Abstract:Objective This study aimed to explore the possibility of establishing a model of sick sinus syndrome by using miR-5572 transgenic mice. Methods F1 and F2 miR-5572 transgenic mice were bred and genotyped, and then observed the phenotype levels of miR-5572 transgenic mice by morphology, electrocardiogram record (ECG) and the Cav1.2 and Cav1.3 expressions levels of mRNA and protein in sinoatrial node tissue of homozygous, heterozygote and wild type mice.Results Compared with the wild type and heterozygous mice,the miR-5572 homozygous mice showed a development delay and smaller body shape,and had slower average heart rate.The mRNA and protein levels of Cav1.2 and Cav1.3 in the sinoatrial node tissues were significantly lower.Conclusions The results of this study indicate that miR-5572 homozygous mice may be an efficient approach to establish the model of sick sinus syndrome