JF
Brunzell
John D
JD
D000328:Adult; D002352:Carrier Proteins / Q000097:blood / Q000378:metabolism; D005260:Female; D006493:Heparin / Q000378:metabolism; D006801:Humans; D008049:Lipase / Q000378:metabolism*; D008071:Lipoprotein Lipase / Q000378:metabolism*; D008075:Lipoproteins, HDL / Q000097:blood / Q000145:classification* / Q000378:metabolism*; D008099:Liver / Q000201:enzymology*; D008297:Male; D008565:Membrane Proteins / Q000097:blood / Q000378:metabolism; D008875:Middle Aged; D049294:Phospholipid Transfer Proteins; D012727:Sex Characteristics
D002352:Carrier Proteins; D008075:Lipoproteins, HDL; D008565:Membrane Proteins; D049294:Phospholipid Transfer Proteins; D006493:Heparin; D008049:Lipase; D008071:Lipoprotein Lipase