Some Heterocyclic Nitrogenous Compounds as Radioprotectants for Hematological Levels in X-Irradiated Mice

In normal controls, the levels of hemoglobin concentration and hematocrit values remained almost unchanged throughout the experimentation period. Intraperitoneal administration of imidazole and benzimidazole affected rapid pharmacodynamic incidences which were not detected with cysteamine. Administration of imidazole did not induce detectable change in the level of hemoglobin concentration but slightly decreased the hematocrit value. Benzimidazole created slight depression in hemoglobin concentration and exerted no effect on hematocrit value. Cysteamine caused slight depression of both hemoglobin concentration and hematocrit value. Those changes were readily restorable with imidazole and benzimidazole while those with cysteamine lasted for more than three days. Irradiation caused progressive decrease in hemoglobin concentration and hematocrit values which continued till the death of the animals. A significant increase in the sedimentation rate of red blood cells was recorded. Irradiation of chemically protected animals caused initial decrease in hemoglobin concentration and hematocrit values which lasted till the fifths post-exposure day. Later, gradual restoration of normal levels of hematological values was recorded. Restoration was more rapid with benzimidazole than with imidazole, while cysteamine lied half way in its action. The increase in sedimentation rate of red blood cells was less pronounced and gradual restoration of the normal sedimentation rate was maintained during the post-irradiation time. It seems likely that the radioprotectants act on cellular and subcellular levels in the protected tissues but the actual role played by such compounds still awaits further investigation. Imidazole and benzimidazole proved to be effective radioprotectants of the hematopoietic tissue. Benzimidazole proved to exert the best radioprotective characters amongst the tested compounds in this concern.