Spleen colony formation and hemopoietic restoration in lethally x-irradiated mice after injection of isogenic peritoneal cells.

Abstract : THE CAPACITY OF INTRAVENOUSLY INJECTED CELLS FROM PERITONEAL FLUID, PERIPHERAL BLOOD, LYMPH NODES, THYMUS AND BONE MARROW OF MICE TO RESTORE HEMATOPOIESIS IN LETHALLY X-irradiated (880 rad) isogenic recipients, was investigated. Thirtyday survival, and visible colony formation in the spleen were employed as he criteria. Administration of 6 million or 11 million peritoneal cells, and 6,400,000 or 15 million peripheral leukocytes afforded protection against mortality, and elicited colonies in the spleen; comparable effects were observe after injection of 110,000 marrow cells. The injection of 34 million adult lymph node cells or of 9 million thymus cells from newborn mice had no effect on mortality, nor did they elicit spleen colony formation. A corelation appears to exist between the capacity of isogenic cells to restore hemopoiesis in lethally irradiated mice and their ability to elicit visible colony formation in the spleen. The evidence suggests that normal peritoneal cell populations and peripheral blood leukocytes contain hemopoietic stem-cell elements, with a frequency 30 to 50 times lower than among bone marrow cells. No evidence was adduced to support the concept that normal lymphoid tissue lymphocytes give rise to hemopoietic cell lines. (Author)