IMMUNOHISTOCHEMICAL STUDY ON ENDOCRINE CELLS IN THE GASTRO -ENTERO -PANCREATIC SYSTEM OF CHINEMYS REEVESII

Identification, localization, distribution and morphology of edocrine cells in the gastro-entero-pancreatic system of Chinese three keeled pond turtleChinemys reevesii were studied in streptavidin peroxidase(S-P) immunohistochemical method with six gut hormone antisera. Four types of edocrine cells were founded in the pancreas of C. reevesii, namely:5-Hydroxytryptamine(5-HT), somatostatin (SS), glucagon (Glu), polypeptidem (PP) edocrine cells.SS and Glu cells mainly distributed collectively in the pancreas islet with large quantity.On the other hand 5-HT and PP cells scatterly located in the pancreas alveoliwith small quantity. Gastrin(Gas) and Substance P(SP) cellswere not detected in the pancreas of C. reevesii,Five types of edocrine cells were obsesued in the digestive tract of C. reevesii, they were 5-HT, SS, Gas, Glu and SP cells. 5-HT cells distributed throughout the digestive tract,with the highest density in the duodenum,the second highest in the jejunum, and the lowest in the Ileum and rectum.SS cells mainly located in the each region of stomach, and occasionally occurred in the esophagus. Gas cells were mainly detected in the stomachus pyloricus and also have a few in the duodenum. Glu cells were presented from stomachus corpus to jejunum with the highest density in the stomachus pyloricus.Substance P cellswere only found in the stomachus pyloricus. Cells showing immunoreactivity to PP were not detected in the digestive tract of C.reevesii. Comparing with other reptiles, some common features in distribution of endocrine cells in the gastro-entero-pancreatic system of C. reevsii were found,which exist in digestive physiology, but the difference among them was also significant.