The expression of heme oxygenase-1 in vascular smooth muscle cells induced by lipopolysaccharide

AIM:To study the alterations of heme oxygenase-1 mRNA in vascular smooth muscle cells(VSMC) induced by lipopolysaccharide(LPS) and the role of heme oxygenase(HO)/carbon monoxide(CO)pathway in the disorders of regulation of cardiovascular system by LPS. METHODS: LPS (final concentrations 10 mg/L,30 mg/L and 50 mg/L) was added in cultured VSMCs for 6 h respectively or 10 mg/L LPS for 9 h and 18 h. MDA content, LDH release and the rate of trypan blue uptake of VSMC were measured. HO-1 mRNA expression was examined by Northern Blot. RESULTS:VSMC HO-1 mRNA expression was increased gradually with the increasing of LPS concentration. When final concentration of LPS was 50 mg/L, the HO-1 mRNA expression of VSMC was increased by 176.7% compared with control. When LPS final concentration was 10 mg/L, the HO-1 mRNA expression increased gradually along with the culture time. When cultured for 18 h, the HO-1 mRNA expression of VSMC was increased by 195.6% compared with control. Only at LPS 50 mg/L for 6 h and 10 mg/L for 18 h, the rate of trypan blue uptake,MDA content and LDH release were significantly increased. CONCLUSION: LPS can induce the HO-1 mRNA expression of VSMC and that were dose-dependent and time-dependent. The inducible HO may play an important role in the pathogenesis of vascular system under LPS.