Aim To investigate the condition of very low density lipoprotein (VLDL) receptor mRNA expression by smooth muscle cells (SMC).Methods Rabbit aortic SMC was cultured by digestion method. Total RNA from cultured SMC with or without interleukin-1β) (lL-13β) was extracted by the acidguanldinium thiocyanate-phenol-chloroform method. followed by mRNA isolation using an oligo (dT)-cellulose column. The expression of specific VLDL receptor mRNA in SMC was determined by Northern blot analysis.Results The VLDL receptor mRNA in cultured rabbit aortic SMC can be detected by Northern blot analysis. After cultured SMC exposure to 1 μg/L of lL, 1β for 15 h, the level of specific VLDL receptor mRNA increased by two fold as much as unstimulated cells.Conclusion Cultured rabbit aortic SMC was able to express VLDL receptor mRNA, and IL-1β could up-regulate the expression of VLDL, receptor mRNA in the cultured SMC. It suggested that SMC might take in lipoproteins through VLDL, receptor, and so became foam cells. IL-1β might be concerned with pathogen-esis of atherosclerosis by its effect on SMC VLDL re-ceptor mRNA expression.