Red cell production in the continuously irradiated mouse.

Abstract

Abstract A study has been made of changes in red cell production in the mouse undergoing continuous irradiation at 40 rads/day. There is an early rapid fall in haemoglobin level followed by a continuing gradual fall. The initial decrease in the incorporation of 59Fe into circulating red blood cells is shown to be due to a low reticulocyte count and not to any reduction in red cell production. The repopulating ability of femoral bone marrow falls drastically and reaches 5 per cent of normal after three weeks of irradiation, by eight weeks, the rate of red cell production has risen to above normal levels, due to a large increase in splenic erythropoiesis which is additional to the normal level of erythropoiesis in the bone marrow. Continuous irradiation increases considerably the random rate of destruction of mature red blood cells. These results are compared with the response of rats to continuous irradiation at various doserates.