Neonatal rat ventricular cardiomyocyte isolation

All rats were purchased and raised in the Experimental Animal Center of Nanjing Medical University (Nanjing, China). All procedures with rats were in accordance with guidelines on the use and care of laboratory animals for biomedical research published by the National Institutes of Health (No. 85-23, revised 1996), and the experimental protocol was reviewed and approved by the Animal Care and Use Committee of Nanjing Medical University. Primary neonatal rat ventricular cardiomyocytes (NRVMs) using ventricles from day 0 (P0) and day 10 (P10) of neonatal pups were prepared as previously described¹⁸ and purified by Percoll gradient centrifugation.