title: Drinking water supplementation with ascorbate is not protective against UVR-B-induced cataract in the guinea pig.
abstract: OBJECTIVE
  To study if ascorbate supplementation decreases ultraviolet radiation (UVR)-induced cataract development in the guinea pig.
  
  
  METHODS
  Sixty 6-9-week-old pigmented guinea pigs received drinking water supplemented with or without 5.5 mm l-ascorbate for 4 weeks. After supplementation, 40 animals were exposed unilaterally in vivo under anaesthesia to 80 kJ/m(2) UVR-B. One day later, the animals were killed and lenses were extracted. Degree of cataract was quantified by measurement of intensity of forward lens light scattering. Lens ascorbate concentration was determined with high-performance liquid chromatography (HPLC) with UVR detection at 254 nm. Twenty animals were used as non-exposed control.
  
  
  RESULTS
  Supplementation increased lens ascorbate concentration significantly. In UVR-exposed animals, mean 95% confidence intervals (CIs) for animal-averaged lens ascorbate concentration (micromol/g wet weight lens) were 0.54 +/- 0.07 (no ascorbate) and 0.83 +/- 0.05 (5.5 mm ascorbate). In non-exposed control animals, mean 95% CIs for animal-averaged lens ascorbate concentration (micromol/g wet weight lens) were 0.72 +/- 0.12 (0 mm ascorbate) and 0.90 +/- 0.15 (5.5 mm ascorbate). All non-exposed lenses were devoid of cataract. Superficial anterior cataract developed in all UVR-exposed lenses. The lens light scattering was 39.2 +/- 14.1 milli transformed equivalent diazepam concentration (m(tEDC)) without and 35.9 +/- 14.0 m(tEDC) with ascorbate supplementation.
  
  
  CONCLUSIONS
  Superficial anterior cataract develops in lenses exposed to UVR-B. Ascorbate supplementation is non-toxic to both UVR-B-exposed lenses and non-exposed control lenses. Ascorbate supplementation does not reduce in vivo lens forward light scattering secondary to UVR-B exposure in the guinea pig.
authors.affiliation: St Erik's Eye Hospital, Karolinska Institute, Stockholm, Sweden. vino.mody@ste.ki.se
authors.forename: Vino C
authors.initials: VC
authors.lastname: Mody
authors.forename: Manoj
authors.initials: M
authors.lastname: Kakar
authors.forename: Ase
authors.initials: A
authors.lastname: Elfving
authors.forename: Stefan
authors.initials: S
authors.lastname: Löfgren
mesh_terms: D000818:Animals; D001205:Ascorbic Acid / Q000008:administration & dosage* / Q000378:metabolism / Q000494:pharmacology; D002386:Cataract / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control*; D004326:Drinking; D006168:Guinea Pigs; D007908:Lens, Crystalline / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects*; D008027:Light; D011833:Radiation Injuries, Experimental / Q000503:physiopathology / Q000517:prevention & control*; D012542:Scattering, Radiation; D014466:Ultraviolet Rays / Q000009:adverse effects*; D014867:Water
chemical_list: D014867:Water; D001205:Ascorbic Acid