title: In vitro studies on the sensitivity of canine granulopoietic progenitor cells (GM-CFC) to ionizing radiation: differences between steady state GM-CFC from blood and bone marrow.
abstract: The radiosensitivity of the granulopoietic progenitor cells (GM-CFC) from blood and bone marrow of dogs under steady state conditions was studied by in vitro irradiation with 280kV X-rays (approximately 0.56 Gy/min). The dose-effect relationship for colony formation was determined for the dose range from 0 to 3 Gy by means of three different models. A simple exponential function revealed an optimal approximation to the experimental data obtained for the clonogenic cells from the two different sources. The D0 values are 0.261 +/- 0.009 Gy and 0.600 +/- 0.011 Gy for the GM-CFC from blood and bone marrow, respectively. Irradiation of blood-derived GM-CFC in the presence of pre-irradiated bone marrow cells or irradiation of bone marrow cells as a mixture with pre-irradiated blood cells led to small changes only in the survival curves. According to the dose-effect relationship obtained from these studies the GM-CFC of the dog seem to be the most radiosensitive clonogenic haemopoietic cells among the different mammals.
mesh_terms: D000818:Animals; D002470:Cell Survival / Q000528:radiation effects; D004285:Dogs; D004307:Dose-Response Relationship, Radiation; D006098:Granulocytes / Q000528:radiation effects*; D006412:Hematopoietic Stem Cells / Q000528:radiation effects*