Singlet oxygen and ultraweak chemiluminescence in rat skin.

The intensity of ultraweak chemiluminescence (CL) was estimated in rat epidermal homogenate with a technique utilizing UV irradiation (in vitro and in vivo). CL markedly increased in the homogenate after irradiation. The CL intensity was enhanced to 300% by the substitution of deuterium oxide for H2O, and it was reduced to 50% when diazabicyclo-octane, a scavenger for singlet oxygen, was added. It was concluded that the weak CL would be attributable to singlet oxygen, and the determination of the lipoperoxide in skin tissue by the method of the CL counting system was discussed.