Photohemolysis sensitized by psoralen: reciprocity law is not fulfilled.

The effect of the intensity of ultraviolet-A (UV-A) radiation (366 nm) on delayed photohemolysis sensitized by psoralen (PUV-A hemolysis) was studied. It was shown that PUV-A hemolysis induced by UV-A radiation at low fluence rate (20 W m-2) develops according to the well-known colloid-osmotic mechanism: there was no threshold dose of PUV-A treatment. After irradiation all the cells were hemolysed.

[Effect of photo-oxidized psoralen on the permeability of erythrocyte and liposome membranes].

Hemolysis of erythrocytes was induced after addition of ethanol solution of photooxidized psoralen, while the substance irradiated in absence of oxygen did not cause the cells hemolysis. The rate of hemolysis correlated with concentration of photooxidized psoralen in a sigmoid type. Similar concentration-dependent effect has been known for digitonin.