A, Western blots of membrane proteins prepared from dog atrium (lane 1, DA1) and isolated dog atrial myocytes (lane 2, DA2) probed with a Kv3.1 antibody. Lane 3, dog atrial membrane preparation after pre-incubation of antibody with Kv3.1 peptide (Pre-inc). B, Western blots with Kv1.5 antibody obtained with human atrial (HA) and dog atrial (DA) tissues.