目的　研究内脏高敏感大鼠肠道及脊髓内的 5 羟色胺 (5 HT)能神经元及神经纤维的分布 ,肥大细胞脱颗粒对 5 HT能神经元及神经纤维的影响。方法　内脏高敏感大鼠分为两组 (A组和B组 ) ,B组为事先给予促肥大细胞脱颗粒释放剂com pound 4 8 80的内脏高敏感大鼠。对内脏高敏感大 Objective To investigate the distribution of serotonergic (5 HT) neurons and nerve fibers in gut and spinal cord of visceral hypersensitive rats and the effect of mast cell degranulation on 5 HT neurons and nerve fibers. Methods The visceral hypersensitivity rats were divided into two groups (group A and group B). Group B was visceral hypersensitive rats given prior administration of a mast cell degranulation-releasing agent, com pound 4 8 80. Highly sensitive to the internal organs