Fig. 2.

Effect of voluntary RW exercise, oral administration of caffeine, or a combination of exercise and caffeine on UVB-induced apoptosis in the epidermis. SKH-1 mice (10 per group) were treated with RW exercise, oral caffeine [0.1 or 0.4% in the drinking water (0.1 or 0.4 CF)], or a combination of RW and CF for 2 weeks. Apoptotic sunburn cells and caspase 3 (active form)-positive cells in the epidermis were determined at 6 h after irradiation with UVB (30 mJ/cm²). Using Tukey's multiple comparison test for apoptotic sunburn cell measurements, we found that the CF (0.1) + RW group was different from the CF (0.1) group in experiments 1 and 2 and from the RW group in experiments 1 and 2. For the caspase 3 measurements, the CF (0.1) + RW group was different from the CF (0.1) group in experiments 1 and 2 and from the RW group in experiments 1 and 2.