Uchino, T., H. Tokunaga, and M. Ando. 1999. ProstaglandinE₂ Release, Squalene Monohydroperoxide Production and Cell Toxicity of Skin^2TM ZK1301 as a Human Skin Model in the Presence of Haematoporphylin and Ultraviolet-A Irradiation. Toxic. in Vitro 13: 483-489.

For the clarification of the mechanism of ultraviolet-A (UVA)-induced cytotoxicity to skin, the prostaglandinE₂ (PGE₂) release and squalene monohydroperoxide (SQOOH) production in a human skin model (Skin^2TM ZK1301) in the presence of haematoporphylin (HP) as a photosensitizer were investigated. The PGE₂ release and SQOOH production were significantly increased depending on both the irradiation time of UVA (350-380 nm) and the HP concentration. In addition, concentration-dependent inhibitions of cytotoxicity, PGE₂ release and SQOOH production were observed when a UVA sunscreen was applied to the Skin^2TM. These results suggest that the mediator of inflammation and lipid hydroperoxide production induced by UVA-HP photosensitization cause cytotoxicity to skin, and that the test method of UVA-HP photosensitization using the Skin^2TM ZK1301 model is a useful in vitro model for studying UVA phototoxicity and for UVA sunscreen evaluations.