Bile acid, neutral sterol and faecal fat excretion was studied over a period of 9 weeks in a group of 16 healthy subjects before, during and after administration of fenfluramine. Statistical analysis revealed a significant increase in bile acid excretion during the drug phase (P less than 0.02); and during recovery period of 3 weeks (P less than 0.05). Faecal neutral sterol, as the total of cop...

The action of multidrug efflux pumps in MDR (multidrug resistance) acquisition has been proposed to partially depend on the transport of physiological substrates which may indirectly affect drug partition and transport across cell membranes. In the present study, the PDR18 gene [ORF (open reading frame) YNR070w], encoding a putative PDR (pleiotropic drug resistance) transporter of the ATP-bindi...

The first committed step of sterol biosynthesis is the cyclisation of 2,3-oxidosqualene to form either lanosterol (LA) or cycloartenol (CA). This is catalyzed by an oxidosqualene cyclase (OSC). LA and CA are subsequently converted into various sterols by a series of enzyme reactions. The specificity of the OSC therefore determines the final composition of the end sterols of an organism. Despite...

Fibrates are hypolipidemic drugs that affect the expression of genes involved in lipid metabolism by activating peroxisome proliferator-activated receptors (PPARs). Fibrate treatment causes adverse changes in biliary lipid composition and decreases bile acid excretion, leading to an increased incidence of cholesterol gallstones. In this study, we investigated the effect of fibrates on bile acid...

Using a sterol auxotroph of the LM cell mouse fibroblast, we demonstrate that relatively few cholesterol analogues can substitute for cholesterol as a growth factor. The auxotroph grows normally on desmosterol and trans-22-dehydrocholesterol and at reduced rates on dihydrocholesterol, campesterol, and 22,23-dihydrobrassicasterol. It does not grow with beta-sitosterol, stigmasterol, ergosterol, ...

Following the discovery of ergosterol by Tanret (l), Gerard (2) observed that not only ergot, but fungi in general, contain it. Gerard was the first to recognize ergosterol in yeast, although Nageli (3) had earlier obtained a yeast “cholesterol” in crude form. In traces ergosterol is now known to be widely distributed in both plant and animal kingdoms, but the fungi, and particularly the yeasts...

In vertebrates, the formation of raft lipid microdomains plays an important part in both polarized protein sorting and signal transduction. To establish a system in which raft-dependent processes could be studied genetically, we have analyzed the protein and lipid composition of these microdomains in Drosophila melanogaster. Using mass spectrometry, we identified the phospholipids, sphingolipid...

Membrane potential of aortic endothelial cells under resting conditions is dominated by inward-rectifier K(+) channels belonging to the Kir 2 family. Regulation of endothelial Kir by membrane cholesterol was studied in bovine aortic endothelial cells by altering the sterol composition of the cell membrane. Our results show that enriching the cells with cholesterol decreases the Kir current dens...

Postlarval recruits of mussels Mytilus galloprovincialis were sampled in February 2003 at 7 localities along the Galicia coast (NW Spain) exhibiting different levels of impact from the ‘Prestige’ oil spill. These localities are important grounds for seed collection used in raft culture. The concentrations of polycyclic aromatic hydrocarbons (PAHs) as well as different biochemical and ecophysiol...

Plants have many polarized cell types, but relatively little is known about the mechanisms that establish polarity. The orc mutant was identified originally by defects in root patterning, and positional cloning revealed that the affected gene encodes STEROL METHYLTRANSFERASE1, which is required for the appropriate synthesis and composition of major membrane sterols. smt1(orc) mutants displayed ...