Figure 8. Distribution of Kit immunoreactivity and Cx43 immunoreactivity in muscular wall of the gastric antrum.

A, B and C, a Z-stack of a transverse cryosections of the guinea-pig antrum immunostained for the Kit receptor, Cx43 and a merged image of A and B, respectively. A, immunopositive deposits in the myenteric region in ICC_my and on ICC_IM within the circular smooth muscle layer. A few deposits are also found in the longitudinal muscle layer (LM). B, Cx43 staining in the circular smooth muscle layer and on both ICC_my and ICC_IM. The Cx43 immunostaining appears as dots arranged in lines along the surface of the longitudinally sectioned circular smooth muscle cells (CM). No Cx43 staining was apparent in the longitudinal smooth muscle layer except in regions where Kit immunoreactivity was detected. C, regions of colocalization of Kit with Cx43 are labelled yellow. Scale bar = 10 μm. D, E and F, a Z-stack of an isolated ICC_IM in the surrounding circular muscle immunostained for Kit, Cx43 and a merged image of D and E, respectively. Note that the density of Cx43 immunostaining is significantly greater on the ICC_IM compared with the circular smooth muscle (E and F). Scale bar = 50 μm. G, H and I, high-power images of a Z-stack illustrating a layer of ICC_my and adjacent circular smooth muscle immunolabelled for Kit, Cx43 and the merged image of G and H, respectively. Cx43 staining is present in both ICC_my and in the circular smooth muscle. Note that there is a region that is obviously devoid of Cx43 immunostaining in the circular muscle immediately adjacent to the ICC_my (*). Scale bar = 50 μm (A–C) or 10 μm (D–I).