Prevention of gamma radiation induced anaemia in mice by diltiazem.

Intraperitoneal administration of diltiazem (DTZ), half an hour prior to whole body gamma irradiation (2.5, 5.0, & 7.5 Gy), showed the protection of animals from radiation-induced anaemia. Radiation exposure significantly (p < 0.001) reduced the number of pro- and normoblasts in bone marrow and RBC counts, hemoglobin (Hb), hematocrit (Hct ), and erythropoietin (EPO) level in blood, but increased myeloid / erythroid ratio. At all the radiation doses, the maximum decrease in these values was noted on the 3rd day, followed by a gradual recovery from the 7th day, but it was not recorded as normal even until the end of experimentation. In animals pretreated with DTZ, these values were measured higher at all the time periods in comparison to corresponding control, and these were almost normal at the last autopsy interval only at 2.5 Gy radiation dose. DTZ maintained the higher erythropoietin level in blood, which acted on bone marrow and spleen colony forming unit for erythroblast (CFU-E), and stimulated such cells to produce RBCs. These results confirm that DTZ has the potency to alter anaemic condition favorably through the protection of bone marrow stem cells, and subsequently it maintains the higher number of pro- and normoblasts in bone marrow, RBC counts, hemoglobin (Hb), hematocrit (Hct) percentage, and erythropoietin level in blood and the lower myeloid/erythroid ratio in bone marrow.