PLATELET-AGGREGATION INHIBITING AND ANTICOAGULANT EFFECTS OF OLIGOAMINES .25. INTERACTIONS OF THE OLIGOAMINE RE-1492 WITH BIOMEMBRANES

The absorption of D-glucose by rat thymocytes is reduced to half of co ntrol by 30 mu mol/L and decreased to 10% by 100 mu mol/L of RE 1492. This is backed by the fact that the absorption of 2-deoxy-D-glucose is inhibited in the same extent. The more hydrophilic oligoamine RE 1888 had an analogous but smaller effect while spermine was ineffective, I n a lipid peroxidation model RE 1492 or spermine in a concentration of 100 mu mol/L nearly completely inhibited for formation of Fe3+ ions w hen the phospholipid was mimicked by adenosine monophosphate. This sug gests an interaction with negatively charged membrane phospholipids. R E 1888 had an equal but smaller effect. The effect of RE 1492 on lipid order and lipid motility was checked on ovine lymphocyte membranes by fluorescence polarization measurements. The steady state as well as t he limiting anisotropy as an expression for lipid order is decreased b y rising concentrations of RE 1492. The use of several anthroyloxy ste aric acids as fluorescent probes also shows an increased lipid motilit y in several areas of the membrane bilayer. The use of fluorescent par inaric acids suggests that areas of high regularity, i.e. liquid cryst al formation are involved, too.