Thrombopoietin: Basic Biology and Clinical Effects
I. PHYSIOLOGY OF MEGAKARYOCYTE DEVELOPMENT The generation of platelets from their marrow progenitors is an enormously important and complex process. Each day the adult human produces 2 1011 platelets, a number which can increase 10-fold in times of heightened demand. Megakaryocyte (MK) and platelet formation is dependent on the productive interaction of hematopoietic stem and progenitor cells, marrow stromal elements, and multiple endocrine and paracrine hormones. Our evolving understanding of the humoral regulation of megakaryocyte development and how we might manipulate this process for therapeutic benefit will form the focus of this chapter.