[Rad-equivalences for mono-and bifunctional furocoumarins (author's transl)].

Rad-equivalences were established for four mono- and bifunctional furocoumarins, two of them of therapeutical interest. Using an eucaryotic cell system (Saccharomyces cerevisiae) rad-equivalences were determined for lethal effects, the induction of mutations and of intra- and intergenic recombination. For each furocoumarin the rad-equivalences for the genetic effects lay in the same range except those for the induction of intergenic recombination which gave higher values. Based on data obtained on mammalian cells in culture a rad-equivalence could be estimated for the phototoxic effect (cell killing effect) of 8-methoxypsoralen used in PUVA-therapy.