ACUTE OBSTRUCTIVE PARASTERNAL LYMPHEDEMA PRODUCED IN RATS WITHOUT SURGERY

Abstract

Although rat red blood cells (RBC) were altered by pretreatment with glutaraldehyde, they nonetheless were well absorbed into mediastinal lymphatics of Lewis rats after intraperitoneal injection. Unlike normal RBC, they did not pass freely through the draining mediastinal lymph nodes. Instead, clumps of free and phagocytosed glutaraldehyde-treated RBC distended and obstructed the afferent lymphatics and the sinuses of draining lymph nodes. The lymphatic obstruction caused edema in a clearly defined compartment of fatty connective tissue between the muscle layers of the ventral chest wall. The obstructive lymphedema interfered with the immunizing effect of small doses of sheep RBC injected intraperitoneally. This study emphasizes the potential utility of the rat's mediastinal lymphatics for studies of lymphatic leakage and obstruction.