Mesenteric hemopoietic colonies: occurrence in BALB/c mice after transplantation of syngeneic normal or leukemic hemopoietic cells.

Intraperitoneal (ip) inoculation of BALB/c mice with syngeneic hemopoietic cells results in the formation of 'Mesenteric Hemopoietic Colonies' (MHC). In lethally irradiated mice actively growing erythroid, myeloid and megakaryocytic, or mixed colonies form and soon become confluent. It is therefore concluded that in mice the mesentery is a suitable site for growth of hemopoietic cells. The mesentery might play an important role in the recovery of the hemopoietic system in lethally irradiated mice, being the primary site of proliferation of stem cells and/or CFU before their migration to bone marrow and spleen. Bone marrow and spleen cells from animals infected with Rauscher Leukemia Virus (R-MuLV) also produce MHC and spleen colonies after ip injection into lethally irradiated mice. In addition to the undifferentiated cells in the MHC, cells with limited differentiation and/or retarded maturation were identified. The cytologic pattern of the majority of cells in MHC was of mixed type.