Mitotic inhibition of ICR 2A frog cells exposed to 265-313 nm monochromatic ultraviolet wavelengths and photoreactivating light.

Exposure of ICR 2A frog cells to 265, 289, 302 or 313 nm U.V. radiation caused a decrease in the MI of the irradiated cells in a fluence-dependent fashion. Treatment of cells with PRL immediately after U.V.-irradiation resulted in a smaller decrease in the MI, demonstrating that pyrimidine dimers played a role in the mitotic inhibition induced by these U.V. wavelengths. The effect of PRL on 313 nm-irradiated cells was much smaller than for the other wavelengths tested, indicating that non-dimer photoproducts were of importance in the mitotic inhibition induced by this U.V. wavelength.