Evidence for a humoral regulation of erythropoiesis; studies on a patient with polycythemia secondary to regional hypoxia.

Hypoxia By FREDERICK ST0IILMAx, JR., CnmAltLEs E. RATH AND JOHN C. ROSE T HE REGULAR OCCURRENCE of polycythemia in chronsic hypoxic states’ . 2 ansd the suppressions of erythropoiesis by inscreases ins barometric pressure3 or the oxygens conscenstrations of insspired air46 indicate that the state of blood oxygersation is a major factor ins regulatilsg the rate of erythrocytogemsesis. Ins the past, most iisvestigators have conssidered blood or tissue oxygens tensions as the critical factor.7 . Recenst evidensce, how-ever, suggests that the oxygens constenst is equally as importanst as the PO2 in the regulation of erythropoiesis. For example, Granst and Root9 founsd a reductions of 02 coistenst ins arterial l)lood and the boise marrow of subjects with acute or chroisic ansemia. Also, in t.raissfusiots polycythemia there is ans increased O consteist ansd suppressions of erythropoiesis evens though the PO2 of peripheral blood, and presumably tissue, is unschanged.1#{176} The mechansisms by which alterations ins PO2 or 02 constenst constrol the rate of red cell productions are the subject of speculation. It has beets suggested that either the partial pressure of oxygens (pO2) ins the bonse marrow regulates the rate of erythropoiesist ‘ or a decrease irs arterial oxygeis teission results ins the formations of ais unidenstified humoral (plasma) factor, ‘ ‘hemopoietinse, ‘ ‘ capable of stimulatinsg eryt.hropoiesis.’2 ‘ 13 Some clinical alsd experimelstal observationss might suggest that the latter is elaborated by the pituitary 1418 or thyroid 20