Dose-modifying effect of misonidazole on the radiation response of growing cartilage in mice.

Misonidazole administered before a single dose of 15 Gy X-rays enhances the radiation response of growing bone in mice by a factor 1.3. In combination with split-dose irradiation of twice 7.5 Gy the drug did not cause significant enhancement. These results are most likely due to the existence of hypoxic cells in growing cartilage as has been demonstrated already by other authors.