The stomach of Rhinella icterica was analyzed at light microscopy, employing histochemical techniques, lectin histochemistry, and immunohistochemistry for identifying enteroendocrine cells (EC). Although the stomach was composed of fundic and pyloric regions, its wall is formed by mucosa, submucosa, muscularis, and serosa. The mucosa was lined by a simple columnar mucous epithelium, supported by loose connective tissue. Several tubular, simple glands were composed of mucous neck cells, containing oxynticopeptic cells and EC cells. The mucous neck cells were rich in neutral glycoconjugates. The oxynticopeptic cells were predominant in fundic glands, exhibiting weaker alcianophilic reaction at their apical cytoplasm. Serotonin (5-HT) immunoreactive (IR) cells occurred throughout the entire stomach, preferentially located among mucous cells at upper part of the fundic glands. The muscularis mucosae, formed of smooth muscle, separated the mucosal layer from the submucosa, both of which were constituted by loose connective tissue, but without glands. Lymphoid modules occurred in the mucosa at the boundary at the stomach and the gut. In addition, the muscularis was constituted by two sublayers, the circular internal and the longitudinal external, being recovered by the connective tissue of the serosa.

Pelli-Martins, A.A., Machado-Santos, C., Sales, A. and de Brito-Gitirana, L. 2012. Histochemical, immunohistochemical, and ultrastructural observations of the esophagus morphology of Rinella icterica (Anuran, Bufonidae). -Acta Zoologica (Stockholm) 93: 373-380.The esophagus of Rinella icterica was analyzed by employing histochemical methods and lectin histochemistry at light microscopy as well as by transmission electron microscopy. The mucosa was composed of a ciliated columnar pseudostratified epithelium with goblet cells, overlying a lamina propria. The goblet cells contained neutral and acid glycoconjugates and were positive for galactose residues. Moreover, two types of goblet cells were identified; one type was positive for mannose, and the other was negative. Serotonin-immunoreactive cells (5HT-IR) occurred randomly scattered at the base of the epithelium; they were also localized between the mucous cells of the gland. Both submucosa and adventitia were composed of loose connective tissue, and the muscularis was formed by smooth muscle. Although the basic morphology of the esophagus of R. icterica is similar to that of mammals, the esophagus showed some morphological differences that are likely to be related to the specific physiology of the tissue.