Advanced glycation end products change spontaneous calcium spark morphology in cardiomyocytes

AIM:To investigate the effect of advanced glycation end products (AGEs) on the activity of rynodine receptor (RyR) and calcium regulation in cardiomyocytes, in order to clarify the underlying mechanisms of cardiac dysfunction in diabetic cardiomyopathy. METHODS:The frequency and morphology of spontaneous calcium sparks were observed in cultured neonatal rat ventricular myocytes by the imaging technique of laser scanning confocal microscope. RESULTS:Compared with control group, AGEs increased the frequency of calcium sparks, where 10 mg/L of AGEs increased by 48% (P<0.01), 50 mg/L of AGEs increased by 200% (P<0.01) and 150 mg/L of AGEs increased by 110% (P<0.01). AGEs alter the morphology of spontaneous calcium sparks. AGEs decreased the amplitude and width of calcium sparks, and calcium spark duration. AGEs increased the level of cardiomyocyte resting Ca2+. CONCLUSION: AGEs increases the frequency of spontaneous calcium sparks, thereby enhancing calcium spark-mediated leaking of sarcoplasmic reticulum Ca2+, which may be the cause of diabetic cardiomyopathy systolic dysfunction.