We have examined the lipopolysaccharide (LPS) induced release of interleukin 1 beta (IL-1 beta), IL-6, IL-8 and tumour necrosis factor alpha (TNF-alpha), in EDTA or heparin anticoagulated whole blood, from persons with high or low levels of high density lipoprotein (HDL), incubated at 37 degrees C for up to 20 h, In general, 100 ng LPS/ml gave two to twenty times higher responses than 1 ng LPS/ml, and heparin ten to hundred times higher than EDTA, The release of IL-8 was significantly higher in persons,vith high HDL, and was correlated with HDL, and inversely correlated with triglycerides and sCD14, The release of IL-1 beta, IL-6 and TNF-alpha was correlated with total cholesterol at medium doses of LPS (100 ng/ml), and inversely correlated with lipopolysaccharide-binding protein (LBP) at low doses of LPS (1 ng/ml), Serum levels of LBP were higher in persons with HDL, although not significantly, These results show LPS responsiveness of pro-inflammatory cytokines in whole blood from persons with high and low levels of HDL to be different, presumably of importance in inflammation and atherogenesis. (C) 1996 Academic Press Limited