Preservation of retinoid influx into eye tissues of ABCR-deficient mice.
Using an in vivo radiolabeling technique, we investigated the movement of retinoid into the retinal pigment epithelium (RPE) of the abcr-/- mouse, which lacks the photoreceptor ABCR protein and is a model for Stargardt disease. Eye tissues and serum obtained from dark-adapted, 5- to 8-month-old abcr-/- and control mice following the intraperitoneal injection of all-trans ((3)H)retinol were analyzed to determine the inferred influx of retinoid from the serum into the RPE. At 4.5 hr post-injection, the inferred all-trans retinol influx in abcr-/- mice, which possess the leucine 450 variant of RPE65 protein, was 0.011 +/- 0.004 nmol (n = 3). This value did not differ significantly from that determined in age-matched controls possessing the methionine 450 variant of RPE65 (0.015 +/- 0.003 nmol; n = 3) or from 3-month-old wildtype mice that possess the leucine 450 RPE65 variant (0.020 +/- 0.007; n = 4). Thus, the absence of ABCR does not significantly compromise the passage of retinoid from the serum into the RPE under dark-adapted conditions.
Qtaishat
Nasser M
NM
Lions of Illinois Eye Research Institute, Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, College of Medicine, Chicago 60612, USA.
Pepperberg
David R
DR
D018528:ATP-Binding Cassette Transporters / Q000502:physiology*; D000818:Animals; D001692:Biological Transport; D002352:Carrier Proteins / Q000378:metabolism; D003623:Dark Adaptation; D005136:Eye Proteins / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008268:Macular Degeneration / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D008817:Mice, Mutant Strains; D010857:Pigment Epithelium of Eye / Q000378:metabolism*; D012176:Retinoids / Q000378:metabolism*; D012374:Rod Cell Outer Segment / Q000378:metabolism; D019745:cis-trans-Isomerases; D000099178:Retinoid Isomerohydrolase
D018528:ATP-Binding Cassette Transporters; D002352:Carrier Proteins; D005136:Eye Proteins; D012176:Retinoids; D019745:cis-trans-Isomerases; D000099178:Retinoid Isomerohydrolase; C512841:Abca4 protein, mouse