Details

Autor(en) / Beteiligte

• Kujiraoka, Takeshi
• Hattori, Hiroaki
• Ito, Mayumi
• Nanjee, M.Nazeem
• Ishihara, Mitsuaki
• Nagano, Makoto
• Iwasaki, Tadao
• Cooke, C.Justin
• Olszewski, Waldemar L
• Stepanova, Irina P
• Egashira, Tohru
• Miller, Norman E

Titel

Effects of intravenous apolipoprotein A-I/phosphatidylcholine discs on paraoxonase and platelet-activating factor acetylhydrolase in human plasma and tissue fluid

Ist Teil von

• Atherosclerosis, 2004-09, Vol.176 (1), p.57-62

Ort / Verlag

Amsterdam: Elsevier Ireland Ltd

Erscheinungsjahr

2004

Quelle

MEDLINE

Beschreibungen/Notizen

• We have previously shown that intravenous apolipoprotein (apo) A-I/phosphatidylcholine (apo A-I/PC) discs increase plasma high-density lipoprotein (HDL) concentration in humans. We have now studied the associated changes in two enzymes, paraoxonase (PON) and platelet-activating factor acetylhydrolase (PAF-AH) that are carried in whole or in part by HDLs, and are thought to influence atherogenesis by hydrolyzing oxidized phospholipids in lipoproteins. Apo A-I/PC discs (40 mg/kg over 4 h) were infused into eight healthy males. Although plasma apo A-I and HDL cholesterol increased on average by 178 and 158%, respectively, plasma total PON and total PAF-AH concentrations did not rise. By the end of the infusion, HDL-associated PAF-AH had increased by 0.56 ± 0.14 μg/mL (mean ± S.D., P < 0.01), and nonHDL-associated PAF-AH had decreased by 0.84 ± 0.11 μg/mL ( P < 0.05). These changes were accompanied by an increase in the HDL-associated PAF-AH/apo A-I ratio from 0.19 to 0.35 ( P < 0.05), and by a decrease in the nonHDL-associated PAF-AH/apo B ratio from 2.1 to 1.4 ( P < 0.05). No changes in PON or PAF-AH concentrations were detected in prenodal lymph (tissue fluid), collected continuously from the leg. Our results show that the total concentrations of PON and PAF-AH in plasma are uninfluenced by plasma HDL concentration. PAF-AH transfers readily between HDLs and LDLs in vivo, and its distribution between them is determined partly by their relative concentrations and partly by HDL composition.