Migration of hematopoietic stem cells in dogs

Abstract

The rate of migration of bone marrow hematopoietic stem cells (HSC) was studied by two methods in experiments on 54 dogs. In the first case the dogs were irradiated subtotally with an absolutely lethal dose of 550 R, with both knee joints screened. When the screened areas were inactivated by irradiation in a dose of 2000 R 7 days after the first irradiation, the survival rate of the animals was 12.5%, but in the case of inactivation after 14 days, all the dogs survived. In the second case both knee joints were irradiated initially in a dose of 2000 R. After subsequent subtotal irradiation in a dose of 550 R, with the previously irradiated regions screened, all the animals died if the second irradiation was given after 7 days, whereas 20% of the animals survived if the time between irradiations was increased to 31 days. It is concluded that migration of HSC in dogs is much lower in degree than in mice.