Effect of chronic near-ultraviolet radiation on the gray squirrel lens in vivo.
The effects of ambient exposure to near-ultraviolet (near-UV) radiation (300-400 nm) on the ocular lens of the diurnal squirrel (Sciurus carolinensis) are reported. Gray squirrels lived in cages illuminated for 12 hr a day with near-UV light (6 mW/cm2, 365 nm) for 1 yr. The non-UV-exposed controls were housed separately. In the lenses of UV-exposed animals, anterior pole changes occurred. Central epithelial cells swelled, disappeared, or underwent proliferation. A band of disoriented degenerating fiber cells was seen in the midcortex, with a degree of liquefaction. When lens protein compartments were separated by centrifugation, water-insoluble but urea-soluble fractions were enhanced in the outer and inner cortex and the nucleus. Both high-performance liquid chromatography and polyacrylamide gel electrophoresis revealed that proteins mainly in the midcortex and nucleus were altered considerably. Evidence of a loss of sulfhydryl compounds (by chemical and Raman spectroscopic analyses) and an increase of protein-thiol mixed disulfides (chemically) was also observed. These data prove that repetitive ambient exposure of diurnal animals to near-UV radiation at subsolar levels damages the lens by interfering with the maintenance of epithelial cells and altering the structural proteins; some of this may be due to the conversion of sulfhydryls to mixed disulfides.
Zigman
S
S
Ophthalmology Research Laboratory, University of Rochester School of Medicine and Dentistry, New York.
Paxhia
T
T
McDaniel
T
T
Lou
M F
MF
Yu
N T
NT
D000818:Animals; D002386:Cataract / Q000209:etiology* / Q000473:pathology; D002851:Chromatography, High Pressure Liquid; D003459:Crystallins / Q000528:radiation effects; D004220:Disulfides / Q000528:radiation effects; D004591:Electrophoresis, Polyacrylamide Gel; D004848:Epithelium / Q000528:radiation effects; D007904:Lens Cortex, Crystalline / Q000528:radiation effects; D007907:Lens Nucleus, Crystalline / Q000528:radiation effects; D007908:Lens, Crystalline / Q000473:pathology / Q000528:radiation effects*; D011817:Rabbits; D011833:Radiation Injuries, Experimental / Q000473:pathology; D012589:Sciuridae; D013438:Sulfhydryl Compounds / Q000528:radiation effects; D014466:Ultraviolet Rays / Q000009:adverse effects*
D003459:Crystallins; D004220:Disulfides; D013438:Sulfhydryl Compounds