Adrenergic modulation of erythropoiesis: in vitro studies of colony-forming cells in normal and polycythaemic man.

The effect of hormonal interactions on human erythroid colony growth has been studied using the beta adrenergic agonist, isoproterenol. The growth of colonies derived from both erythroid burst-forming cells (BFU-E) and erythroid colony-forming cells (CFU-E) was enhanced in the presence of isoproterenol. While isoproterenol was effective at all concentrations of erythropoietin (Ep) in cultures of marrow cells, an increase in BFU-E-derived colonies in peripheral blood cultures could be detected only at suboptimal levels of Ep concentrations. The isoproterenol effect was blocked by an agent with beta 2 receptor specificity (butoxamine), and L-isomeric configuration (L-propranolol). The stimulatory effect appeared to be mediated by a receptor different from that for Ep or for phytohaemagglutinin-stimulated leucocyte conditioned medium. Circulating BFU-E from eight patients with polycythaemia vera were also studied. Those colonies which grew in the absence of added Ep increased with isoproterenol; in cultures from normal subjects and in patients with secondary erythrocytosis, agonist stimulation was seen only in the presence of Ep. These studies provide evidence that the growth of both normal and neoplastic erythroid progenitors may be modulated by hormonal interactions.