Lysosomes: a possible target for psoralen photodamage.
Treatment in vitro of Ehrlich ascites tumor cells or human fibroblasts with 8-methoxypsoralen (8-MOP, 2.4 microM) and UVA irradiation results in a 30% and 60% respectively reduction in lysosomal beta-galactosidase activity in situ. Under identical conditions one 8-MOP adduct was formed per 2 X 10(4) bases of DNA, one 8-MOP adduct was formed per approximately 10(4) tRNA molecules and one per approximately 100 ribosomes. It is suggested that the decrease in lysosomal beta-galactosidase activity is a result of leakage through the lysosomal membrane caused by psoralen-UVA damage of the lipids in the membrane, since no effect was found on beta-galactosidase in vitro. These results indicate that the lysosomes may also be a target for cellular photodamage by 8-methoxy-psoralen.
Frederiksen
S
S
Department of Biochemistry B, Panum Institute, Copenhagen, Denmark.
Nielsen
P E
PE
Høyer
P E
PE
D001345:Autoradiography; D002855:Chromatography, Thin Layer; D004247:DNA / Q000187:drug effects; D005347:Fibroblasts / Q000201:enzymology; D006801:Humans; D050356:Lipid Metabolism; D008247:Lysosomes / Q000187:drug effects* / Q000201:enzymology; D008730:Methoxsalen / Q000494:pharmacology*; D011701:PUVA Therapy; D011506:Proteins / Q000378:metabolism; D012313:RNA / Q000187:drug effects; D014407:Tumor Cells, Cultured / Q000201:enzymology; D001616:beta-Galactosidase / Q000378:metabolism
D011506:Proteins; D012313:RNA; D004247:DNA; D001616:beta-Galactosidase; D008730:Methoxsalen