Damaging effects of visible light. (Progress report)

Technical Report · Mon Jan 01 04:00:00 EST 1979

OSTI ID:5852473

Williams, T P

When rats are exposed to low intensities of light for extended periods of time, they suffer the death of their visual photoreceptors. The proposal is aimed at elucidating the mechanisms whereby the damage occurs. Specifically, the proposal considers photodynamic oxidation of retinal cells as a possible cause of damage and, eventually, death. A brief review of the importance of photodynamic action is given and its relationship to visual cells is pointed out. It is shown, for example, that the components of visual pigments, themselves, are candidates both for producing singlet oxygen (a known cellular oxidant) and for becoming damaged. Thus, a scheme is proposed as one possibility: retinaldehyde, the visual chromophore, sensitizes the production of singlet oxygen which then oxidizes the highly unsaturated fatty acids of the membrane lipids. The oxidation products (chiefly aldehydes), in turn, attack amino groups on the visual pigment protein, opsin, and render it unable to properly regenerate visual pigment. ''Lipofusin'' fluorescence in receptors will be determined and the rate and extent of pigment regeneration will be ascetained. Preliminary results are given. 56 refs., 2 figs.

• Research Organization: Florida State Univ., Tallahassee (USA)
• DOE Contract Number: AS05-78OR06021
• OSTI ID: 5852473
• Report Number(s): DOE/OR/06021-1; ON: DE85010343
• Country of Publication: United States
• Language: English

Related Subjects

560400* -- Other Environmental Pollutant Effects
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMALS
BIOLOGICAL EFFECTS
BODY
BODY AREAS
CELL KILLING
CHEMICAL REACTIONS
ELECTROMAGNETIC RADIATION
EYES
FACE
HEAD
MAMMALS
ORGANS
OXIDATION
PIGMENTS
RADIATIONS
RATS
RETINA
RODENTS
SENSE ORGANS
VERTEBRATES
VISIBLE RADIATION