Though the knowledge about hemodynamics of the liver was being advanced recently by means of new techniques, the role of lymphatics on ascites formation is not yet clarified because of its variabillity. Several relationships of lymphatics to ascites formation in experimental portal hypertension were analyzed in this paper.
The results obtained were summarized as follows:
Section 1; Prehepatic portal hypertension
a) The gross production of ascites in dogs by means of simple constriction of the portal vein was hardly possible, because only small amount of the fluid spilled over from the mesenterial vessels in the wall of well-developed intestinal lymphatics.
b) However, considerable amount of ascites developed by both constriction of the portal vein and ligation of the thoracic duct in the neck. In these dogs by modified Gibson's technique using RISHA and small pieces of filter paper an increase of the fluid in volume from the Intestinal surface was not found, but signficant increase of the production from the liver capsule was noted.
Section 2; Posthepatic portal hypertension
a) Ascites was grossly accumulated by constricting hepatic veins or inferior vena cava above the liver. In these dogs, ascites occurred not only due to an increased fluid production from the liver capsule, but also decreased absorption of the fluid by the peritoneum.
b) The pattern of the radioactivity in thoracic duct lymph, portal vein blood, and femoral vein blood was studied serially in these dogs with ascites after injecting RISHA and Na
24Cl into ascites. Most of the RISHA injected was absorbed into diaphragmatic lymphatics and appeared immediately in the thoracic duct lymph. This was interesting enough to state that small amount of the radioactivity of released I
131 from the albumin was discovered in the portal blood. On the contrary, most of the Na
24Cl injected was directly absorved into the portal blood.
c) Slight decrease of ascites was observed when massive thoracic duct lymph was drained out freely. It was ascertained that this fact happened due to significant loss of circulating plasma volume.
d) The role of congestion of thoracic duct lymph on ascites formation was studied by connecting thoracic duct directly to right atrium a polyethylen tubing. Despite the pressure in the thoracic duct dropped significantly after the procedure, no significant decrease of ascites was observed.
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