ABSTRACT
Hematopoiesis depends on a highly complex series of events in which a small population of stem cells needs to generate large populations of maturing cells. In analogy with the immune system, other neurotransmitters or other neuroendocrine circuits might also affect hematopoiesis. The evidence of a neuroendocrine influence on endogenous granulocyte macrophage colony stimulating factor production has important basic and practical implications. In most forms of cancer, a major barrier to achieving the best possible response to cancer chemotherapy is the hematological toxicity of available agents, which limits optimal dosing. The multiplicity of hematopoietic regulators seems to reflect the need for a subtle physiological control of the complex cell mixtures required in certain situations. Single hematopoietic regulators are already used to counteract the bone marrow toxicity of cancer chemotherapy compounds or to enhance regeneration after bone marrow transplantation.
