Nonspecific lipid transfer protein accelerated cholesterol exchange from brush border vesicles according to a biphasic time course, but sonicated vesicles made from brush border phospholipids and glycosphingolipids showed a single phase exchange. Removal of surface protein with papain or opening brush border vesicles with deoxycholate did not abolish the biphasic exchange pattern. In brush bord...

Cholesterol-laden, human monocyte-derived macrophages were found to contain 27-hydroxycholesterol in proportion to their content of cholesterol ester. In accordance with previous work with human lung alveolar macrophages, there was a significant efflux of 27-hydroxycholesterol and 3beta-hydroxy-5-cholestenoic acid from the cultured cells. The efflux of 27-hydroxycholesterol was proportional to ...

It has been shown that vesicles play a key role in the onset mechanism of aortic calcification related to cholesterol-induced atherosclerosis. This study using a rabbit model was conducted to determine whether cholesterol exerts a direct effect on vesicle's calcifiability. Inclusion of cholesterol in calcifying media stimulated ATP-initiated deposition of calcium in a dose-dependent manner by v...

A concept and its experimental realization in a collaborative study are presented which permit the highly selective removal of any blood plasma component from endogenous or exogenous sources, provided they have antigenic or haptenic properties. Our primary goal was the selective removal of low density serum lipoprotein which would lead to the reduction of plasma cholesterol, an event most desir...

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Certain steroids having an oxo group at the C-17 or C-20 position such as pregnenolone and dehydroisoandrosterone inhibit the cholesterol transport from lysosomes to other cellular sites. Taking advantage of the fact that the inhibition is reversed upon removal of the steroids, we studied the factors that control the cholesterol transport from lysosomes to other cellular sites in macrophages. M...

Human gallbladders with cholesterol stones exhibit impaired muscle contraction induced by agonists that act on transmembrane receptors, increased membrane cholesterol content, and abnormal cholesterol-to-phospholipid ratio compared with those with pigment stones. The present study was designed to investigate the functions of the CCK receptor of gallbladder muscle membranes by radioreceptor assa...

The 7 alpha-hydroxylation of two cholesterol analogues, sitosterol and cholestanol, and their effect on the 7 alpha-hydroxylation of cholesterol were measured in rat and human hepatic microsomes. In untreated rat liver microsomes, the 7 alpha-hydroxylation of cholesterol was higher than that of cholestanol (1.4-fold) and sitosterol (30-fold). After removal of endogenous sterols from the microso...