Histological characteristics of the AV junction at
different levels
Except for the connexins that dominated the electronic conduction of the
heart, as labeled above, three main ion channels (Nav1.5, Cav3.1 and
HCN4) participating in the depolarization of myocardial cells were
immunohistochemically labeled to investigate the conduction ability in
different structures.3,11,12 Figure 5A shows that
Nav1.5 expression was abundant in the atrial and ventricular muscles and
weak in the PB and RN, while Cav3.1 was mainly expressed in the PB and
RN. Figure 5B and C shows that the CN and INE also weakly expressed
Nav1.5 but positively expressed Cav3.1.
Further analysis of Nav1.5 expression via
immunofluorescence microscopy showed that the RN, CN and INE all
presented with significantly lower Nav1.5 expression
(P<0.001). No significant differences in the expression levels
were observed among the RN, CN and INE (P=0.104), but there was a trend
of slightly higher expression of Nav1.5 in the RN than
in the other two regions.