The phospholipase C-mediated hydrolysis of phosphatidylcholine has been shown recently to be activated by a number of agonists. Muscarinic receptors, which trigger various signal transduction mechanisms including inhibition of adenylate cyclase through Gi, have been shown to be potent stimulants of this novel phospholipid degradative pathway. We demonstrate here, by exogenous addition of Bacill...

The binding of phosphatidylcholine and cholesterol in model bile to human gallbladder mucin was studied by means of a rapid filtration binding assay and sucrose density gradient ultracentrifugation. Numerous low affinity binding sites for phosphatidylcholine and cholesterol were present on gallbladder mucin. Binding of phosphatidylcholine and cholesterol to mucin increased as a function of chol...

The rate of removal of phosphatidylethanolamine and phosphatidylcholine from the plasma of rats treated with antiserum to hepatic lipase was measured. The hepatic lipase antiserum was injected intravenously into animals prior to injection of 32P-labeled chylomicrons or 32P-labeled high density lipoproteins. In experiments in which 32P-labeled chylomicrons were injected, antiserum treatment inhi...

The present study was performed to determine whether the degree of lecithin hydrophobicity regulates bile metastability and, therefore, affects the process of cholesterol crystallization. Supersaturated model bile (MB) solutions were prepared with an identical composition on a molar basis (taurocholate/lecithin/cholesterol, 73:19.5:7.5; total lipid concentration 9 g/dl) except for the lecithin ...

A double-blind controlled study was undertaken to examine the value of phosphatidylcholine as a treatment for tardive dyskinesia (TD) in 19 psychiatric patients. All patients were maintained on their usual psychotropic medication throughout the entire study. In addition, they were given either phosphatidylcholine (30 g/day) or placebo for 6 weeks. Thirteen of the patients received the crossover...

Hepatocytes obtained from rats fed a choline-deficient diet for 3 days were cultured in a medium +/- choline (100 microM) or methionine (200 microM). We investigated how choline deficiency affected hepatic lipogenesis, apolipoprotein synthesis, and lipoprotein secretion. The mass of triacylglycerol and phosphatidylcholine secreted was increased about 3-fold and 2-fold, respectively, by the addi...

BACKGROUND Alterations in surfactant phospholipid compositions are a recognized feature of many acute and chronic lung diseases. Investigation of underlying mechanisms requires assessment of surfactant phospholipid molecular composition and kinetics of synthesis and turnover. Such studies have recently become possible in humans due to the development of stable isotope labelling combined with ad...

The ferric-xylenol orange (FOX) method for measurement of hydroperoxides is based on a technique that employs reduction of peroxides in an acidic condition by Fe2+ and formation of the colored ferric-xylenol orange (XO/Fe3+) product with a peak at 560 nm. The 560 nm absorbance peak of XO/Fe3+ shifts to a 610 nm peak with high absorption intensity in the presence of phosphatidylcholine. This is ...

Incubation of intact Sendai virions or reconstituted Sendai virus envelopes with phosphatidylcholine/cholesterol liposomes at 37 degrees C results in virus-liposome fusion. Neither the liposome nor the virus content was released from the fusion product, indicating a nonleaky fusion process. Only liposomes possessing virus receptors, namely sialoglycolipids or sialoglycoproteins, became leaky up...

1. The interaction of cholesterol with equimolar mixtures of 18 : l e /18 : I c phosphatidylethanolamine and 16 : 0/16 : 0 phosphatidylcholine has been investigated employing differential scanning calorimetry and 3,p NMR. At temperatures where lateral phase separation occurs cholesterol interacts preferentially with the (gel state) 1 6 : 0 / 1 6 : 0 phosphatidylcholine component , in agreement ...