Quantitative alterations of hyaluronan and dermatan sulfate in the hairless mouse dorsal skin exposed to chronic UV irradiation

The quantitative alterations of hyaluronan and dermatan sulfate in the uppe r dermis (fibrous tissue) and the lower dermis (adipose tissue) of the hair less mouse skin chronically exposed to the UV irradiation as solar-simulati ng irradiation (lambda(max) 352 nm, UV distribution: 300-310 nm, 0.9%; 310- 320 nm, 2.0%; 320-420 nm, 97.1%) were evaluated. Hyaluronan and dermatan su lfate contents in each part of dermis were determined as follows: skin sect ions on a glass slide prepared by histological technique were processed int o the upper dermis and the lower dermis with a small surgical knife, and tr eated with chondroitinase ABC and ACII in the presence of bacterial collage nase. The resulting unsaturated disaccharides were determined by HPLC metho d. By applying this method to the UV-irradiated hairless mouse skin, it was found that the chronic UV irradiation increased dermatan sulfate in the up per dermis, whereas an increase of hyaluronan content was not statistically significant. In the lower dermis, on the contrary, both hyaluronan and der matan sulfate contents remarkably increased as compared with the control mi ce. Furthermore, the histological study showed the accumulation of the coll agen fibers in the lower dermis of the UV-irradiated hairless mouse skin fo llowing the disappearance of adipocytes. These findings indicate that the i ncreases of glycosaminoglycan contents in the UV-irradiated skin are relate d to the accumulation of the extracellular matrix components in the lower d ermis. (C) 1999 Elsevier Science B.V. All rights reserved.