Objective: To investigate the protective effect of hepatocyte growth factor (HGF) on protein synthesis in rat cardiomyocytes exposed to gamma-ray irradiation.
Methods: Primary cultured cardiomyocytes were irradiated with single-dose (20 Gy) gamma ray in the absence or presence of HGF (40 ng/ml) added in the cell culture 3 h before the exposure. Forty-eight hours after irradiation, the total cellular protein was measured and cell cycle analyzed by flow cytometry. The cardiomyoctes were also infected with AdGFP 48 h after irradiation and the fluorescence intensity of the green fluorescence protein (GFP) in the cells determined by flow cytometry 48 h after infection.
Results: The protein synthesis was decreased significantly in the irradiated cardiomyocytes as compared with the control group (P<0.01), but was remedied significantly by incubation of the cells with HGF before the exposure (P<0.05). Flow cytometry revealed much lower mean fluorescence intensity (MFI) of GFP in irradiated cardiomycytes than in cells without the exposure (P<0.01); The MFI was higher in HGF-treated cardiomyocytes than in cells without HGF treatment following the exposure (P<0.01).
Conclusion: Gamma ray irradiation inhibits protein synthesis in cardiomyocytes, and HGF may attenuate this effect of gamma ray exposure for cardiomyocyte protection.