[Qualitative and quantitative analyses on the development of NKA-immunoreactivity in the esophagus of rats].

Objective: To explore the expression and change of neurokinin A (NKA) in rat esophagus during development.
Methods: PAP immunocytochemistry method and image analysis were used to detect systematically the expression of NKA in rat esophagus from the 13th day of embryo to adult stage.
Results: In rat esophagus, the positive varicosities and fibres could be observed in the circular muscle layer and the muscularis mucosae layer at the 21st day before birth. With the development of rat digestive tract, the neurokinin A-immunoreactivity (NKA-IR) positive nerves could be observed gradually in the epithelium, submucosa, longitudinal muscle layer, myenteric plexus and submucosal plexus, while mature nerve fibres could be seen at one month after birth. The results of quantitative analysis are in accord with the developmental change of NKA-IR in esophagus.
Conclusion: The ontogeny and development of NKA in rat esophagus proceeds from the last day before birth to 4 weeks after birth. NKA may play an important role in the development of rat esophagus.