BETA-BLOCKERS INHIBIT THE MODIFICATION OF LOW-DENSITY LIPOPROTEINS BYSODIUM-HYPOCHLORITE IN-VITRO

The effect of beta-blockers (alprenolol, oxprenolol, atenolol, acebuto lol) and the non-steroidal anti-inflammatory drug, diclofenac, on modi fication of low-density lipoproteins (LDL) by sodium hypochlorite (NaO Cl) was investigated in vitro. Beta-blockers and diclofenac inhibit th e formation of thiobarbituric acid reactive substances in LDL modified by NaOCl. Beta-blockers, but not diclofenac, inhibit the hypochlorite -induced aggregation of LDL which was determined by photon correlation spectroscopy. The intracellular accumulation of cholesterol esters in J774 macrophages is inhibited by addition of beta-blockers, but not d iclofenac, to LDL prior to the addition of NaOCl. The modification inh ibiting effect of beta-blockers is inversely correlated to the binding capabilities of these substances to LDL which were assessed by laser electrophoresis. Inhibition of LDL modification in vivo by beta-blocke rs may reduce the risk of atherosclerosis and, therefore, compensate f or the cholesterol-raising effect of these drugs in human plasma. Copy right (C) 1997 Elsevier Science Ireland Ltd.