Membrane damage caused by 8-MOP and UVA-treatment of cultivated cells.

Treatment of red blood cells with a combination of 8-MOP and UVA did not cause any significant hemolysis under the experimental conditions used, and the deuterium test for identification of singlet oxygen mediated reactions was negative. However, similar experiments performed on in vitro cultivated human glia cells caused conspicuous surface membrane alterations, as revealed by scanning electron microscopy. The alterations were seen at higher concentration levels than was expected and might be secondary to earlier appearing intracellular events seen at lower concentrations. The clinical significance of membrane alterations for the results obtained with PUVA therapy require further investigation.