CONCENTRATIONS OF APOLIPOPROTEIN-AI, APOLIPOPROTEIN-AII, AND APOLIPOPROTEIN-E IN PLASMA AND LIPOPROTEIN FRACTIONS OF ALCOHOLIC PATIENTS - GENDER DIFFERENCES IN THE EFFECTS OF ALCOHOL

Previous studies have shown that plasma levels of high-density lipoprotein (HDL) cholesterol and the two major protein components of HDLs, i.e., apolipoproteins AI and AII, were elevated in male alcoholic patients without serious liver injury. By contrast, alcohol effect on apolipoprotein E remains unclear. Apolipoprotein E is a major component of very low-density Lipoprotein (VLDL) and a minor component of human high-density Lipoprotein. It plays a critical role in Lipoprotein metabolism through cellular Lipoprotein receptors. Furthermore, previous works were carried out mostly with male subjects, whereas alcohol effects on serum apolipoproteins in female subjects have not yet been adequately addressed. In this study, we have raised antibodies specifically to recognize human apolipoprotein AI, AII, and E, respectively, to quantify apolipoprotein concentrations in plasma and lipoprotein fractions of male and female alcoholic patients. We have also measured plasma apolipoprotein concentrations in patients who had abstained from alcohol while in the hospital. Our results showed the following: (1) plasma concentrations of apolipoprotein Al and AII were significantly elevated yet plasma apolipoprotein E decreased (33%) significantly (P < .01) in male alcoholic patients; (2) apolipoprotein Al concentrations in female nondrinking control subjects were higher than in male controls, and the concentrations of apolipoprotein AI in female alcoholic patients were not significantly elevated over those of female controls; (3) similar to their male counterparts, female alcoholic patients exhibited higher plasma apolipoprotein AII and lower apolipoprotein E; (4) changes in plasma apolipoproteins seen here were most Likely attributable to a direct effect of alcohol but not a secondary effect of mild liver injury; (5) changes in plasma apolipoprotein levels in alcoholic patients were reversible in 1 week after alcohol abstinence; and (6) the decrease of plasma apo E in alcoholic patients was indicated by the presence of apo E-deficient VLDL particles whereas the concentration of apo E in HDL particles of alcoholic patients remained unaffected.