摘要AIM: To observe the regional distributions and morphological features of nesfatin-1/nucleobindin-2 (NUCB2) immunoreactive (IR) cells in the rodent digestive system. METHODS: Paraffin-embedded sections of seven organs (pancreas, stomach, duodenum, esophagus, liver, small intestine and colon) dissected from sprague-dawley (SD) rats and institute of Cancer Research (ICR) mice were prepared. The regional distributions of nesfatin-1/NUCB2 IR cells were observed by immunohistochemical staining. The morphological features of the nesfatin-1/NUCB2 IR cells were evaluated by hematoxylin and eosin (HE) staining. Fresh tissues of the seven organs were prepared for Western blotting to analyze the relative protein levels of NUCB2 in each organ. RESULTS: Immunohistochemical staining showed that the nesfatin-1/NUCB2 IR cells were localized in the central part of the pancreatic islets, the lower third and middle portion of the gastric mucosal gland, and the submucous layer of the duodenum in SD rats and ICR mice. HE staining revealed that the morphological features of nesfatin-1/NUCB2 IR cells were mainly islet cells in the pancreas, endocrine cells in the stomach, and Brunner's glands in the duodenum. Western blotting revealed that NUCB2 protein expression was higher in the pancreas, stomach and duodenum than in the esophagus, liver, small intestine and colon ( P = 0.000). CONCLUSION: Nesfatin-1/NUCB2 IR cells are expressed in the pancreas, stomach and duodenum in rodents. These cells may play an important role in the physiological regulation of carbohydrate metabolism, gastrointestinal function and nutrient absorption.