Mechanism of the formation of x-ray-induced phosphenes. II. Photochemical investigations

Journal Article · Sun Jun 01 00:00:00 EDT 1980 · Radiat. Res.; (United States)

DOI:https://doi.org/10.2307/3575310· OSTI ID:5025837

Doly, M; Isabelle, D B; Vincent, P; Gaillard, G; Meyniel, G

Like visible light, x rays can stimulate the isolated retina and induce an action potential (ERG). To explain the modalities of interaction of incident radiation with the photoreceptor cells, we studied the modifications of the rhodopsin absorption spectrum after x irradiation. For exposures smaller than 5 x 10/sup 5/ R, a large increase in absorption in the uv part of the spectrum is observed. For exposure of 1.25 x 10/sup 6/ R, a 20% decrease is measured in the characteristic peak of rhodopsin (500 nm). In comparison to what is known for visible light, the significant bleaching of rhodopsin by x rays can account for the initiation of an ERG in the isolated retina. By analogy with the enzymatic inactivation after x irradiation, we believe that the x-ray rhodopsin bleaching could be due to an energy transfer from the opsin to the attachment site of the chromophoric group (11-cis retinal). The disorganization of this critical site of the molecule could be at the origin of the rod excitation, then of the ERG.

• Research Organization: Laboratoire de Biophysique, Clermont-Ferrand, France
• OSTI ID: 5025837
• Journal Information: Radiat. Res.; (United States), Vol. 82:3
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
59 BASIC BIOLOGICAL SCIENCES
PIGMENTS
CHEMICAL RADIATION EFFECTS
RETINA
BIOCHEMICAL REACTION KINETICS
ABSORPTION SPECTRA
COMPARATIVE EVALUATIONS
EXPERIMENTAL DATA
RADIATION DOSES
RATS
SPECTRAL FUNCTIONS
VISIBLE RADIATION
X RADIATION
ANIMALS
BODY
BODY AREAS
CHEMISTRY
DATA
DOSES
ELECTROMAGNETIC RADIATION
EYES
FACE
FUNCTIONS
HEAD
INFORMATION
IONIZING RADIATIONS
KINETICS
MAMMALS
NUMERICAL DATA
ORGANS
RADIATION CHEMISTRY
RADIATION EFFECTS
RADIATIONS
REACTION KINETICS
RODENTS
SENSE ORGANS
SPECTRA
VERTEBRATES
560111* - Radiation Effects on Biochemicals- In Vitro- (-1987)
550200 - Biochemistry
551000 - Physiological Systems