Three-dimensional structure of mucosal and submucosal lymphatics in rat small intestine.

The organization of the lymphatic system in the rat ileum was investigated by the three-dimensional reconstruction using serial sections after dilatation of lymphatics. This method has an advantage to exclude possible artifacts in the conventional corrosion cast method. The villus possessed several lacteals and connected to each other by sinus. Two or three perpendicularly oriented lymphatics descended and led into the submucosal lymphatic network. In mucosa and submucosa, no valvular structure was detected. This study confirmed the voluminous lacteals and fine network structure of lymphatics in submucosa without valves, suggesting great potential to keep lymph and to drain soluble factors and cellular components.