The effect of dimiristoylphosphatidylethanol on the rotational mobility of n-(9-Anthroyloxy) stearic acid in neuronal and model membranes

The aim of this study was to provide a basis for examining the molecular mechanism for the pharmacological action of ethanol. We studied di¬myristoyl¬phosphatidylethanol (DMPEt)’s effects on specific locations of n-(9-anthroyloxy) palmitic acid or stearic acid (n-AS) within phos¬pholipids of synaptosomal plasma membrane vesicles isolated from bovine cerebral cortex (SPMV) and liposomes of total lipids (SPMVTL) and phospholipids (SPMVPL) extracted from SPMV. DMPEt increased rotational mobility (increased disordering) of hydrocarbon interior, but it decreased mobility (increased ordering) of membrane interface, in native and model membranes. The degree of rotational mobility in accordance with the carbon atom numbers of phospholipids comprising neuronal membranes was in the order at the 16, 12, 9, 6 and 2 position of aliphatic chain present in phospholipids. The sensitivity of increasing or decreasing effect of rotational mobility of hydrocarbon interior or surface region by DMPEt differed depending on the neuronal and model membranes in the descending order of SPMV, SPMVPL and SPMVTL.