MEMBRANE DAMAGE INDUCED IN CULTURED HUMAN SKIN FIBROBLASTS BY UVA IRRADIATION

Abstract

Irradiation of cultured human skin fibroblasts with ultraviolet light from 320 to 400 nm (UVA) leads to a decrease in the membrane fluidity exemplified by an enhanced fluorescence anisotropy of the lipophilic fluorescent probe 1‐[4‐trimethylamino)‐phenyl]‐6‐phenylhexa‐1,3,5‐triene. This UVA‐induced decrease in fluidity is associated with lactate dehydrogenase leakage in the supernatant. Vitamin E, an inhibitor of lipid peroxidation, exerts a protective effect on both phenomena. Therefore, this UVA‐induced damage in membrane properties may be related to lipid peroxidation processes. Moreover, exponentially growing cells are more sensitive to these UVA‐induced alterations than confluent cells.