Morphologic characteristics of retinal degeneration induced by sodium iodate in mice.
OBJECTIVE
Retinal degeneration induced by sodium iodate (NaIO( 3)) in mice was evaluated morphologically.


METHODS
Male and female ICR and C57BL mice were intraperitoneally administered 100 mg/kg NaIO(3) at 7 weeks of age, and were killed 6, 12, 24 hrs, and 3, 7 and 28 days after the treatment. Retinas were examined histologically, ultrastructurally, immunohistochemically, and by the TUNEL method.


RESULTS
Retinal degeneration was evoked in all NaIO(3)-treated mice. The primary site of damage appeared in the retinal pigment epithelial (RPE) cells followed by photoreceptor cell degeneration. Initially, the RPE cells showed necrosis starting 6 hrs post-NaIO(3), followed by photoreceptor outer segment disruption and photoreceptor cell apoptosis at 24 hrs; photoreceptor cell apoptosis peaked at day 3 and was completed by day 7. At day 3, Müller cell proliferation, macrophage migration within the retina, and regeneration of damaged RPE cells occurred. Finally at day 7 and day 28, the retina showed a mosaic pattern of relatively normal retina and areas lacking RPE cells and photoreceptor cells.


CONCLUSIONS
RPE cell necrosis followed by photoreceptor cell apoptosis and the resulting mosaic pattern of the retina phenotypically resembles gyrate atrophy of the choroid and retina.
Kiuchi
Katsuji
K
Department of Pathology II, Kansai Medical University, Osaka, Moriguchi, Japan.
Yoshizawa
Katsuhiko
K
Shikata
Nobuaki
N
Moriguchi
Kaei
K
Tsubura
Airo
A
D000818:Animals; D017209:Apoptosis; D005260:Female; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D007452:Iodates; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008813:Mice, Inbred ICR; D008854:Microscopy, Electron; D010786:Photoreceptor Cells / Q000473:pathology / Q000503:physiopathology; D010857:Pigment Epithelium of Eye / Q000473:pathology / Q000503:physiopathology; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D012162:Retinal Degeneration / Q000139:chemically induced* / Q000378:metabolism / Q000473:pathology* / Q000503:physiopathology
D005904:Glial Fibrillary Acidic Protein; D007452:Iodates; D018809:Proliferating Cell Nuclear Antigen; C032285:sodium iodate