[Effect of acute anemia or polycythemia on blood flow and iron transport in bone marrow].

Iron has been shown to be the limiting factor for erythropoiesis. The anemia and polycythemia effect on iron supplied to the bone marrow has been studied in a group of rabbits, by modifying the hematocrit without altering of the blood volume. The cardiac output and the percentage of blood flow to the skeleton was measured using 57Co and 113Sn radiolabelled microspheres, before and after the exchange of blood by plasma or red blood cells concentrates. In addition, ferrokinetic measurements were performed with 55Fe and 59Fe. The production of an acute anemia induced an increase in the cardiac output from 156 +/- 35 to 239 +/- 89 ml/min/kg and a decrease in the percentage of the total blood flow to the skeleton from 7.58 +/- 2.51 to 4.63 +/- 1.8. The production of an acute polycythemia induced a decrease in the cardiac output (97 +/- 28 ml/min/kg) and an increase in the percentage of the total blood flow to the bone marrow (11.69 +/- 4.03). However, in both cases, the absolute amount of blood flow and iron flow to the bone marrow were similar to the controls. These studies demonstrate that anemia or polycythemia per se do not determine the iron supply to the bone marrow.