Effect of combined AZQ and radiation on the tolerance of the rat spinal cord.

The effect of combined AZQ (aziridinylbenzoquinone) and ionizing radiation on the rat spinal cord has been investigated. The highest dose of AZQ (3 mg/kg) tolerated by rats weighing 250 g was injected intravenously 15 min before a single dose of radiation or the first of 2 fractional doses. The development of paralysis due to white-matter necrosis in rats of each dose group was scored and dose-response curves were constructed. It has been found that a combination of AZQ with radiation did not lead to a significant shift of the dose-response curve as compared to that of radiation alone. Thus, AZQ administered according to the schedule used in the present study did not seem to reduce the radiation tolerance of the central nervous system.