[Expression of L-type calcium channel alpha1C subunit in adult rat heart].

Objective: To investigate the expression and distribution of L-type calcium channel alpha1C subunits in adult rat heart.

Methods: HE staining was applied on the frozen sections of adult rat heart to identify the sinoatrial node (SAN), atrioventricular node (AVN), and posterior nodal extension (PNE). The protein expression of L-type calcium channel alpha1C in adult rat heart and its cellular localization were examined by Western blotting and immunohistochemistry, respectively.

Results: L-type calcium channel alpha1C subunit was immunolocalized on the membrane of the myocardial cells, and its expression increased gradually in the SAN, AVN, PNE, right atrium and right ventricle. The protein level of L-type calcium channel alpha1C in the AVN was similar to that in the PNE (P>0.05), and its level in the right atrium and ventricle were significantly higher than those in the SAN and AVN (P<0.01). The results of Western blotting were well consistent with the results of immunohistochemistry.

Conclusion: The expression of L-type calcium channel alpha1C subunit may play a role in the electrophysiological functions of the heart.