Effects of radiation on capillary endothelial cells derived from Mongolian gerbil brain

Confluent monolayers of capillary endothelial cells derived from Mongolian gerbil brain were irradiated with a single exposure of x-rays, and their radiosensitivity and sequential changes in morphology and capacity to produce prostacyclin were examined. The radiobiological parameters that characterized the dose-response survival curve of these cells were found to be n = 1.9, Dq = 120 rad, and Do = 190 rad. Morphologically, nuclear and cytoplasmic swelling, vacuolation of cytoplasm, and giant cell formation occurred in a dose-dependent manner beginning as early as 24 hours after irradiation. The capacity to produce prostacyclin was significantly enhanced at 24 hours, but less significant at 72 hours after irradiation. The present study suggests that the radiosensitivity of brain capillary endothelial cells is lower than that of endothelial cells originating from larger vessels, and that their changes in morphology and capacity to produce prostacyclin are similar to those of endothelial cells derived from larger vessels.