Abstract： Objective:To investigate the effect of Fasudil on autophagy and apoptosis of aortic smooth muscle cells (VSMC) and its relationship with phosphatidylinositol 3 kinase (PI3K) -protein kinase B (Akt) -mammalian target of rapamycin (mTOR) signaling pathway.Methods:The VSMC of SD rat were cultured with 10% fetal bovine serum and DMEM medium, and the expression of α smooth muscle actin (a-SMA) was detected by immunocytochemical staining to identify VSMC. Platelet derived growth factor (PDGF) was used to induce VSMC, and PDGF-induced VSMC were divided into blank group, control group, Fasudil group (30 μmol/L Fasudil) and Fasudil+LY294002 group (30 μmol/L Fasudil+25 μmol/L LY294002) . MTT assay was used to detect the cell proliferation, flow cytometry was used to detect the apoptosis rate and apoptosis cycle, and GFP-mRFP-LC3 double fluorescence was used to detect the level of autophagy. Western blotting (WB) was used to detect the protein expressions of Bax, Bcl-2, LC3, Beclin-1, PI3K, Akt, p-Akt, mTOR and p-mTOR, and the results were compared and analyzed.Results:Under microscope, the cultured cells showed long spindle-shaped, radioactive growth and typical "peak-valley" -like structure. The positive expression rate of a-SMA was 99%, which confirmed that the cultured cells were high-purity aortic VSMC. The results of MTT experiment showed that the cell proliferation capacity of Fasudil group was significantly lower than that of control group ( P<0.05) , and that of Fasudil +LY294002 group was higher than that of Fasudil group ( P<0.05) . Flow cytometry showed that compared with the control group, the apoptosis rate and the proportion of G 0-G 1 phase cells in Fasudil group were increased (both P<0.05) . Compared with the Fasudil group, the apoptosis rate and the proportion of G 0-G 1 phase cells in the Fasudil + LY294002 group were reduced (both P<0.05) . GFP-mRFP-LC3 double fluorescence detection results showed that compared with control group, autophagy was enhanced in Fasudil group ( P<0.05) . Compared with the Fasudil group, autophagy was decreased in the Fasudil+LY294002 group ( P<0.05) . WB detection results showed that compared with the control group, the levels of Bax、Bcl-2, LC3-Ⅱ/LC3-Ⅰ, Beclin1 and the phosphorylation levels of PI3K, Akt and mTOR were increased (all P<0.05) . Compared with Fasudil group, the levels of Bax、Bcl-2, LC3-Ⅱ/LC3-Ⅰ, Beclin1 and the phosphorylation levels of PI3K, Akt and mTOR in Fasudil+LY294002 group decreased (all P<0.05) . Conclusions:Fasudil can inhibit VSMC proliferation, promote autophagy and apoptosis, and improve vascular function by activating PI3K-Akt-mTOR signaling pathway.