In vitro stimulation of primate hemoglobin synthesis by L-thyroxine

Bone marrow cells from adult and abortus primates (marmosets) were incubated in vitro to determine their responsiveness to L-thyroxine. 3H- leucine incorporation into purified globin chains was the parameter assayed to determine responsiveness. Bone marrow from spontaneously aborted animals consistently was stimulated by the presence of physiologic levels of L-thyroxine. Bone marrow cells from adult animals were unaffected by the hormone.