Immunohistochemical techniques incorporating the streptavidin peroxidase method were used to study the morphological structure and the distribution density of 5-hydroxytryptamine(5-HT),Somatostatin(SS),Gastrin(Gas),Glucagon(Glu),Pancreatic Polypeptide(PP) and Substance P(SP) in the digestive tract of the Arctic fox(Alopex lagopus).The results indicated that the shape of endocrine cells in the digestive tract were of many forms: round,ellipse or spindle shape.The endocrine cells were mainly located between the epithelia of the gastric gland,intestine and intestinal gland.The distributive density of 5-HT immunoreactive cells were the maximum in the colon,medium in the rectum and jejunum,and the least in the fundus,duodenum,ileum,and pylorus.They were not found in the esophagus,cardia or cecum.SS positive cells were located in the pylorus mostly,but were not detected in the esophagus,cardia and cecum.Gas positive cells were the most in the duodenum,while they were not found in the esophagus,cardia,colon,rectum and cecum.Glu positive cells were distributed in the pylorus,fundus and jejunum,but were not found in other parts of digestive tract.PP positive cells were the most in the jejunum,the second-most in frequency in the colon and rectum,while they were not found in the other parts.SP positive cells were mainly distributed in the pylorus,while fewer were found in the colon,and they were not found in other parts.The location of 5-HT positive cells were mostly distributed in the colon.SS,Gas,Glu and SP positive cells were mostly distributed in the pylorus,and PP positive cells were mostly distributed in the jejunum.
