Abstract: Objective To explore the effects of tiotropium on the proliferation of rats’ airway smooth muscle cells by leptin stimulating. Methods ASMCs were derived from rat airway tissue and cultured in vitro. Then ASMCs were treated with leptin (the final concentration 100 μg/L) and tiotropium at different concerntrations (μg/L) (15、30、60 and 120) and cell proliferation was measured by CCK-8 assay. Realtime RT-PCR and Western blot were used to verify the expressions of leptin receptors on ASMCs. Results Leptin could promote the proliferation of ASMCs compared with control group (P<0.05). After treated with tiotropium, leptin’s promotion of the proliferation of ASMCs was inhibited in a dose-dependent manner (P<0.01). After treated with leptin, the expressions of leptin receptor mRNA were increased and the proteins were rose from 0.327±0.011 to 0.541±0.016 （P<0.05）; then treated with different concerntrations of tiotropium, the expressions of leptin receptor mRNA were decreased and the proteins were reduced respectively to 0.514±0.017、0.468±0.025、0.331±0.023 and 0.313±0.017（P<0.05）. The expressions of leptin receptors were positively related to tiotropium concentrations (P<0.01). Conclusion Tiotropium can inhibit the proliferation of rats’ airway smooth muscle cells stimulated by leptin, and its mechanism may be correlated to the decreased the expression of leptin receptors on rats’ ASMCs.

Key words: ［Key word］: tiotropium, leptin, leptin receptor, airway smooth muscle cells, proliferation