Exposure of bovine dermal tissue to ultraviolet light under the Antarctic ozone hole

Bovine dermis was exposed outdoors in the Antarctic in 2013 to study the skin damage caused by short-wavelength ultraviolet light under the ozone hole. Collagen was extracted from the exposed dermis with pepsin. The amount of solubilized collagen in the exposed dermis was only 20%-40% of that in dermis shielded from ultraviolet light. The dermis was most difficult to extract when exposed in summer, and then when exposed in spring. Differential scanning calorimetry was used to determine the melting endothermic behavior of the dermal tissue. The peak temperature was highest for the dermis exposed in summer. The exposed dermis was degraded with cyanogen bromide to determine whether cross-linking had occurred. Cross-linked peptides were detected in the dermis exposed in summer or spring, but the dermis exposed in autumn did not differ markedly from the light-shielded dermis. These data show that cross-linkages were readily formed in the collagen molecule chains in dermis exposed to ultraviolet light in summer, when solar elevation is highest and the period of sunshine is longest. A comparison of the dermis exposed in spring and that exposed in autumn showed that cross-linkages were formed more readily by ultraviolet light in spring, when the ozone hole occurred.