Abstract: Objective To study the changes of intracellular Ca2+ concentration and transient receptor potential channels 1 and 6(TRPC1,TPRC6)mRNA expression in rat airway smooth muscle cells (ASMC) after nicotine intervention.Methods Various concentrations of nicotine(10 μg/L,20 μg,L,50μg/L,100μg/L)were used to stimulate rat airway smooth muscle cells.The intracellular Ca2+ concentrations after nicotine intervention for 24 and 48 hours were measured by Incyte system.The total RNA was extracted from rat ASMC.and reversely transcribed into cDNA.The real-time PCR method was used to analyze the changes in TRPC1 and TRPC6 mRNA expression.Results The groups treated with different concentrations of nicotine(20 μg/L,50μg/L,100 μg/L)for 24 or 48 hours showed increases in intracellular Ca2+concentration when compared with control[(117.99±19.39),(122.89±17.91),(124.70±17.93)nmol/L vs (85.85±12.60)nmol/L;(142.07±18.99),(162.27±19.91),(207.30±26.56)nmol/L vs(98.04±2.39)nmol/L;P<0.05].In addition,relative expressions of TRPC1 and TPRC6 mRNA in rat ASMC also increased significantly compared with controls(P<0.05).The levels of intracellular Ca2+ concentration and TRPC6mRNA were significantly higher with 48 h nicotine(100 μg/L,L)intervention than as found with 24 h nicotineintervention.Conclusion Nicotine may increase the intracellular Ca2+ concentration by up-regulating the expression of TRPC1 and TPRC6 in rat ASMC.