The role of oxidative stress in high glucose-induced apoptosis in neonatal rat cardiomyocytes.

Accumulating evidence has demonstrated that apoptosis plays a critical role in the pathogenesis of diabetic cardiomyopathy. However, the exact molecular mechanisms by which hyperglycaemia induces cardiomyocyte apoptosis are not fully understood. The present study was designed to investigate the role of oxidative stress in high glucose-induced apoptosis in cultured neonatal rat cardiomyocytes. The MTT assay was used to detect the viability of cardiomyocytes exposed to different concentrations of glucose. Oxidative stress was evaluated by measuring intracellular reactive oxygen species with 2',7'-dichlorofluoresce diacetate staining and by detecting malondialdehyde and superoxide dismutase in the supernatant of culture media. Cardiomyocyte apoptosis was determined by flow cytometry and confocal laser scanning microscopy with Annexin V/PI staining. Our results showed that high glucose can induce oxidative stress and promote apoptosis in neonatal rat cardiomyocytes and the antioxidant can protect against high glucose-induced apoptosis, which suggests that oxidative stress is involved in high glucose-induced cardiomyocyte apoptosis. Furthermore, caspase-3 was found to be activated in the process of high glucose-induced oxidative stress, which subsequently contributes to increased apoptosis in neonatal rat cardiomyocytes. In conclusion, our study demonstrates that oxidative stress is involved in high glucose-induced cardiomyocyte apoptosis via activation of caspase-3.