Enhancement of the recovery of hemopoietic system with carbon particles in irradiated mice

Effect of carbon treatment on retention of peripheral erythroches and on hemopoietic recovery following irradiation was studied. Life-span of /sup 51/Cr- labeled erythrocytes was shortened to about three-fourths that of normal mice by irradiation (500 R). By previously blockading RES with carbon particles, this accelerated destruction of erythrocytes was prevented. Proliferation of lymphoreticular tissues after irradiation was significantly enhanced by administration of 10 mg of carbon particles. Similar enhancement of erythropoietic recovery was also observed in the carbon-treated mice. Studies on the survival of endogenous spleen colony forming cells revealed that several times as many cells were protected by carbon treatment before or after irradiation. As a possible mechanism for the radioprotective effect of carbon particles, the following is proposed: elongation of the survival time of slightly injured RBC due to the functional blockade of RES and the prevention of internal hemorrhage by carbon-induced reinforcement of sinuses and sinusoide, higher survival of hemopoietic stem cells and enhancement of hemopoietic recovery which follows the above-mentioned response. (auth)