Primary culture and identification of sinoatrial node cells from newborn rat

Objective To establish a reliable approach to primary culture and identification of sinoatrial node (SAN) cells. Methods The SAN cells were cultured from SAN tissue removed from neonatal Wistar rats and purified with differential attachment and 5'-bromodeoxyuridine (BrdU) treatment. The obtained cells were morphologically observed with inverted microscopy and transmission electron microscopy. Its action potential was recorded using electrophysiological methods. Results Three distinctly different cells were observed in the cultured SAN cells: spindle, triangle and irregular. Of these, the spindle cells comprised the greatest proportion, with their shape, structure and electrophysiological characteristics consistent with those of the pacemaker cells of SAN. The triangle cells were similar in features to the similarly shaped myocytes located in the atrial myocardium. Conclusions The culture method of differential attachment combined with BrdU treatment is a reliable approach to growing SAN cells. Of the cells cultured from SAN, the spindle cells appear to function as pacemaker cells.