花背蟾蜍消化道5-羟色胺细胞的分布及形态学特征

采用卵白素-生物素-过氧化物酶复合物（avidin-biotin-peroxidase complex technique，ABC）免疫组织化学方法对花背蟾蜍（Bufo raddei）消化道5-羟色胺（5-HT）细胞的分布密度及形态学特征进行了观察。结果显示，5-HT细胞在花背蟾蜍整个消化道中均有分布，食管、贲门、胃体和幽门的分布密度都显著高于肠道各段，胃幽门部密度最高，胃体部其次，直肠部最低。消化道各个部位5-HT开放型和闭合型细胞的比值变化范围为2.48~4.71。消化道各段均以开放型细胞为主，大多呈锥体形、梭形或不规则形，少数为闭合型细胞，呈圆形或椭圆形。花背蟾蜍5-HT细胞的形态学特征与其他两栖动物相似，但分布密度有自身特征，可能与其食性和善于摄取活动性小的食物的生活习性有关。

Distribution and Morphological Characteristics of 5-Hydroxytryptamine Cells in the Digestive Tract of Bufo raddei

Distribution and morphological characteristics of 5-hydroxytryptamine (5-HT) cells in the digestive tract of Bufo raddei were observed by avidin-biotin-peroxidase complex immunohistochemical method. The results were as follows: 5-HT cells distributed throughout the whole digestive tract with the highest density in the stomach pylorus, the second highest in the fundus, and the lowest in the rectum. The distributive density of 5-HT cells in esophagus, cardia, fundus, and pylorus was significantly higher than that of any other region of small intestine and rectum. The ratio range between open and closed populations of 5-HT cells recorded along the digestive tract was 2.48-4.71. Most cells along the digestive tract belonged to the open population, which were pyramid-like, shuttle-like, or irregular in shape. The closed population was occasionally observed, round or oval in shape. Morphological characteristics of 5-HT cells in the digestive tract of B.raddei are similar to those of other amphibians, but the distributive pattern of these cells has its own characteristics, and this may be related to the diet and life habitat of this species, which is good at feeding on small animals with weak activities.