Imipramine as an alternative to formamide to detubulate rat ventricular cardiomyocytes

T-tubules are membrane invaginations essential for the excitation-contraction coupling (ECC). Imipramine like other cationic amphiphilic drugs, interfere with the PI(4,5)P2 interactions with proteins maintaining the tubular system connected to cell surface. Our main purpose was to validate imipramine as a new detubulating agent in cardiomyocytes. Staining adult rat ventricular myocytes (ARVMs) with di-4-ANEPPS, we showed that unlike formamide, imipramine induces a complete detubulation with no impact on cell viability. Using the patch-clamp technique, we observed a ~40% decrease in cell capacitance after imipramine pretreatment and a reduction of ICa,L Disclaimer: This is a confidential document.