Multimodal Fundus Imaging of Sodium Iodate-Treated Mice Informs RPE Susceptibility and Origins of Increased Fundus Autofluorescence.

Title Multimodal Fundus Imaging of Sodium Iodate-Treated Mice Informs RPE Susceptibility and Origins of Increased Fundus Autofluorescence.
Authors J. Zhao; H.Jin Kim; J.R. Sparrow
Journal Invest Ophthalmol Vis Sci
DOI 10.1167/iovs.17-21557
Abstract

Purpose: By multimodal imaging, and the use of mouse and in vitro models, we have addressed changes in fundus autofluorescence (488 and 790 nm) and observed interactions between the photooxidative stress imposed by RPE bisretinoid lipofuscin and the oxidative impact of systemic sodium iodate (NaIO3).

Methods: Abca4-/-, wild-type, and Rpe65rd12 mice were given systemic injections of NaIO3 (30 mg/kg). Analysis included noninvasive imaging of fundus autofluorescence (short-wavelength [SW-AF]; near-infrared excitation [NIR-AF]), quantitative fundus AF (qAF; 488 nm); light microscopy, RPE flat-mounts and measurements of outer nuclear layer (ONL) thickness. NaIO3 also was studied by using in vitro assays.

Results: In SW-AF and NIR-AF images, fundus mottling was visible 3 and 7 days after NaIO3 injection with changes being more pronounced in Abca4-/- mice that are characterized by an abundance of RPE bisretinoid lipofuscin. In Abca4-/- mice, qAF was elevated 3 and 7 days after NaIO3 administration. In light micrographs and RPE flat-mounts stained to reveal tight junctions (ZO-1) and nuclei, the RPE monolayer was disorganized, and clumping and loss of RPE was visible. ONL thinning was most pronounced in Abca4-/- mice. Treatment of ARPE-19 cells with NaIO3 together with the photooxidation of the bisretinoid A2E by exposure to 430-nm light produced an additive effect whereby loss of cell viability was greater than with either perturbation alone.

Conclusions: Elevations in SW-AF intensity can occur due to photoreceptor cell dysfunction as induced secondarily by NaIO3. Photooxidative stress associated with RPE cell bisretinoid lipofuscin may confer increased susceptibility to the oxidant NaIO3.

Citation J. Zhao; H.Jin Kim; J.R. Sparrow.Multimodal Fundus Imaging of Sodium Iodate-Treated Mice Informs RPE Susceptibility and Origins of Increased Fundus Autofluorescence.. Invest Ophthalmol Vis Sci. 2017;58(4):21522159. doi:10.1167/iovs.17-21557

Related Elements

Sodium

Sodium Bohr ModelSee more Sodium products. Sodium (atomic symbol: Na, atomic number: 11) is a Block D, Group 5, Period 4 element with an atomic weight of 22.989769. The number of electrons in each of Sodium's shells is [2, 8, 1] and its electron configuration is [Ne] 3s1. The sodium atom has a radius of 185.8 pm and a Van der Waals radius of 227 pm. Sodium was discovered and first isolated by Sir Humphrey Davy in 1807. In its elemental form, sodium has a silvery-white metallic appearance. It is the sixth most abundant element, making up 2.6 % of the earth's crust. Sodium does not occur in nature as a free element and must be extracted from its compounds (e.g., feldspars, sodalite, and rock salt). The name Sodium is thought to come from the Arabic word suda, meaning "headache" (due to sodium carbonate's headache-alleviating properties), and its elemental symbol Na comes from natrium, its Latin name.

Iodine

See more Iodine products. Iodine (atomic symbol: I, atomic number: 53) is a Block P, Group 17, Period 5 element with an atomic radius of 126.90447. The number of electrons in each of Iodine's shells is 2, 8, 18, 18, 7 and its electron configuration is [Kr] 4d10 5s2 5p5. The iodine atom has a radius of 140 pm and a Van der Waals radius of 198 pm. In its elemental form, iodine has a lustrous metallic gray appearance as a solid and a violet appearance as a gas or liquid solution. Elemental IodineIodine forms compounds with many elements, but is less active than the other halogens. It dissolves readily in chloroform, carbon tetrachloride, or carbon disulfide. Iodine compounds are important in organic chemistry and very useful in the field of medicine. Iodine was discovered and first isolated by Bernard Courtois in 1811. The name Iodine is derived from the Greek word "iodes" meaning violet.

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