Abstract:

Abstract：To observe the distributive density and morphology of 5-Hydroxytryptamine immunoreactive cells (5-HT cells) in the digestive tract of Coccothraustes coccothraustes by using the ABC（avidin-biotin-peroxidase complex）immunohistochemical technique.The results indicated that the 5-HT positive immunoreactive cells could be observed throughout the digestive tract, except oesophagus and crop. The highest density is in duodenum，but the lowest cell density is found in the stomach and rectum. The 5-HT cells have different shapes including round, shuttle-like, tapering，ellipse and so on. The cells widely distributed in basal epithelial cells，between epithelial cells and glandular epithelial cells. According to the morphology of the endocrine cells,We suggest that 5-HT positive immunoreactive cells should have both endocrine and exocrine functions, and the Cell distributive formation is related to the function of each part of digestive tract of Coccothraustes coccothraustes .