Doxazosin, an alpha(1)-adrenergic antihypertensive agent, decreases serum oxidized LDL

Oxidized low-density lipoprotein (ox-LDL) is well known to play an importan t role in atherogenesis through the recruitment of monocytes into vessel wa lls and the deposition of cholesterol ester in the macrophages, which leads to the formation of lipid-rich plaque. It was assumed that only trace amou nts of ox-LDL were present in plasma because the half-life of ox-LDL was on ly a few minutes. Recently, through the use of a monoclonal antibody agains t ox-LDL, a quantitative method to measure serum ox-LDL concentration has b een developed. Metabolites of doxazosin, an alpha (1)-adrenergic antihypert ensive agent, have been reported to inhibit oxidation of LDL in vitro. In t his study, we investigated the in vivo effect of doxazosin on LDL oxidation using this new method to measure serum ox-LDL concentration. After the adm inistration of doxazosin for 1 to 2 months, serum concentration of ox-LDL d ecreased significantly (P < .05). Although the reduction of ox-LDL concentr ation does not strictly indicate doxazosin's antiatherosclerotic effect, it may constitute one of doxazosin's additional weapons beside lowering blood pressure and serum lipid values in the prevention of atherosclerosis. (C) 2001 American Journal of Hypertension, Ltd.