Ascorbate in the rat lens: dependence on dietary intake
2005 (English)In: Ophthalmic Research, ISSN 0030-3747, E-ISSN 1423-0259, Vol. 37, no 3, 142-149 p.Article in journal (Refereed) Published
PURPOSE: To establish a method for sample preparation to measure ascorbate in whole lenses and to investigate whether lens ascorbate concentration is dependent on dietary ascorbate intake. METHODS: Four groups of 3 young Sprague-Dawley rats each were fed chow containing L-ascorbate, either 0.0, 5.7, 57.0 or 114.0 mmol/kg for a duration of 4 weeks. Thereafter, each rat was sacrificed. The lens was extracted, photographed, and lens wet weight was measured. The lens was homogenized in 1.0 ml of 0.25% metaphosphoric acid, the homogenate was centrifuged and the supernatant ultrafiltered. The filtrate was injected into an ion exchange, reversed-phase Polypore H HPLC column equipped with a 254-nm ultraviolet detector. Samples were calibrated against an L-ascorbate standard. Polynomial regression analysis was performed on the data. RESULTS: All lenses were devoid of cataract. A 95% confidence interval for baseline content of ascorbate without any dietary intake was estimated to be 0.16+/-0.01 micromol/g wet weight of lens. The lens ascorbate concentration increased linearly with dietary ascorbate intake with an increased rate, estimated as a 95% confidence interval of 0.33+/-0.18 (micromol ascorbate) (g lens)-1)(mol ascorbate)-1 (kg chow) with r2=0.62. CONCLUSION: Lens ascorbate concentration linearly increases with dietary ascorbate intake without cataract development in the rat. The currently presented method for sample preparation to measure the whole-lens content of ascorbate is applicable.
Place, publisher, year, edition, pages
2005. Vol. 37, no 3, 142-149 p.
ascorbate, rat lens
IdentifiersURN: urn:nbn:se:uu:diva-104232DOI: 10.1159/000085534ISI: 000230597700005PubMedID: 15867476OAI: oai:DiVA.org:uu-104232DiVA: diva2:220265