title: The retina rapidly incorporates ingested C20-D₃-vitamin A in a swine model.
abstract: OBJECTIVE
  To determine how the retina uses vitamin A for vision, we studied the flux of oral vitamin A into and out of the swine retina.
  
  
  METHODS
  We administered labeled vitamin A to swine daily for 30 days and measured the percent of the labeled vitamin A to native unlabeled vitamin A in the retinal epithelium, neuroretina, plasma, liver, lung, and kidney.
  
  
  RESULTS
  We show that during normal vitamin A homeostasis, the retina rapidly assimilates newly ingested dietary vitamin A, which replaces native vitamin A. Retinal vitamin A is turned over faster than previously thought. Provitamin A carotenoids do not significantly contribute to retinal vitamin A pools when consuming diets adequate in vitamin A.
  
  
  CONCLUSIONS
  Fast vitamin A turnover in the retina has direct implications for emerging therapies to prevent major forms of blindness based on controlling the concentrations of retinal vitamin A.
authors.affiliation: Department of Ophthalmology, Columbia University Medical Center New York, NY, USA.
authors.forename: Doina M
authors.initials: DM
authors.lastname: Mihai
authors.forename: Hongfeng
authors.initials: H
authors.lastname: Jiang
authors.forename: William S
authors.initials: WS
authors.lastname: Blaner
authors.forename: Alexander
authors.initials: A
authors.lastname: Romanov
authors.forename: Ilyas
authors.initials: I
authors.lastname: Washington
mesh_terms: D000042:Absorption / Q000187:drug effects; D000818:Animals; D003903:Deuterium / Q000378:metabolism*; D008297:Male; D023421:Models, Animal; D008954:Models, Biological; D012160:Retina / Q000187:drug effects* / Q000378:metabolism*; D034421:Sus scrofa; D014801:Vitamin A / Q000494:pharmacology*
chemical_list: D014801:Vitamin A; D003903:Deuterium
references.citation: Biochemistry. 2006 Jan 24;45(3):852-60
references.pmid: 16411761
references.citation: J Lipid Res. 1996 Sep;37(9):1875-85
references.pmid: 8895053
references.citation: Retina. 2013 Mar;33(3):498-507
references.pmid: 23023528
references.citation: Retina. 2012 Jan;32(1):183-8
references.pmid: 21519291
references.citation: Am J Clin Nutr. 2012 Nov;96(5):1234S-44S
references.pmid: 23053549
references.citation: Biochim Biophys Acta. 2009 Jul;1791(7):573-83
references.pmid: 19230850
references.citation: Science. 2007 Feb 9;315(5813):820-5
references.pmid: 17255476
references.citation: Proc Natl Acad Sci U S A. 1958 Jul 15;44(7):648-61
references.pmid: 16590255
references.citation: J Nutr. 2008 Jun;138(6):1101-6
references.pmid: 18492841
references.citation: Arch Ophthalmol. 2012 Jun;130(6):707-11
references.pmid: 22332205
references.citation: Cancer Treat Rep. 1984 Sep;68(9):1125-33
references.pmid: 6478452
references.citation: J Biol Chem. 1975 May 25;250(10):3613-9
references.pmid: 1092676
references.citation: Proc Natl Acad Sci U S A. 1939 Jul;25(7):344-9
references.pmid: 16577912
references.citation: Toxicol Appl Pharmacol. 1991 Oct;111(1):116-27
references.pmid: 1949028
references.citation: EMBO J. 1999 Sep 1;18(17):4633-44
references.pmid: 10469643
references.citation: Invest Ophthalmol Vis Sci. 1999 Jan;40(1):3-11
references.pmid: 9888420
references.citation: Am J Clin Nutr. 1999 May;69(5):931-6
references.pmid: 10232633
references.citation: J Biol Chem. 2011 Mar 11;286(10):7966-7974
references.pmid: 21156790
references.citation: Am J Clin Nutr. 2005 Apr;81(4):851-8
references.pmid: 15817863
references.citation: J Nutr. 2006 Apr;136(4):939-45
references.pmid: 16549454
references.citation: J Nutr. 1969 Oct;99(2):129-36
references.pmid: 5346545
references.citation: J Nutr. 2004 May;134(5):1186-92
references.pmid: 15113968
references.citation: Vitam Horm. 1974;32:251-75
references.pmid: 4617402
references.citation: J Nutr. 1950 Feb;40(2):275-9
references.pmid: 15406204
references.citation: J Nutr. 2003 Feb;133(2):609S-23S
references.pmid: 12566511
references.citation: Vision Res. 1986;26(3):425-9
references.pmid: 3727408
references.citation: Annu Rev Nutr. 1987;7:361-82
references.pmid: 3300739
references.citation: Can J Comp Med. 1984 Oct;48(4):390-3
references.pmid: 6509366
references.citation: Invest Ophthalmol Vis Sci. 1977 Dec;16(12):1110-7
references.pmid: 924741
references.citation: Am J Clin Nutr. 2007 Oct;86(4):1045-53
references.pmid: 17921383
references.citation: J Pharm Sci. 1982 Oct;71(10):1073-96
references.pmid: 6754906
references.citation: J Biol Chem. 2005 Oct 21;280(42):35647-57
references.pmid: 16115871
references.citation: Science. 1997 Sep 19;277(5333):1805-7
references.pmid: 9295268
references.citation: Int J Vitam Nutr Res. 1989;59(4):329-32
references.pmid: 2634037
references.citation: J Biol Chem. 2008 Apr 11;283(15):9543-54
references.pmid: 18195010
references.citation: Arch Ophthalmol. 1986 Jan;104(1):69-70
references.pmid: 2935125
references.citation: Novartis Found Symp. 2004;255:51-63; discussion 63-7, 177-8
references.pmid: 14750596
references.citation: J Biol Chem. 2011 Mar 11;286(10):7958-7965
references.pmid: 21075840
references.citation: Exp Eye Res. 1975 Oct;21(4):359-367
references.pmid: 1218543