Figure 1.
Immunohistochemical localization of sGC isoforms and nNOS in the guinea pig caecum. Panel (A) Distribution of sGCβ1 (green) and Kit (red) in the circular muscle layer and the myenteric plexus region. Intramuscular ICC (ICC-IM) within the circular muscle layer (arrows) and ICC-MY in the myenteric plexus region (arrowheads) showed intense sGCβ1-LI. Myenteric ganglia (G) showed diffuse sGCβ1-LI. Panel (B) A cross-section through the circular muscle layer showing sGCα1-LI (green) and sGCβ1-LI (red) using the TSA method. sGCα1-LI and sGCβ1-LI were detected in cells within the circular layer (arrows) and in the myenteric plexus (G) region (arrowheads). Panels (C) and (D) Whole-mount preparations of the circular muscle layer showing co-localization of sGCβ1 (Panel C, green), sGCα1 (Panel D, green) and Kit in ICC-IM (red). ICC-IM (arrows) ran parallel to the circular muscle fibres and expressed intense sGC-LI. Panel (E) sGCα1-LI (green) and sGCβ1-LI (red) in a whole-mount preparation of the circular muscle layer revealed using the TSA method. sGCα1-LI was co-localized with sGCβ1-LI. Panel (F) A cross-section through the circular muscle layer revealing nNOS-immunopositive nerve fibres (red) and sGCβ1-immunopositive cells (green). Most nNOS nerve fibres were in close apposition to sGCβ1-immunopositive cells (arrows). Myenteric ganglia (G) contained sGCβ1-immunopositive neurons. Panel (G) nNOS-immunopositive nerve terminals (arrowheads) ran in close apposition to sGCβ1-immunopositive cells for more than 100 μm. Scale bars represent 50 μm for panels (A, B and F) and 20 μm for panels (C–E and G).