Abstract: Objective: To explore the effects of PKCα/c-fos, Bax/Bcl-2 on the proliferation and apoptosis of rat pulmonary arterial smooth musclecells(PASMCs) in hypoxia. Methods: The PASMCs of rats had been isolated and cultured, and then were cultured under normoxia (5%CO₂、21%O₂、74%N₂)and hypoxia(5%CO₂,2% O₂,93%N₂)condition for 24 h and 48 h, respectively. The proliferation of PASMCs was tested by methylthiazolyltetrazolium (MTT). The changes of PASMCs apoptosis were detected by Annexin V-FITC/PI staining combined flow cytometry. RT-PCR and Western blot analysis were performed to detect the gene and protein levels of PKCα/c-fos, Bax/Bcl-2, respectively. All experiments were repeated three times with at least triplicate samples. Results: The proliferation of PASMCs in hypoxia group were stronger than that of normoxia group after 24 h and 48 h (P < 0.01), while the apoptosis rate did not change significantly. Meanwhile, the higher levels of PKCα, c-fos, Bcl-2 mRNA and proteins after hypoxia for 24 h and 48 h were detected by RT-PCR and Western blot analysis, while the ex-pression levels of Bax had no significant difference under normoxic and hypoxic conditions. Conclusion: Elevated proliferation and expression of PKCα, c-fos, Bcl-2 was observed in rat PASMCs in hypoxia, and while the apoptosis rate had no significant change.

Key words: PKCα/c-fos, Bax/Bcl-2, proliferation, apoptosis, hypoxia