Passage of radioactive erythrocytes from the peritoneal cavity into the blood stream during experimental ascites.

Intraperitoneal injection of red cells tagged with radioiron into dogs with experimental ascites demonstrated that such cells were rapidly transferred into the circulating blood. When the experimental animals were not actively producing ascitic fluid, 43.4, 67.0, and 56.4 per cent respectively, of the administered radioactive red cells passed to the blood in 72 hours. In the same three dogs during active ascitic fluid formation, 25.9, 51.2, and 38.8 per cent of the administered radioactivity was removed in a similar period. The amount of radioactivity in the blood stream, consequent on the passage of red cells from the peritoneal cavity into the circulation, becomes nearly constant in 48 hours, whereas for radioactive plasma proteins the plateau is attained in 24 hours (Fig. 1). In normal dogs (16), the passage of red cells from the peritoneal cavity was complete in 72 hours, while in ascitic dogs, 5 to 47 per cent of the injected tagged red cells remained behind in the peritoneum after the same period.