Altered distribution of plasma PAF-AH between HDLs and other lipoproteins in hyperlipidemia and diabetes mellitus.
Platelet-activating factor acetylhydrolase (PAF-AH) is a phospholipase A2 associated with lipoproteins that hydrolyzes platelet-activating factor (PAF) and oxidized phospholipids. We have developed an ELISA for PAF-AH that is more sensitive than previous methods, and have quantified HDL-associated and non-HDL-associated PAF-AH in healthy, hyperlipidemic, and diabetic subjects. In healthy subjects, plasma total PAF-AH concentration was positively correlated with PAF-AH activity and with plasma total cholesterol, triacylglycerol, LDL cholesterol and apolipoprotein B (apoB) concentrations (all P < 0.01). HDL-associated PAF-AH concentration was correlated positively with plasma apoA-I and HDL cholesterol. Subjects with hyperlipidemia (n = 73) and diabetes mellitus (n = 87) had higher HDL-associated PAF-AH concentrations than did controls (P < 0.01). Non-HDL-associated PAF-AH concentration was lower in diabetic subjects than in controls (P < 0.01). Both hyperlipidemic and diabetic subjects had lower ratios of PAF-AH to apoB (P < 0.01) and higher ratios of PAF-AH to apoA-I (P < 0.01) than did controls. Our results show that the distribution of PAF-AH mass between HDLs and LDLs is determined partly by the concentrations of the lipoproteins and partly by the mass of enzyme per lipoprotein particle, which is disturbed in hyperlipidemia and diabetes mellitus.
Kujiraoka
Takeshi
T
Department of Advanced Medical Technology and Development, BML, Inc., Saitama, Japan.
Iwasaki
Tadao
T
Ishihara
Mitsuaki
M
Ito
Mayumi
M
Nagano
Makoto
M
Kawaguchi
Akito
A
Takahashi
Sadao
S
Ishi
Jun
J
Tsuji
Masahiro
M
Egashira
Tohru
T
Stepanova
Irina P
IP
Miller
Norman E
NE
Hattori
Hiroaki
H
D043203:1-Alkyl-2-acetylglycerophosphocholine Esterase / Q000097:blood* / Q000235:genetics / Q000378:metabolism; D000911:Antibodies, Monoclonal / Q000276:immunology; D001059:Apoproteins / Q000097:blood; D001483:Base Sequence; D002784:Cholesterol / Q000097:blood; D008076:Cholesterol, HDL / Q000097:blood*; D008078:Cholesterol, LDL / Q000097:blood; D003920:Diabetes Mellitus / Q000097:blood* / Q000235:genetics / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005260:Female; D005821:Genetic Techniques; D006801:Humans; D006949:Hyperlipidemias / Q000097:blood* / Q000235:genetics / Q000378:metabolism; D008074:Lipoproteins / Q000097:blood* / Q000145:classification; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D010741:Phospholipases A / Q000097:blood / Q000378:metabolism; D054467:Phospholipases A2; D010972:Platelet Activating Factor / Q000378:metabolism; D014280:Triglycerides / Q000097:blood
D000911:Antibodies, Monoclonal; D001059:Apoproteins; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D008074:Lipoproteins; D010972:Platelet Activating Factor; D014280:Triglycerides; D002784:Cholesterol; D010741:Phospholipases A; D054467:Phospholipases A2; D043203:1-Alkyl-2-acetylglycerophosphocholine Esterase