Structural photomodification of erythrocyte ghosts by long wave UV light and psoralen

The two hour dark reaction of 8-methoxypsoralen (8-MOP) (15 μg/ml) with erythrocyte ghosts, and their irradiation with long wave UV light (UV-A) (2.1 mW/cm 2 ) for the same period has resulted either in partial or total obliteration of membrane ultrastructure, respectively. However, the irradiation of ghosts in the presence of 8-MOP tended to stabilize structurally distinct membrane components and has also promoted the formation of spherically-lamellar intermembranous bodies. In their turn, the formation of intermembranous bodies was attributed to the UV-A-mediated cross-linking of membrane lipids by 8-MOP. It is therefore concluded that photomodification of erythrocyte ghosts by psoralen proceeds via independent, but concurrent reaction of this photosensitizer with the erythrocyte membrane lipids and with proteins.