Ultrastructure and Morphometric Analysis of Interstitial Cells of Cajal in the Gastric Wall of the Bullfrog (Rana catesbeiana)

Interstitial cells of Cajal (ICC) play a vital role in the gastrointestinal motility. However, information on ICC in lower vertebrates is rare. Here, ICC and ICC-like features of the gastric wall in the bullfrog (Rana catesbeiana) were observed by light microscopy and transmission electron microscopy. The lengths and distances of the ICC/ICC-like features were measured by morphometric analysis. The gastric wall contained mucosa, submucosa, tunica muscularis, and serosa. The gastric glands contained mucous cells and oxynticopeptic cells. The ICC with 1–3 processes were located among smooth muscle cells (SMC) of the tunica muscularis. Moreover, the ICC-like features were observed among oxynticopeptic cells of the mucosa. The processes of ICC established direct contacts with SMC. Also, the gap junctions were observed between the processes of ICC and nerve fiber bundles in the tunica muscularis. The multivesicular bodies, including shedding exosomes, were frequently observed between ICC and SMC. In addition, ICC-like features and their processes were observed in close proximity to oxynticopeptic cells and blood vessels. Our findings illustrated that ICC are present in the gastric tunica muscularis, and ICC-like features were in the mucosal lamina propria of the gastric wall of R. catesbeiana. These histological evidences supported the notion that ICC are implicated in gastric motility.

Review of Management of Gastrointestinal Stromal Tumor in Low-Resource Centers

Gastrointestinal stromal tumors (GIST) account for 1% to 3% of gastrointestinal tract tumors and are the most common of the mesenchymal tumors. Carcinogenesis of GIST arises in the interstitial cells of Cajal (ICC) and in the myenteric plexus of the gastrointestinal tract due to a mutation of the kinase receptor (KIT, also known as CD117) and the platelet-derived growth factor A (PDGFA) gene leading to activation of the tyrosine kinase receptor. The exact incidence and prevalence of GIST is not known. Symptoms of GIST are non-specific; they present with GI bleeding due to ulceration (50%), abdominal pain (20% to 50%), dysphagia (esophageal GIST) and GI obstruction (10% to 30%) (7,10). Signs include abdominal mass and fullness. A computerized tomographic (CT) scan is the preferred imaging to evaluate GIST. Diagnosis is confirmed by immunohistochemical (IHC) staining a of biopsy sample for medical treatment tyrosine kinase inhibitors (TKI). Surgical resection with negative microscopic margins is the gold standard treatment of GIST. TKI are required for tumor reduction to increase chances of respectability (neoadjuvant therapy) or to prevent recurrence and reduce the progression of advanced, resectable GIST.