ABSTRACT
Objective To explore the expression and change on the neurokinin A(NKA) of rat ileum during the development. Methods PAP immunohistochemistry method and image analysis were used to detect systematically the expression of NKA in rat ileum from E13 to adult stage. Results 1.In rat ileum, the NKA-IR could first be found in the myenteric plexus at E17, and then appeared on the longitudinal muscle layer, circular muscle layer, intestinal villus, intestinal gland, submucosa and deep muscular plexus. On P30, they showed the distribution feature of adult rat.2.The results of quantitative analysis were in correspondence with the developmental change of NKA-IR in ileum.3.The NKA-IR positive cells showed the typical feature of morphology and distribution of gastrointestinal endocrine cells.Conclusion 1. The ontogeny and development of NKA in rat ileum mainly appeare in the last E1 week and P4 weeks, whereas the density of positive fiber in villus is not as same as adulthood until P60. 2.There are two key periods during the development of NKA in rat ileum. The first crucial stage is from the last El week to P1 week. The second important stage is in the end of P4 weeks. 3.The NKA-IR cells may be the endocrine cell which produces NKA in rat digestive tract.4.NKA may play an important role in the development and physiological function of rat ileum.