[Study on the peritoneal stomata and absorptive mechanism of ascites]

The peritoneal stomata in sixteen human specimens were studied by SEM, TEM and ODO freeze fracture techniques. In order to prove that the peritoneal stomata are the passage ways by which ascites is absorbed from the peritoneal cavity, animal experiments were performed. The results showed that the peritoneal stomata, which were only found between the cuboidal cells, were formed by the cytoplasmic processes of nearby cells. There were no basement membranes in the peritoneal stomata or the cuboidal cells which formed the peritoneal stomata. Microfilaments were observed in the cuboidal cells. Cytoplasmic processes of mesothelial cells and networks of connective tissue were found in the peritoneal channels. These had networks which formed the floor of each stomata and the roof of each lacunae. We observed that numbers and diameters of the peritoneal stomata were increased in mice with ascites. Red cells and carbonic particles injected into the peritoneal cavity were absorbed by the peritoneal stomata. So the microfilaments of the cuboidal cells, the cytoplasmic processes, and the fiber networks in the peritoneal channels can adjust the absorptive properties of the peritoneal stomata. The peritoneal stomata are an important pathway for draining ascites from the peritoneal cavity.