Election spin resonance studies of free radical formation and oxygen consumption of lens epithelium during ultraviolet exposure.
A long life election spin resonance (ESR) signal at g = 2.0006 was observed in the normal lens epithelium and cortical fibers. During ultraviolet (UV) exposure, a new ESR signal at g = 2.0060 was found in the lens epithelium. But this specific signal was not detected in the lens cortical fibers. This suggested that lens epithelial cells were more susceptible to the free radical formation which was induced by UV light. By means of ESR spin probe oximetry, the oxygen uptake of lens epithelial cells was measured. The more the oxygen uptake, the higher the K value was. The K value of the oxygen consumption of epithelial cell linearly correlated with time of consumption (20-60 min) and increased as a function of UV exposure time (1-5 min). The oxygen consumption rate of lens epithelial cell was approximately 1.38 x 10(6) and increased to 7.1 x 10(6) O2 molecules per cell per sec. The oxygen consumption rate increased more than 5 times. These results indicates that UV light can accelerate the respiratory function of lens epithelial cells. The necessity of excess oxygen of lens epithelial cells may play a role in the cataract formation induced by UV light.
Xu
J
J
Beijing Institute of Radiation Medicine, China.
Sun
C
C
Wu
K
K
Shao
J
J
Shan
Q
Q
Cong
J
J
Zhang
J
J
D000818:Animals; D004578:Electron Spin Resonance Spectroscopy; D004847:Epithelial Cells; D005609:Free Radicals; D007904:Lens Cortex, Crystalline / Q000166:cytology / Q000528:radiation effects; D007908:Lens, Crystalline / Q000166:cytology / Q000528:radiation effects*; D010101:Oxygen Consumption / Q000528:radiation effects*; D011817:Rabbits; D014466:Ultraviolet Rays / Q000009:adverse effects
D005609:Free Radicals