The clonogenic response of bovine aortic endothelial cells in culture to radiation.

The effect of ionizing radiation on the survival of bovine aortic endothelial (BAE) cells was determined by the in vitro colony formation method. The BAE cells were cultured in Dulbecco's modified Eagle's medium (DMEM) supplemented with 10% calf serum, antibiotics, and growth factors obtained from the culture of mouse S-180 cells. The cultured BAE cells were positive to the staining of antibodies against human factor VIII and formed clones in plastic culture flasks with a plating efficiency of about 11%. The survival curve of the BAE cells following an exposure to a single dose of X rays was characterized by D0 = 101 rad, Dq = 65 rad, and an extrapolation number (n) of 1.9. These parameters were not modified by the absence of growth factors at the time of irradiation. The response of BAE cells to radiation was dose-rate dependent. The split-dose studies demonstrated that the BAE cells were able to repair sublethal radiation damage within 1 h after irradiation.