Influence of Cobalt, Sheep Erythropoietin and Several Hormones on Erythropoiesis in Bone Marrows of Isolated Perfused Hind Limbs of Dogs

A technic has been developed for studying the femoral bone marrow of the dog by perfusing the isolated hind limb. With the use of this method, bone marrows were perfused for 4-6 hours with donor dog blood alone and blood containing sheep erythropoietin, cobalt, growth hormone, hydrocortisone, 3,5,3'-triiodothyronine or testosterone. Significant increases were seen in nucleated erythroid cell counts within femoral marrows perfused with blood containing sheep erythropoietin and cobalt. A slight increase was also noted in the bone marrows from limbs in which growth hormone was added to the perfusion system. It may be concluded from these experiments that erythropoietin, cobalt and growth hormone are capable of stimulating erythroid hyperplasia in the bone marrow directly.