Attenuation of ultraviolet radiation-induced edema and erythema with topical calmodulin and protein kinase C inhibitors.

We treated Skh:HR1 hairless albino mice, NSA mice and hairless albino guinea pigs topically with N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W7) or trifluoperazine (TFP) before or after ultraviolet (UV) irradiation. When applied before irradiation, W7 and TFP prevented edema in Skh-1 mice and W7 prevented UV-induced edema in NSA mice in a dose-dependent manner. Preirradiation treatment with 2% W7 reduced erythema in guinea pigs by 50%. Epidermal histology of UVR-treated Skh-1 mice pretreated with W7 before UVR was similar to unirradiated mice. W7 did not reverse or prevent these UV-induced effects when applied after irradiation. Neither TFP nor W7 absorbed UV based on forward scattering absorbance spectra; we conclude that neither are physical or chemical sunscreens. These results suggest that calmodulin and/or protein kinase C-dependent events are involved in manifesting some of the effects of UV irradiation on skin.