Figure 1.

Effect of UVB radiation on CHS response and the levels of inflammatory mediators. The shaved dorsal skin of female C3H/HeN mice was exposed to UVB radiation (150 mJ/cm²) on four consecutive days as described in Materials and Methods section. (A) The mice were sensitized to DNFB, and the CHS response to application of DNFB on ear skin (challenge) was assessed by measurement of the ear swelling response 24 hours later as described in Materials and Methods section. The change in ear skin thickness is reported in millimeter (x 10^-2) as the mean ± SD, with n = 4 to 5 per group. (B–D) The mice were exposed to UVB (150 mJ/cm²) on four consecutive days and then sacrificed 24 hours after the last UVB exposure. Dorsal skin samples from UVB-exposed and non-UVB-exposed mice were collected for analysis. (B) The levels of COX-2 were determined in lysates of the skin using Western blot analysis. (C) The concentration of PGE₂ was determined in homogenates of the epidermis using an ELISA kit. PGE₂ concentration is expressed in terms of pg/mg protein as the mean ± SD. (D) The levels of expression of the PGE₂ receptors (EP1, EP2, EP3, and EP4) were determined by Western blot analysis. To recognize and verify the exact band of EP receptors, a positive control of individual EP receptor was run on the same gel. For B to D, data are shown in duplicates, and each sample was prepared by pooling the skin biopsies from at least two mice in each group. Std., standards or positive controls of EP receptors.