AN IMMUNOCYTOCHEMICAL AND ULTRASTRUCTURAL-STUDY OF THE LARVAL ANTERIOR INTESTINE OF THE FROG RANA-TEMPORARIA, WITH ESPECIAL REFERENCE TO ENDOCRINE-CELLS

Endocrine cells of the larval intestine of Rana temporaria tadpoles ha ve been identified by argyrophilic, immunocytochemical and electron-mi croscopical techniques. Scarce endocrine cells have been found in both the short non-absorptive zone immediately following the stomach, and in the rest of the anterior intestine, Endocrine cells are frequently seen to extend a cytoplasmic process towards the lumen. Immunoreactivi ty for serotonin, somatostatin, bombesin and cholecystokinin-8 has bee n detected. According to the ultrastructural traits of the endocrine g ranules, three larval intestinal endocrine populations have been diffe rentiated.