We used degenerate primers for the amino-and carboxyl-terminal ends of the rod domains
of intermediate filament proteins in reverse transcriptase-PCR experiments to identify and
clone cytokeratins 8 and 19 (K8 and K19) from cardiac muscle of the adult rat. Northern blots
showed that K8 has a 2.2-kb transcript and K19 has a 1.9-kb transcript in both adult cardiac
and skeletal muscles. Immunolocalization of the cytokeratins in adult cardiac muscle with
isoform-specific antibodies for K8 and K19 showed labeling at Z-lines within the muscle …