title: Binary phase behavior of angiotoxic oxidized cholesterols with cholesterol.
abstract: Binary phase diagrams of oxidized cholesterols with cholesterol were constructed in order to find a possible physical mechanism for these cytotoxic sterols as disruptors of cell membranes. Two compounds, 25-hydroxycholesterol and 7-ketocholesterol, behave similarly in solids with cholesterol, i.e., continuous solubility can be demonstrated over all concentrations with some tendency for individual molecular species to cluster in the liquid state. However, the two compounds have greatly different solubilities in phospholipid bilayers. The interaction of cholesterol with cholestane 3 beta, 5 alpha,6 beta-triol differs from that of the other two binaries since these molecules form a eutectic. This compound has been found to be soluble in phospholipid bilayers. Hence, from available evidence, the three oxidized cholesterols must employ different mechanisms for disruption of cell membranes, depending on which membrane component can most easily solubilize each.
authors.affiliation: Medical Foundation of Buffalo, Inc., NY 14203.
authors.forename: D L
authors.initials: DL
authors.lastname: Dorset
mesh_terms: D002152:Calorimetry, Differential Scanning; D002777:Cholestanols / Q000737:chemistry*; D002784:Cholesterol / Q000737:chemistry*; D006888:Hydroxycholesterols / Q000737:chemistry*; D000960:Hypolipidemic Agents / Q000737:chemistry*; D007653:Ketocholesterols / Q000737:chemistry*; D007700:Kinetics; D008433:Mathematics; D014961:X-Ray Diffraction
chemical_list: D002777:Cholestanols; D006888:Hydroxycholesterols; D000960:Hypolipidemic Agents; D007653:Ketocholesterols; C000474:cholestane-3,5,6-triol; C007997:25-hydroxycholesterol; D002784:Cholesterol; C003001:7-ketocholesterol