Comparative investigations of the effect of angular and linear psoralen derivatives on human cultured lymphocytes

Angular psoralens induce compared to linear derivatives significantly more lethally damaged cultured human lymphocytes after photosensitization. While linear psoralens cause an inhibition of the phytohemagglutinin (PHA) transformation rate independent on the time of addition to the cultures, this happens with angular derivatives only in the case of simultaneous addition of psoralen and PHA. When PHA was added to the cultures before angelicins or vice versa, normal transformation rates or significant higher transformation rates were observed, respectively. Angular psoralens alterate lymphocyte function in a different way compared to linear derivatives, this could be important concerning their therapeutic application. (author)