Immunolocalization of CAR to intercalated discs in human and murine cardiac muscle. Human [A, B] and murine [C, D] cardiac muscle sections were reacted with the polyclonal anti-C-terminal antibodies RP194 [A, C] and RP291 [B, D]. Note the intense staining of both isoforms at the human intercalated discs (arrow) [A, B] and murine intercalated discs [C, D]. Neither the human cardiac tissue [E] nor the murine cardiac muscle [F] gave any signal when incubated with the anti-rabbit IgG. Bar = 10 μm (A, E); 30 μm (C, F).