The aim of this study was to determine the effect of ethanol (EtOH) on endothelial monocyte chemotactic protein-1 (MCP-1) expression. Interleukin-1 (IL-1) increased the production of MCP-1 by human umbilical vein endothelial cells (HUVEC) from undetectable levels to approximately 900 pg/ml at 24 h. EtOH dose-dependently inhibited IL-1-stimulated MCP-1 secretion as determined by ELISA; 25±1%, 35±7% and 65±5% inhibition for 1, 10 and 100 mM EtOH, respectively, concomitant with inhibition of monocyte adhesion to activated endothelial cells. Similarly, EtOH dose-dependently inhibited IL-1-stimulated MCP-1 mRNA expression. Experiments with actinomycin D demonstrated that EtOH decreased the stability of MCP-1 mRNA. In addition, EtOH significantly reduced NF-B and AP-1 binding activity induced by IL-1, and inhibited MCP-1 gene transcription. Binding of ¹²⁵I-MCP-1 to its receptor (CCR2) on THP-1 human monocytic cells was not affected by EtOH treatment. Modulation of the expression of MCP-1 represents a mechanism whereby ethanol could inhibit atherogenesis by blocking the crucial early step of monocyte adhesion and subsequent recruitment to the subendothelial space. These actions of ethanol may underlie, in part, its cardiovascular protective effects in vivo.