Estrogen treatment raises plasma high density lipoprotein (HDL) levels, which may reduce cardiovascular risk. To identify the responsible mechanisms as well as the importance of the route of administration, we treated eight healthy postmenopausal women in a double-blind crossover study with three treatments for 6 weeks each: oral estradiol, 2 mg daily; transdermal estradiol, 0.1 mg twice weekly...

In human serum, polymorphism of apoA-II predominantly in HDL3 could be demonstrated. HDL3-apoA-II was composed of four isoproteins, each with a molecular weight of 8600 (reduced form) and identical immunological properties. The isoproteins are designated apoA-II-1 (pI 5.16), apoA-II-2 (pI 4.89) corresponding to the already known apoA-II monomer band, apoA-II-3 (pI 4.58), and apoA-II-4 (pI 4.31)...

Although the partitioning of apolipoprotein A-I (apoA-I) molecules in plasma between high-density lipoprotein (HDL)-bound and -unbound states is an integral part of HDL metabolism, the factors that control binding of apoA-I to HDL particles are poorly understood. To address this gap in knowledge, we investigated how the properties of the apoA-I tertiary structure domains and surface characteris...

Incubation of phosphatidylcholine vesicles with isolated high density lipoproteins (HDL) or with whole plasma results in transfer of phospholipid into HDL. To investigate the mechanisms of this process, small unilamellar vesicles of egg phosphatidylcholine were incubated with human HDL3 (d 1.125 to 1.210 g/ml) or with plasma and were subsequently analyzed by density gradient ultracentrifugation...

A portion of this work has appeared in abstract form (1). Received for publication 17 August 1978 and in revised form 27 December 1978. 858 became 49 and 51% in HDL2 and HDL3, respectively. ApoA-II was found mainly in HDL3, both before and during nicotinic acid treatment. Administration of the drug caused a 14% reduction in its plasma concentration (P < 0.05), which derived principally from a f...

The objective of the present study was to examine the impact of the T111I missense mutation in exon 3 of the endothelial lipase (EL) gene on HDL and its potential interaction effect with dietary fat. The study sample included 281 women and 216 men aged between 17 and 76 years from the Québec Family Study. Plasma HDL3-C levels of I111I homozygote women were higher compared with those of women ca...

Diet-induced changes in high density lipoprotein (HDL) density and size were studied in patas monkeys. When the animals were switched from a moderate fat-low cholesterol diet to a high fat-high cholesterol (HFHC) diet, the plasma apoA-I levels increased initially in all of the animals. The apoA-I levels remained elevated in monkeys able to maintain their plasma cholesterol concentrations near b...

1. Phospholipid transfer protein (PLTP) mediates conversion of high-density lipoprotein (HDL3) to large particles, with concomitant release of apolipoprotein A-I (apoA-I). To study the mechanisms involved in this conversion, reconstituted HDL (rHDL) particles containing either fluorescent pyrenylacyl cholesterol ester (PyrCE) in their core (PyrCE-rHDL) or pyrenylacyl phosphatidylcholine (PysPC)...

OBJECTIVE Pioglitazone, an antihyperglycemic drug, increases plasma high-density lipoprotein (HDL)-cholesterol in patients with type 2 diabetes. The mechanisms by which pioglitazone regulate HDL levels are not clear. This study examined the effect of pioglitazone on hepatocyte apolipoprotein AI (apoA-I) and apoA-II production and HDL-protein/cholesterol ester uptake. METHODS AND RESULTS In hu...

A 7-yr-old girl with high density lipoprotein (HDL) deficiency and xanthomas has been identified in a Turkish kindred with repetitive consanguinity. She has severely reduced HDL-cholesterol and no apolipoprotein (apo) A-I. ApoA-II is reduced, whereas apoA-IV and apoC-III are normal. ApoB and low density lipoprotein (LDL)-cholesterol are increased. This is reflected in hypercholesterolemia. VLDL...