Mowri H O, Patsch J R, Ritsch A, Föger B, Brown S, Patsch W
Department of Medicine, Baylor College of Medicine, Houston, TX 77030.
J Lipid Res. 1994 Feb;35(2):291-300.
To gain insight into metabolic determinants of high density lipoproteins (HDL) containing apolipoproteins A-I and A-II (LpA-I/A-II) and those containing A-I, but devoid of A-II (LpA-I), the plasma concentration of LpA-I and LpA-I/A-II within the HDL2 and HDL3 density spectrum was measured in 14 normolipidemic male subjects on a standardized diet. Apolipoprotein plasma concentrations of HDL subspecies were compared with the magnitude of postprandial lipemia, activities of lipoprotein lipase and hepatic lipase in postheparin plasma, plasma lecithin:cholesterol acyltransferase (LCAT) activity, and cholesteryl ester transfer protein (CETP) mass. Plasma levels of LpA-I/A-II were 2.5 times higher than levels of LpA-I (123 +/- 20 vs. 48.3 +/- 22.1 mg protein/dl) and the partition of LpA-I and LpA-I/A-II between HDL2 and HDL3 differed in that the proportion of LpA-I associated with HDL2 was greater than that of LpA-I/A-II (23 +/- 19 vs. 6 +/- 6%, P < 0.002). With increasing levels of HDL2, the proportion of LpA-I in HDL2 increased (P < 0.002). Furthermore, levels of LpA-I and LpA-I/A-II were strongly correlated within the HDL2 but not within the HDL3 density region. Plasma levels of LpA-I, but not LpA-I/A-II, were inversely correlated with the magnitude of postprandial lipemia. However, activities of lipoprotein lipase and hepatic lipase tended to show stronger associations with the partition of LpA-I/A-II between HDL2 and HDL3 than with that of LpA-I. Within the HDL3, but not the HDL2 density spectrum, LpA-I/A-II exhibited a positive association with plasma LCAT activity, while LpA-I displayed an inverse association with plasma CETP mass. These results are consistent with differences in substrate properties of LpA-I and LpA-I/A-II for lipoprotein modifying enzymes and imply different, but overlapping metabolic pathways of LpA-I and LpA-I/A-II.
为深入了解含载脂蛋白A-I和A-II的高密度脂蛋白（HDL）（LpA-I/A-II）以及含A-I但不含A-II的HDL（LpA-I）的代谢决定因素，我们对14名血脂正常的男性受试者进行标准化饮食，测量了HDL2和HDL3密度范围内LpA-I和LpA-I/A-II的血浆浓度。将HDL亚类的载脂蛋白血浆浓度与餐后血脂水平、肝素后血浆中脂蛋白脂肪酶和肝脂肪酶的活性、血浆卵磷脂胆固醇酰基转移酶（LCAT）活性以及胆固醇酯转移蛋白（CETP）质量进行比较。LpA-I/A-II的血浆水平比LpA-I的水平高2.5倍（分别为123±20和48.3±22.1mg蛋白/dl），并且LpA-I和LpA-I/A-II在HDL2和HDL3之间的分布不同，即与HDL2相关的LpA-I比例大于LpA-I/A-II（分别为23±19%和6±6%，P<0.002）。随着HDL2水平升高，HDL2中LpA-I的比例增加（P<0.002）。此外，LpA-I和LpA-I/A-II的水平在HDL2密度区域内呈强相关，但在HDL3密度区域内无相关性。LpA-I的血浆水平而非LpA-I/A-II的血浆水平与餐后血脂水平呈负相关。然而，脂蛋白脂肪酶和肝脂肪酶的活性与LpA-I/A-II在HDL2和HDL3之间的分布的相关性，似乎比与LpA-I的分布的相关性更强。在HDL3密度范围内而非HDL2密度范围内，LpA-I/A-II与血浆LCAT活性呈正相关，而LpA-I与血浆CETP质量呈负相关。这些结果与LpA-I和LpA-I/A-II作为脂蛋白修饰酶的底物特性差异一致，并暗示LpA-I和LpA-I/A-II的代谢途径不同但有重叠。
