title: Vitamin A supplementation ameliorates obesity-associated retinal degeneration in WNIN/Ob rats.
abstract: OBJECTIVE
  Obesity is associated with various health afflictions, including ocular complications such as diabetic retinopathy, high intraocular pressure, cataracts, and macular degeneration. We previously reported progressive retinal degeneration after the onset of obesity in the spontaneously obese rat (WNIN/Ob) model. In the present study, we investigated vitamin A supplementation to ameliorate obesity-associated retinal degeneration in the WNIN/Ob rat.
  
  
  METHODS
  Five-month-old male WNIN/Ob obese (O) and lean (L) control rats were fed with vitamin A 2.6 mg (L/O-I), 26 mg (L/O-II), 52 mg (L/O-III), and 129 mg (L/O-IV) per kilogram of diet as retinyl palmitate for 4 mo 2 wk. Retinal morphology and retinal gene expression were assessed by histologic, immunohistochemical, and real-time polymerase chain reaction methods.
  
  
  RESULTS
  Supplementation of vitamin A at 26 or 52 mg significantly modulated the expression of retinal genes in the O but not in the L phenotype. Vitamin A supplementation significantly upregulated the expression of genes, such as rhodopsin, rod arrestin, phosphodiesterase, transducins, and fatty acid elongase-4, that were otherwise downregulated in O rat retina. The expression of glial fibrillary acidic protein was downregulated by vitamin A feeding in O rat retina. The immunohistochemical and histologic findings corroborated the gene expression data. The effects were significant at a 26- or 52-mg dose of vitamin A.
  
  
  CONCLUSIONS
  Vitamin A supplementation alleviated obesity-associated retinal degeneration in the WNIN/Ob rat.
authors.affiliation: Department of Biochemistry, National Institute of Nutrition, Hyderabad, India.
authors.forename: Mrudula
authors.initials: M
authors.lastname: Tiruvalluru
authors.forename: Prashanth
authors.initials: P
authors.lastname: Ananthathmakula
authors.forename: Vajreswari
authors.initials: V
authors.lastname: Ayyalasomayajula
authors.forename: Giridharan
authors.initials: G
authors.lastname: Nappanveettil
authors.forename: Radha
authors.initials: R
authors.lastname: Ayyagari
authors.forename: Geereddy Bhanuprakash
authors.initials: GB
authors.lastname: Reddy
mesh_terms: D000123:Acetyltransferases / Q000235:genetics; D000818:Animals; D019393:Arrestin / Q000235:genetics; D001483:Base Sequence; D017931:DNA Primers / Q000235:genetics; D000081031:Fatty Acid Elongases; D015870:Gene Expression / Q000187:drug effects; D005904:Glial Fibrillary Acidic Protein / Q000235:genetics; D007150:Immunohistochemistry; D008297:Male; D009765:Obesity / Q000150:complications* / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism; D051381:Rats; D012160:Retina / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D012162:Retinal Degeneration / Q000209:etiology / Q000235:genetics / Q000378:metabolism / Q000517:prevention & control*; D012243:Rhodopsin / Q000235:genetics / Q000378:metabolism; D014801:Vitamin A / Q000008:administration & dosage*
chemical_list: D019393:Arrestin; D017931:DNA Primers; D005904:Glial Fibrillary Acidic Protein; D014801:Vitamin A; D012243:Rhodopsin; D000123:Acetyltransferases; D000081031:Fatty Acid Elongases